path: root/defender.ca65

; da65 V2.16 - Git 6de78c5
; Created:    2017-09-22 19:42:52
; Input file: defender.rom
; Page:       1


        .setcpu "6502"

; ----------------------------------------------------------------------------
POKMSK          := $0010
RTCLOK          := $0012
ATRACT          := $004D
preshift_ptr    := $0080                        ; argument to preshift_sprite
tmp_y           := $0082
tmp_hoffset_l   := $0083
tmp_height      := $0084
animation_counter:= $0085                       ; for animated sprites, used to decide which frame to draw
level_jiffies_lo:= $0087                        ; init to 0 at start of level, increments every frame while game is playing
ship_move_delay := $0093                        ; counts 0-$FF (XXX how often? per-frame?), ship only moves (?) when low 2 bits == 3 (?)
level           := $009A                        ; player 1 only?
landers_to_spawn:= $009B                        ; total # of landers to spawn, on this level. each wave is max(landers_to_spawn, 5) landers, until landers_to_spawn == 0.
enemy_count     := $009C                        ; total number of live enemies on level, not counting baiters.
baiter_count    := $009D                        ; count of baiters on level. also used for some other purpose XXX what?
lives           := $009E                        ; player 1 only?
planet_dead_flag:= $00A0                        ; bit 7 set = planet has exploded (no humans, all mutants)
humanoid_count  := $00A1                        ; initialized to $10, counts down to 0 as they die (but changing this in mid-level changes nothing, it changes right back!)
trigger         := $00A3                        ; shadow of TRIG0 or 1 depending on which player is playing
smartbombs      := $00A5
trampoline      := $00A7                        ; indirect jmp vector
scanner_colormask:= $00A9
ship_anim_counter:= $00AA                       ; player's ship has its own animation counter
draw_ok_flag    := $00AB                        ; bit 7 set = ok to write to screen ram (set by bottom_dli_handler, cleared by top_dli_handler)
spacebar_flag   := $00AC                        ; bit 7 set = player pressed spacebar
hyperspace_flag := $00AE                        ; bit 7 set = player pressed hyperspace key
pause_flag      := $00AF                        ; 00 = playing, $80 = paused while playing, $ff = not playing (title screen or game over)
select_flag     := $00B0                        ; bit 7 set = select was pressed
sound_offset    := $00B1                        ; offset into sound_ptr list
sound_ptr       := $00B2                        ; points to a list of AUDF, AUDC values
cur_sound_tempo := $00B4                        ; speed of currently-playing event sound
sound_tempo     := $00B5                        ; play_event_sound uses this to set cur_sound_tempo
cur_sound_timer := $00B6                        ; incremented each call to update_sound. when it reaches cur_sound_tempo, we increment sound_offset
sound_priority  := $00B7                        ; priority of currently-playing event sound
tmp_hoffset_r   := $00B8
enemy_firing_freq:= $00BB                       ; starts at $3f, $1f, $0f for easy/med/hard. shifts right at start of every other level, until it reaches $03 (and stays there forever)
drone_volume    := $00BD                        ; initialized to $1f by init_drone, decrements to 0 during sound fade-out
start_flag      := $00BE                        ; bit 7 set = start was pressed
screen_ptr      := $00C0                        ; pointer to screen memory, used by print_letter, draw_glyph, draw_sprite_(left|right), etc
current_player_shot:= $00C2                     ; update_player_shots only updates one shot per call. this keeps track of which one, counts 0 4 8 $C.
ship_x_pos      := $00C3                        ; ship's visible X position on screen (not in the scanner). ranges $20 to $76
ship_y_pos      := $00C4                        ; lower = higher on the screen, $20 = top, $b4 = bottom
ship_direction  := $00C5                        ; which way the ship is facing. 1 = right, $FF (-1) = left.
random_seed     := $00C6                        ; initialized to $f3 $12 $53 by init_cart
ship_delta      := $00D5                        ; ship's movement, negative = left, 0 = stationary, positive = right. range -6 ($fa) to 6.
sprite_y        := $00DF                        ; Y position of sprite, for draw_sprite_(left|right)
last_kbcode     := $00E0                        ; KBCODE gets saved here by check_key_code
game_type       := $00E1                        ; 1-3 = 1p easy/med/hard, 4-6 = 2p e/m/h, 0 = demo
players         := $00E2                        ; 1 or 2 (1 in demo mode also)
sprite_x        := $00E3                        ; X position of sprite, for draw_sprite_(left|right)
tmp_ptr         := $00E7                        ; used to point into screen memory by draw_glyph, also used for clearing sprite memory and blowing up the planet
invuln_flag     := $00ED                        ; bit 7 set = ship collisions ignored... but also you can't clear a level. always set in demo game. temporarily set when the player's ship is exploding (to avoid further collisions killing it again while it's busy dying)
glyph_color_mask:= $00EE                        ; used by draw_glyph, $FF = color 3, all pixels 11 (like they're stored in the ROM), $55 and $AA for printing in colors 1 and 2.
ship_dead_flag  := $00EF                        ; bit 7 set = collision with something that kills us (set by ship_collision)
key_debounce_ctr:= $00F0                        ; keypresses are ignored until this counts to $10
current_player  := $00F1                        ; 1 or 2 in 2-player games, always 1 in 1-player and demo
level_jiffies_hi:= $00F6                        ; init to 0 at start of level, increments every 256 frames while game is playing
protection_flag := $00F8                        ; bit 7 set = protection check failed, game will show title screen but refuse to start
current_sprite  := $00F9                        ; 0 = human. (lower 3 bits are word index into score_points_table)
VDSLST          := $0200                        ; DLI vector
VKEYBD          := $0208                        ; === page 2 OS equates
VKEYBD_hi       := $0209
SDMCTL          := $022F
SDLSTL          := $0230                        ; dlist start, lo byte
SDLSTH          := $0231                        ; dlist start, hi byte
COLDST          := $0244
GPRIOR          := $026F
PCOLR0          := $02C0
PCOLR1          := $02C1
PCOLR2          := $02C2
PCOLR3          := $02C3
COLOR0          := $02C4
COLOR1          := $02C5
COLOR2          := $02C6
COLOR3          := $02C7
COLOR4          := $02C8
CHBAS           := $02F4
splosion_particles:= $0400                      ; page full of random garbage, generated by init_splosion, used/altered by animate_plosion
plosion_x       := $0505
plosion_y       := $0506
plosion_x_start := $0507
plosion_y_start := $0508
leading_zero_flag:= $0510                       ; bit 7 clear = skip leading zeroes in print_number. set = print leading zeroes ('01' instead of '1'
cursor_line     := $0512                        ; cursor_x times 9, scanline where next char prints (range XXX)
cur_line        := $0513                        ; current line of glyph being drawn, used by print_letter and draw_glyph
last_line       := $0514                        ; last line of glyph being drawn, used by print_letter and draw_glyph
cursor_x_tmp    := $0515
glyph_offset    := $0516                        ; offset of glyph from start of font (0, 8, 16, 24, ...), used by draw_glyph
y_stash         := $0519                        ; temp, used by print_letter and draw_glyph
player_shots_y  := $051A                        ; table of active shots, 4 entries, 4 bytes per entry: y pos, x start, x end, delta
player_shots_x_start:= $051B
player_shots_x_end:= $051C
player_shots_delta:= $051D
enemy_explosion_table:= $052B                   ; 4 bytes per entry, 32 entries
sprite_list     := $0AEB                        ; enemies, humanoids, everything alive & movable. 4 bytes per entry (XXX don't know what they mean yet)
pss_temp        := $0C4B                        ; 16 bytes, used by preshift_sprite
actor_list      := $0C6B                        ; 6 bytes/entry, 32 entries max, sprites in sprite_list also an entry here XXX
exhaust_flag    := $0D2B                        ; bit 7 set = draw rocket exhaust
vert_horiz_flag := $0D2C                        ; check_ship_move uses this, bit 0 clear = check for horizontal movement, set = vertical
inertia_counter := $0D2D                        ; XXX
horiz_acceleration:= $0D2E                      ; XXX
sp_humanoid     := $0D2F                        ; ram copies of sprites. sp_x is the original sprite. sp_x+$10, sp_x+$20, sp_x+$30 are right-shifted copies, by 1/2/3 pixels respectively
sp_lander_1     := $0D6F
sp_lander_2     := $0DAF
sp_mutant_1     := $0DEF
sp_mutant_2     := $0E2F
sp_rship_l_1    := $0E6F
sp_rship_r_1    := $0EAF
sp_rship_l_2    := $0EEF
sp_rship_r_2    := $0F2F
sp_lship_l_1    := $0F6F
sp_lship_r_1    := $0FAF
sp_lship_l_2    := $0FEF
sp_lship_r_2    := $102F
sp_bullet       := $106F
sp_bomber_1     := $10AF
sp_bomber_2     := $10EF
sp_xbomb        := $112F
sp_lflame_1     := $116F
sp_lflame_2     := $11AF
sp_rflame_1     := $11EF
sp_rflame_2     := $122F
sp_pod_1        := $126F
sp_pod_2        := $12AF
sp_swarmer      := $12EF
sp_baiter_l     := $132F
sp_baiter_r     := $136F
sp_smartbomb_1  := $13AF
sp_smartbomb_2  := $13EF
score           := $142F                        ; lsb first, binary base 100 (each byte ranges $00 to $63 (99 dec)
cursor_x        := $1439                        ; column where printchar will print next character (range 0-$27 I think)
cursor_y        := $143A                        ; row where printchar will print next character (range XXX)
p1_sav_sprite_list:= $1600
p1_sav_score    := $17C0
p1_sav_fire_freq:= $17C5
p1_sav_lives    := $17C6
p1_sav_bombs    := $17C7
p1_sav_lander_wave_count:= $17C8
p1_sav_level    := $17C9
p2_sav_sprite_list:= $1800
p2_sav_score    := $19C0
p2_sav_planet_dead:= $19C4
p2_sav_fire_freq:= $19C5
p2_sav_lives    := $19C6
p2_sav_bombs    := $19C7
p2_sav_lander_wave_count:= $19C8
p2_sav_level    := $19C9
offset_index_table:= $1A00                      ; filled with repeating pattern 00 01 02 03 00 01 02 03... basically a modulus 4 lookup
horiz_offset_table:= $1B00                      ; coarse (byte) offset for each horizontal position, the 0th thru 39th byte on a scanline
pixel_mask_table:= $1C00                        ; filled with repeating pattern c0 30 0c 03 c0 30 0c 03 ...
screen_lo_ptrs  := $1D00                        ; pointers to the start of each scanline in screen memory (lo bytes)
screen_hi_ptrs  := $1E00                        ; pointers to the start of each scanline in screen memory (hi bytes)
draw_sprite_left_copy:= $1F00                   ; self-modifying RAM copy of draw_sprite_left
draw_sprite_right_copy:= $1F80                  ; self-modifying RAM copy of draw_sprite_right
dlist_ram       := $2000                        ; 190 scanlines of GR.15 with 2 DLIs
screen_ram      := $2218                        ; 190 scanlines * 40 bytes/line = 7600 ($1db0) bytes
p1_sav_planet_dead:= $79C4
HPOSP3          := $D003                        ; === GTIA equates
HPOSM0          := $D004
HPOSM1          := $D005
HPOSM2          := $D006
HPOSM3          := $D007
SIZEP2          := $D00A
SIZEP3          := $D00B
SIZEM           := $D00C
TRIG0           := $D010
TRIG1           := $D011
COLPM0          := $D012
COLPM1          := $D013
COLPF0          := $D016
COLPF1          := $D017
COLPF2          := $D018
COLPF3          := $D019
COLBK           := $D01A
PRIOR           := $D01B
GRACTL          := $D01D
HITCLR          := $D01E
CONSOL          := $D01F
AUDF1           := $D200                        ; === POKEY equates
AUDC1           := $D201
AUDF2           := $D202
AUDC2           := $D203
AUDF3           := $D204
AUDC3           := $D205
AUDF4           := $D206
AUDC4           := $D207
AUDCTL          := $D208
KBCODE          := $D209
RANDOM          := $D20A
IRQEN           := $D20E
SKCTL           := $D20F
PORTA           := $D300                        ; === PIA equates
PORTB           := $D301
PACTL           := $D302
PBCTL           := $D303
DMACTL          := $D400                        ; === ANTIC equates
DLISTL          := $D402
DLISTH          := $D403
HSCROL          := $D404
PMBASE          := $D407
CHBASE          := $D409
WSYNC           := $D40A
VCOUNT          := $D40B
NMIEN           := $D40E
; ----------------------------------------------------------------------------
; cart_a_start points here. copy-protection setup prevents the game from starting if it's been >= 256 jiffies (~4 sec) since cold or warm start
init_cart:
        pla                                     ; 8000 68                       h
        pla                                     ; 8001 68                       h
        lsr     protection_flag                 ; 8002 46 F8                    F.
        lda     RTCLOK+1                        ; 8004 A5 13                    ..
        beq     rtclok_ok                       ; 8006 F0 03                    ..
        sec                                     ; 8008 38                       8
        ror     protection_flag                 ; 8009 66 F8                    f.
rtclok_ok:
        jsr     init_hardware                   ; 800B 20 89 B8                  ..
        jsr     init_work_ram                   ; 800E 20 68 A2                  h.
        lda     #$FF                            ; 8011 A9 FF                    ..
        sta     COLDST                          ; 8013 8D 44 02                 .D.
        lda     #$F3                            ; 8016 A9 F3                    ..
        sta     random_seed                     ; 8018 85 C6                    ..
        lda     #$12                            ; 801A A9 12                    ..
        sta     random_seed+1                   ; 801C 85 C7                    ..
        lda     #$53                            ; 801E A9 53                    .S
        sta     random_seed+2                   ; 8020 85 C8                    ..
        jsr     L9D18                           ; 8022 20 18 9D                  ..
        sec                                     ; 8025 38                       8
        ror     planet_dead_flag                ; 8026 66 A0                    f.
        jsr     clear_scanner_draw_planet_and_humans; 8028 20 5E 9E              ^.
        lsr     planet_dead_flag                ; 802B 46 A0                    F.
        lda     #$01                            ; 802D A9 01                    ..
        sta     game_type                       ; 802F 85 E1                    ..
init_title_screen:
        lda     #$08                            ; 8031 A9 08                    ..
        sta     CONSOL                          ; 8033 8D 1F D0                 ...
        lsr     $F2                             ; 8036 46 F2                    F.
        lda     #$01                            ; 8038 A9 01                    ..
        sta     current_player                  ; 803A 85 F1                    ..
        lda     #$00                            ; 803C A9 00                    ..
        sta     level                           ; 803E 85 9A                    ..
        sta     ATRACT                          ; 8040 85 4D                    .M
        lda     #$7E                            ; 8042 A9 7E                    .~
        sta     COLOR2                          ; 8044 8D C6 02                 ...
        lda     #$00                            ; 8047 A9 00                    ..
        sta     $E9                             ; 8049 85 E9                    ..
        sta     $EA                             ; 804B 85 EA                    ..
        sta     planet_dead_flag                ; 804D 85 A0                    ..
        sta     ship_delta                      ; 804F 85 D5                    ..
        lda     #$04                            ; 8051 A9 04                    ..
        sta     lives                           ; 8053 85 9E                    ..
        sta     smartbombs                      ; 8055 85 A5                    ..
        sta     p1_sav_lives                    ; 8057 8D C6 17                 ...
        sta     p1_sav_bombs                    ; 805A 8D C7 17                 ...
        sta     p2_sav_lives                    ; 805D 8D C6 19                 ...
        sta     p2_sav_bombs                    ; 8060 8D C7 19                 ...
        lda     #$FF                            ; 8063 A9 FF                    ..
        sta     pause_flag                      ; 8065 85 AF                    ..
        lda     #$00                            ; 8067 A9 00                    ..
        sta     select_flag                     ; 8069 85 B0                    ..
        sta     hyperspace_flag                 ; 806B 85 AE                    ..
        sta     start_flag                      ; 806D 85 BE                    ..
        sta     invuln_flag                     ; 806F 85 ED                    ..
        sta     ship_dead_flag                  ; 8071 85 EF                    ..
        lda     game_type                       ; 8073 A5 E1                    ..
        jmp     set_game_type                   ; 8075 4C E6 80                 L..

; ----------------------------------------------------------------------------
; play & fade the drone while we wait for the user to press select or start
title_screen_idle:
        jsr     init_drone                      ; 8078 20 79 8D                  y.
        lda     #$FF                            ; 807B A9 FF                    ..
        sta     drone_volume                    ; 807D 85 BD                    ..
        jsr     clear_screen                    ; 807F 20 A1 B8                  ..
        jsr     draw_scanner_border_and_planet  ; 8082 20 B1 9F                  ..
        lda     game_type                       ; 8085 A5 E1                    ..
        beq     tsi_text                        ; 8087 F0 06                    ..
        jsr     draw_p1_lives_and_bombs         ; 8089 20 B0 86                  ..
        jsr     draw_p2_lives_and_bombs         ; 808C 20 80 87                  ..
; play & fade the drone while we wait for the user to press select or start
tsi_text:
        jsr     draw_title_text                 ; 808F 20 59 82                  Y.
tsi_show_gt:
        jsr     show_game_type                  ; 8092 20 1F 81                  ..
tsi_wait_to_draw:
        lda     draw_ok_flag                    ; 8095 A5 AB                    ..
        bpl     tsi_wait_to_draw                ; 8097 10 FC                    ..
        clc                                     ; 8099 18                       .
; rotate colors
update_title_colors:
        lda     COLOR0                          ; 809A AD C4 02                 ...
        adc     #$10                            ; 809D 69 10                    i.
        sta     COLOR0                          ; 809F 8D C4 02                 ...
        lda     drone_volume                    ; 80A2 A5 BD                    ..
        beq     tsi_check_start                 ; 80A4 F0 11                    ..
; alter the drone sound's pitch
update_title_sfx:
        sec                                     ; 80A6 38                       8
        sbc     #$01                            ; 80A7 E9 01                    ..
        sta     drone_volume                    ; 80A9 85 BD                    ..
        lsr     a                               ; 80AB 4A                       J
        lsr     a                               ; 80AC 4A                       J
        lsr     a                               ; 80AD 4A                       J
        lsr     a                               ; 80AE 4A                       J
        ora     #$A0                            ; 80AF 09 A0                    ..
        sta     AUDC3                           ; 80B1 8D 05 D2                 ...
        sta     AUDC4                           ; 80B4 8D 07 D2                 ...
tsi_check_start:
        lda     #$FF                            ; 80B7 A9 FF                    ..
        sta     pause_flag                      ; 80B9 85 AF                    ..
        jsr     read_consol                     ; 80BB 20 A0 BA                  ..
        lda     start_flag                      ; 80BE A5 BE                    ..
        bmi     start_game                      ; 80C0 30 3E                    0>
        lda     select_flag                     ; 80C2 A5 B0                    ..
        bpl     tsi_show_gt                     ; 80C4 10 CC                    ..
        lda     #$03                            ; 80C6 A9 03                    ..
tsi_delay:
        pha                                     ; 80C8 48                       H
        lda     #$FF                            ; 80C9 A9 FF                    ..
        jsr     delay_loop                      ; 80CB 20 74 88                  t.
        pla                                     ; 80CE 68                       h
        sec                                     ; 80CF 38                       8
        sbc     #$01                            ; 80D0 E9 01                    ..
        bne     tsi_delay                       ; 80D2 D0 F4                    ..
        lda     #$00                            ; 80D4 A9 00                    ..
        sta     select_flag                     ; 80D6 85 B0                    ..
        sta     ATRACT                          ; 80D8 85 4D                    .M
        inc     game_type                       ; 80DA E6 E1                    ..
        lda     game_type                       ; 80DC A5 E1                    ..
        cmp     #$07                            ; 80DE C9 07                    ..
        bcc     set_game_type                   ; 80E0 90 04                    ..
        lda     #$00                            ; 80E2 A9 00                    ..
        sta     game_type                       ; 80E4 85 E1                    ..
set_game_type:
        tay                                     ; 80E6 A8                       .
        lda     game_type_table,y               ; 80E7 B9 F9 80                 ...
        sta     enemy_firing_freq               ; 80EA 85 BB                    ..
        lda     #$01                            ; 80EC A9 01                    ..
        sta     players                         ; 80EE 85 E2                    ..
        cpy     #$04                            ; 80F0 C0 04                    ..
        bcc     title_screen_idle               ; 80F2 90 84                    ..
        inc     players                         ; 80F4 E6 E2                    ..
        jmp     title_screen_idle               ; 80F6 4C 78 80                 Lx.

; ----------------------------------------------------------------------------
; game select table (7 entries: demo, 1p easy/med/hard, 2p easy/med/hard)
game_type_table:
        .byte   $3F,$3F,$1F,$0F,$3F,$1F,$0F     ; 80F9 3F 3F 1F 0F 3F 1F 0F     ??..?..
; ----------------------------------------------------------------------------
; ...
start_game:
        lda     #$CA                            ; 8100 A9 CA                    ..
        sta     COLOR0                          ; 8102 8D C4 02                 ...
        lda     #$00                            ; 8105 A9 00                    ..
        sta     pause_flag                      ; 8107 85 AF                    ..
        sta     select_flag                     ; 8109 85 B0                    ..
        sta     start_flag                      ; 810B 85 BE                    ..
        sta     hyperspace_flag                 ; 810D 85 AE                    ..
        sta     spacebar_flag                   ; 810F 85 AC                    ..
        sta     key_debounce_ctr                ; 8111 85 F0                    ..
        sta     last_kbcode                     ; 8113 85 E0                    ..
        bit     protection_flag                 ; 8115 24 F8                    $.
        bpl     protection_ok                   ; 8117 10 03                    ..
        jmp     init_title_screen               ; 8119 4C 31 80                 L1.

; ----------------------------------------------------------------------------
protection_ok:
        jmp     game_on                         ; 811C 4C 69 83                 Li.

; ----------------------------------------------------------------------------
; draw the text for e.g. ONE PLAYER EASY
show_game_type:
        lda     #$55                            ; 811F A9 55                    .U
        sta     glyph_color_mask                ; 8121 85 EE                    ..
        lda     game_type                       ; 8123 A5 E1                    ..
        asl     a                               ; 8125 0A                       .
        tay                                     ; 8126 A8                       .
        lda     game_type_text_ptrs,y           ; 8127 B9 48 81                 .H.
        sta     tmp_ptr                         ; 812A 85 E7                    ..
        lda     game_type_text_ptrs+1,y         ; 812C B9 49 81                 .I.
        sta     tmp_ptr+1                       ; 812F 85 E8                    ..
        lda     #$09                            ; 8131 A9 09                    ..
        sta     cursor_y                        ; 8133 8D 3A 14                 .:.
        lda     #$00                            ; 8136 A9 00                    ..
        sta     cursor_x                        ; 8138 8D 39 14                 .9.
        ldy     #$00                            ; 813B A0 00                    ..
sgt_nextchar:
        lda     (tmp_ptr),y                     ; 813D B1 E7                    ..
        beq     sgt_done                        ; 813F F0 06                    ..
        jsr     printchar                       ; 8141 20 2E 97                  ..
        iny                                     ; 8144 C8                       .
        bne     sgt_nextchar                    ; 8145 D0 F6                    ..
sgt_done:
        rts                                     ; 8147 60                       `

; ----------------------------------------------------------------------------
; the strings these point to are 37 characters long, null-terminated, ASCII with high bit set (this game was ported from the Apple II, where ASCII normally has the high bit set)
game_type_text_ptrs:
        .addr   gttxt_demo                      ; 8148 56 81                    V.
        .addr   gttxt_1p_easy                   ; 814A 7B 81                    {.
        .addr   gttxt_1p_normal                 ; 814C A0 81                    ..
        .addr   gttxt_1p_hard                   ; 814E C5 81                    ..
        .addr   gttxt_2p_easy                   ; 8150 EA 81                    ..
        .addr   gttxt_2p_normal                 ; 8152 0F 82                    ..
        .addr   gttxt_2p_hard                   ; 8154 34 82                    4.
; ----------------------------------------------------------------------------
; '   D E F E N D E R  G A M E  D E M O'
gttxt_demo:
        .byte   $A0,$A0,$A0,$C4,$A0,$C5,$A0,$C6 ; 8156 A0 A0 A0 C4 A0 C5 A0 C6  ........
        .byte   $A0,$C5,$A0,$CE,$A0,$C4,$A0,$C5 ; 815E A0 C5 A0 CE A0 C4 A0 C5  ........
        .byte   $A0,$D2,$A0,$A0,$C7,$A0,$C1,$A0 ; 8166 A0 D2 A0 A0 C7 A0 C1 A0  ........
        .byte   $CD,$A0,$C5,$A0,$A0,$C4,$A0,$C5 ; 816E CD A0 C5 A0 A0 C4 A0 C5  ........
        .byte   $A0,$CD,$A0,$CF,$00             ; 8176 A0 CD A0 CF 00           .....
; '      O N E  P L A Y E R  E A S Y   '
gttxt_1p_easy:
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$CF,$A0 ; 817B A0 A0 A0 A0 A0 A0 CF A0  ........
        .byte   $CE,$A0,$C5,$A0,$A0,$D0,$A0,$CC ; 8183 CE A0 C5 A0 A0 D0 A0 CC  ........
        .byte   $A0,$C1,$A0,$D9,$A0,$C5,$A0,$D2 ; 818B A0 C1 A0 D9 A0 C5 A0 D2  ........
        .byte   $A0,$A0,$C5,$A0,$C1,$A0,$D3,$A0 ; 8193 A0 A0 C5 A0 C1 A0 D3 A0  ........
        .byte   $D9,$A0,$A0,$A0,$00             ; 819B D9 A0 A0 A0 00           .....
; '    O N E  P L A Y E R  N O R M A L '
gttxt_1p_normal:
        .byte   $A0,$A0,$A0,$A0,$CF,$A0,$CE,$A0 ; 81A0 A0 A0 A0 A0 CF A0 CE A0  ........
        .byte   $C5,$A0,$A0,$D0,$A0,$CC,$A0,$C1 ; 81A8 C5 A0 A0 D0 A0 CC A0 C1  ........
        .byte   $A0,$D9,$A0,$C5,$A0,$D2,$A0,$A0 ; 81B0 A0 D9 A0 C5 A0 D2 A0 A0  ........
        .byte   $CE,$A0,$CF,$A0,$D2,$A0,$CD,$A0 ; 81B8 CE A0 CF A0 D2 A0 CD A0  ........
        .byte   $C1,$A0,$CC,$A0,$00             ; 81C0 C1 A0 CC A0 00           .....
; '      O N E  P L A Y E R  H A R D   '
gttxt_1p_hard:
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$CF,$A0 ; 81C5 A0 A0 A0 A0 A0 A0 CF A0  ........
        .byte   $CE,$A0,$C5,$A0,$A0,$D0,$A0,$CC ; 81CD CE A0 C5 A0 A0 D0 A0 CC  ........
        .byte   $A0,$C1,$A0,$D9,$A0,$C5,$A0,$D2 ; 81D5 A0 C1 A0 D9 A0 C5 A0 D2  ........
        .byte   $A0,$A0,$C8,$A0,$C1,$A0,$D2,$A0 ; 81DD A0 A0 C8 A0 C1 A0 D2 A0  ........
        .byte   $C4,$A0,$A0,$A0,$00             ; 81E5 C4 A0 A0 A0 00           .....
; '      T W O  P L A Y E R  E A S Y   '
gttxt_2p_easy:
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$D4,$A0 ; 81EA A0 A0 A0 A0 A0 A0 D4 A0  ........
        .byte   $D7,$A0,$CF,$A0,$A0,$D0,$A0,$CC ; 81F2 D7 A0 CF A0 A0 D0 A0 CC  ........
        .byte   $A0,$C1,$A0,$D9,$A0,$C5,$A0,$D2 ; 81FA A0 C1 A0 D9 A0 C5 A0 D2  ........
        .byte   $A0,$A0,$C5,$A0,$C1,$A0,$D3,$A0 ; 8202 A0 A0 C5 A0 C1 A0 D3 A0  ........
        .byte   $D9,$A0,$A0,$A0,$00             ; 820A D9 A0 A0 A0 00           .....
; '    T W O  P L A Y E R  N O R M A L '
gttxt_2p_normal:
        .byte   $A0,$A0,$A0,$A0,$D4,$A0,$D7,$A0 ; 820F A0 A0 A0 A0 D4 A0 D7 A0  ........
        .byte   $CF,$A0,$A0,$D0,$A0,$CC,$A0,$C1 ; 8217 CF A0 A0 D0 A0 CC A0 C1  ........
        .byte   $A0,$D9,$A0,$C5,$A0,$D2,$A0,$A0 ; 821F A0 D9 A0 C5 A0 D2 A0 A0  ........
        .byte   $CE,$A0,$CF,$A0,$D2,$A0,$CD,$A0 ; 8227 CE A0 CF A0 D2 A0 CD A0  ........
        .byte   $C1,$A0,$CC,$A0,$00             ; 822F C1 A0 CC A0 00           .....
; '      T W O  P L A Y E R  H A R D   '
gttxt_2p_hard:
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$D4,$A0 ; 8234 A0 A0 A0 A0 A0 A0 D4 A0  ........
        .byte   $D7,$A0,$CF,$A0,$A0,$D0,$A0,$CC ; 823C D7 A0 CF A0 A0 D0 A0 CC  ........
        .byte   $A0,$C1,$A0,$D9,$A0,$C5,$A0,$D2 ; 8244 A0 C1 A0 D9 A0 C5 A0 D2  ........
        .byte   $A0,$A0,$C8,$A0,$C1,$A0,$D2,$A0 ; 824C A0 A0 C8 A0 C1 A0 D2 A0  ........
        .byte   $C4,$A0,$A0,$A0,$00             ; 8254 C4 A0 A0 A0 00           .....
; ----------------------------------------------------------------------------
; draw the text for DEFENDER/SELECT GAME AND PRESS THE START BUTTON
draw_title_text:
        lda     #$06                            ; 8259 A9 06                    ..
        sta     cursor_y                        ; 825B 8D 3A 14                 .:.
        lda     #$00                            ; 825E A9 00                    ..
        sta     cursor_x                        ; 8260 8D 39 14                 .9.
        lda     #$FF                            ; 8263 A9 FF                    ..
        sta     glyph_color_mask                ; 8265 85 EE                    ..
; lda #<title_text
dtt_lo: lda     #$95                            ; 8267 A9 95                    ..
        sta     tmp_ptr                         ; 8269 85 E7                    ..
; lda #>title_text
dtt_hi: lda     #$82                            ; 826B A9 82                    ..
        sta     tmp_ptr+1                       ; 826D 85 E8                    ..
        ldy     #$00                            ; 826F A0 00                    ..
dtt_loop:
        lda     (tmp_ptr),y                     ; 8271 B1 E7                    ..
        beq     dtt_done                        ; 8273 F0 1F                    ..
        cmp     #$F0                            ; 8275 C9 F0                    ..
        bcc     dtt_print                       ; 8277 90 0F                    ..
; multicolor support. bytes with $Fn in the message set the color mask to nn.
dtt_color:
        and     #$0F                            ; 8279 29 0F                    ).
        sta     sprite_x                        ; 827B 85 E3                    ..
        asl     a                               ; 827D 0A                       .
        asl     a                               ; 827E 0A                       .
        asl     a                               ; 827F 0A                       .
        asl     a                               ; 8280 0A                       .
        ora     sprite_x                        ; 8281 05 E3                    ..
        sta     glyph_color_mask                ; 8283 85 EE                    ..
        jmp     dtt_inc_ptr                     ; 8285 4C 8B 82                 L..

; ----------------------------------------------------------------------------
dtt_print:
        jsr     printchar                       ; 8288 20 2E 97                  ..
dtt_inc_ptr:
        inc     tmp_ptr                         ; 828B E6 E7                    ..
        bne     dtt_loop                        ; 828D D0 E2                    ..
        inc     tmp_ptr+1                       ; 828F E6 E8                    ..
        jmp     dtt_loop                        ; 8291 4C 71 82                 Lq.

; ----------------------------------------------------------------------------
dtt_done:
        rts                                     ; 8294 60                       `

; ----------------------------------------------------------------------------
; cF, c5 are color codes. 'cF             D E F E N D E RnlnlnlnlnlnlcF S E L E C T  G A M E  A N D  P R E S Snlnl      T H E  S T A R T  B U T T O Nnlnlnlnlc5         c)  1 9 8 2  A T A R I'
title_text:
        .byte   $FF,$A0,$A0,$A0,$A0,$A0,$A0,$A0 ; 8295 FF A0 A0 A0 A0 A0 A0 A0  ........
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$C4,$A0 ; 829D A0 A0 A0 A0 A0 A0 C4 A0  ........
        .byte   $C5,$A0,$C6,$A0,$C5,$A0,$CE,$A0 ; 82A5 C5 A0 C6 A0 C5 A0 CE A0  ........
        .byte   $C4,$A0,$C5,$A0,$D2,$8D,$8D,$8D ; 82AD C4 A0 C5 A0 D2 8D 8D 8D  ........
        .byte   $8D,$8D,$8D,$FF,$A0,$D3,$A0,$C5 ; 82B5 8D 8D 8D FF A0 D3 A0 C5  ........
        .byte   $A0,$CC,$A0,$C5,$A0,$C3,$A0,$D4 ; 82BD A0 CC A0 C5 A0 C3 A0 D4  ........
        .byte   $A0,$A0,$C7,$A0,$C1,$A0,$CD,$A0 ; 82C5 A0 A0 C7 A0 C1 A0 CD A0  ........
        .byte   $C5,$A0,$A0,$C1,$A0,$CE,$A0,$C4 ; 82CD C5 A0 A0 C1 A0 CE A0 C4  ........
        .byte   $A0,$A0,$D0,$A0,$D2,$A0,$C5,$A0 ; 82D5 A0 A0 D0 A0 D2 A0 C5 A0  ........
        .byte   $D3,$A0,$D3,$8D,$8D,$A0,$A0,$A0 ; 82DD D3 A0 D3 8D 8D A0 A0 A0  ........
        .byte   $A0,$A0,$A0,$D4,$A0,$C8,$A0,$C5 ; 82E5 A0 A0 A0 D4 A0 C8 A0 C5  ........
        .byte   $A0,$A0,$D3,$A0,$D4,$A0,$C1,$A0 ; 82ED A0 A0 D3 A0 D4 A0 C1 A0  ........
        .byte   $D2,$A0,$D4,$A0,$A0,$C2,$A0,$D5 ; 82F5 D2 A0 D4 A0 A0 C2 A0 D5  ........
        .byte   $A0,$D4,$A0,$D4,$A0,$CF,$A0,$CE ; 82FD A0 D4 A0 D4 A0 CF A0 CE  ........
        .byte   $8D,$8D,$8D,$8D,$F5,$A0,$A0,$A0 ; 8305 8D 8D 8D 8D F5 A0 A0 A0  ........
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$C0,$A0 ; 830D A0 A0 A0 A0 A0 A0 C0 A0  ........
        .byte   $A0,$B1,$A0,$B9,$A0,$B8,$A0,$B2 ; 8315 A0 B1 A0 B9 A0 B8 A0 B2  ........
        .byte   $A0,$A0,$C1,$A0,$D4,$A0,$C1,$A0 ; 831D A0 A0 C1 A0 D4 A0 C1 A0  ........
        .byte   $D2,$A0,$C9,$00                 ; 8325 D2 A0 C9 00              ....
; is this used at all?
table_8329:
        .byte   $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF ; 8329 FF FF FF FF FF FF FF FF  ........
        .byte   $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF ; 8331 FF FF FF FF FF FF FF FF  ........
        .byte   $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF ; 8339 FF FF FF FF FF FF FF FF  ........
        .byte   $04,$FF,$03,$06,$FF,$05,$02,$01 ; 8341 04 FF 03 06 FF 05 02 01  ........
        .byte   $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF ; 8349 FF FF FF FF FF FF FF FF  ........
        .byte   $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF ; 8351 FF FF FF FF FF FF FF FF  ........
        .byte   $FF,$FF,$00,$FF,$FF,$FF,$FF,$FF ; 8359 FF FF 00 FF FF FF FF FF  ........
        .byte   $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF ; 8361 FF FF FF FF FF FF FF FF  ........
; ----------------------------------------------------------------------------
; called when start button is pressed from title screen or pause mode
game_on:jsr     init_drone                      ; 8369 20 79 8D                  y.
        lda     #$FF                            ; 836C A9 FF                    ..
        sta     scanner_colormask               ; 836E 85 A9                    ..
        lda     #$00                            ; 8370 A9 00                    ..
        sta     score                           ; 8372 8D 2F 14                 ./.
        sta     score+1                         ; 8375 8D 30 14                 .0.
        sta     score+2                         ; 8378 8D 31 14                 .1.
        sta     score+3                         ; 837B 8D 32 14                 .2.
        lda     #$03                            ; 837E A9 03                    ..
        sta     lives                           ; 8380 85 9E                    ..
        sta     smartbombs                      ; 8382 85 A5                    ..
        lda     #$07                            ; 8384 A9 07                    ..
        sta     horiz_acceleration              ; 8386 8D 2E 0D                 ...
        lda     #$00                            ; 8389 A9 00                    ..
        sta     inertia_counter                 ; 838B 8D 2D 0D                 .-.
        sta     exhaust_flag                    ; 838E 8D 2B 0D                 .+.
        ldy     game_type                       ; 8391 A4 E1                    ..
        lda     game_type_table,y               ; 8393 B9 F9 80                 ...
        sta     enemy_firing_freq               ; 8396 85 BB                    ..
        jsr     LA817                           ; 8398 20 17 A8                  ..
        lda     $D7                             ; 839B A5 D7                    ..
        sta     $FE                             ; 839D 85 FE                    ..
        lda     $D8                             ; 839F A5 D8                    ..
        sta     $FF                             ; 83A1 85 FF                    ..
        jsr     init_work_ram                   ; 83A3 20 68 A2                  h.
        jsr     LAE17                           ; 83A6 20 17 AE                  ..
        lda     #$00                            ; 83A9 A9 00                    ..
        sta     planet_dead_flag                ; 83AB 85 A0                    ..
        lda     #$00                            ; 83AD A9 00                    ..
        sta     level                           ; 83AF 85 9A                    ..
        sta     last_kbcode                     ; 83B1 85 E0                    ..
        jsr     level_initial_spawn             ; 83B3 20 55 AE                  U.
        jsr     save_p1_state                   ; 83B6 20 B9 89                  ..
        jsr     save_p2_state                   ; 83B9 20 0D 8A                  ..
        lda     #$01                            ; 83BC A9 01                    ..
        sta     current_player                  ; 83BE 85 F1                    ..
        lda     #$FF                            ; 83C0 A9 FF                    ..
        sta     $F4                             ; 83C2 85 F4                    ..
        lsr     $F7                             ; 83C4 46 F7                    F.
        jmp     clear_enemy_explosions          ; 83C6 4C 5B 84                 L[.

; ----------------------------------------------------------------------------
; notice the check against $64? that's why we get stuck on level 99 over & over again
next_level:
        inc     level                           ; 83C9 E6 9A                    ..
; this branch should never be taken (means level was $FF, but it's clamped to $63 below)
nl_wtf: beq     level_cleared                   ; 83CB F0 5A                    .Z
        lda     level                           ; 83CD A5 9A                    ..
        cmp     #$64                            ; 83CF C9 64                    .d
        bcc     level_ok                        ; 83D1 90 04                    ..
        lda     #$63                            ; 83D3 A9 63                    .c
        sta     level                           ; 83D5 85 9A                    ..
; ramp up the speed on odd-numbered levels
level_ok:
        lda     level                           ; 83D7 A5 9A                    ..
        and     #$01                            ; 83D9 29 01                    ).
        bne     nl_drone                        ; 83DB D0 0D                    ..
        lda     enemy_firing_freq               ; 83DD A5 BB                    ..
        lsr     a                               ; 83DF 4A                       J
        sta     enemy_firing_freq               ; 83E0 85 BB                    ..
        cmp     #$03                            ; 83E2 C9 03                    ..
        bcs     nl_drone                        ; 83E4 B0 04                    ..
        lda     #$03                            ; 83E6 A9 03                    ..
        sta     enemy_firing_freq               ; 83E8 85 BB                    ..
nl_drone:
        jsr     init_drone                      ; 83EA 20 79 8D                  y.
        jsr     clear_screen                    ; 83ED 20 A1 B8                  ..
        jsr     clear_scanner_draw_planet_and_humans; 83F0 20 5E 9E              ^.
        jsr     draw_scanner_border_and_planet  ; 83F3 20 B1 9F                  ..
        lda     #$10                            ; 83F6 A9 10                    ..
nl_next_stars:
        pha                                     ; 83F8 48                       H
        jsr     animate_starfield               ; 83F9 20 32 A8                  2.
        pla                                     ; 83FC 68                       h
        sec                                     ; 83FD 38                       8
        sbc     #$01                            ; 83FE E9 01                    ..
        bne     nl_next_stars                   ; 8400 D0 F6                    ..
        jsr     print_end_level_msg             ; 8402 20 42 96                  B.
        jsr     draw_scores                     ; 8405 20 42 94                  B.
        inc     lives                           ; 8408 E6 9E                    ..
        jsr     draw_p1_lives_and_bombs         ; 840A 20 B0 86                  ..
        dec     lives                           ; 840D C6 9E                    ..
        jsr     draw_p2_lives_and_bombs         ; 840F 20 80 87                  ..
        lda     #$1E                            ; 8412 A9 1E                    ..
nl_delay:
        pha                                     ; 8414 48                       H
        lda     #$FF                            ; 8415 A9 FF                    ..
        jsr     delay_loop                      ; 8417 20 74 88                  t.
        pla                                     ; 841A 68                       h
        sec                                     ; 841B 38                       8
        sbc     #$01                            ; 841C E9 01                    ..
        bne     nl_delay                        ; 841E D0 F4                    ..
        lda     lives                           ; 8420 A5 9E                    ..
        bne     level_cleared                   ; 8422 D0 03                    ..
        jmp     out_of_lives                    ; 8424 4C 0E B7                 L..

; ----------------------------------------------------------------------------
; decide whether or not to resurrect dead humans
level_cleared:
        lda     level                           ; 8427 A5 9A                    ..
        clc                                     ; 8429 18                       .
        adc     #$01                            ; 842A 69 01                    i.
div_5_loop:
        sec                                     ; 842C 38                       8
        sbc     #$05                            ; 842D E9 05                    ..
        bcs     div_5_loop                      ; 842F B0 FB                    ..
        adc     #$05                            ; 8431 69 05                    i.
        bne     dont_repopulate                 ; 8433 D0 0A                    ..
        jsr     init_work_ram                   ; 8435 20 68 A2                  h.
        jsr     LAE17                           ; 8438 20 17 AE                  ..
        lda     #$00                            ; 843B A9 00                    ..
        sta     planet_dead_flag                ; 843D 85 A0                    ..
dont_repopulate:
        jsr     level_initial_spawn             ; 843F 20 55 AE                  U.
        lda     #$00                            ; 8442 A9 00                    ..
        sta     level_jiffies_lo                ; 8444 85 87                    ..
        sta     $95                             ; 8446 85 95                    ..
        lda     #$FC                            ; 8448 A9 FC                    ..
        sta     $99                             ; 844A 85 99                    ..
        sta     current_player_shot             ; 844C 85 C2                    ..
        sta     $CC                             ; 844E 85 CC                    ..
        sta     $98                             ; 8450 85 98                    ..
        sta     $A6                             ; 8452 85 A6                    ..
        bit     $F7                             ; 8454 24 F7                    $.
        bpl     clear_enemy_explosions          ; 8456 10 03                    ..
        jmp     LB6D1                           ; 8458 4C D1 B6                 L..

; ----------------------------------------------------------------------------
clear_enemy_explosions:
        ldy     #$00                            ; 845B A0 00                    ..
        lda     #$00                            ; 845D A9 00                    ..
cex_loop:
        sta     enemy_explosion_table,y         ; 845F 99 2B 05                 .+.
        iny                                     ; 8462 C8                       .
        bpl     cex_loop                        ; 8463 10 FA                    ..
; clean up game state, show prompt if in 2p mode
prep_next_level:
        jsr     clear_screen                    ; 8465 20 A1 B8                  ..
        lda     #$00                            ; 8468 A9 00                    ..
        sta     $A4                             ; 846A 85 A4                    ..
        lda     TRIG0                           ; 846C AD 10 D0                 ...
        ldy     current_player                  ; 846F A4 F1                    ..
        cpy     #$02                            ; 8471 C0 02                    ..
        bne     pnl_store_trig                  ; 8473 D0 03                    ..
        lda     TRIG1                           ; 8475 AD 11 D0                 ...
; store either TRIG0 or TRIG1
pnl_store_trig:
        sta     trigger                         ; 8478 85 A3                    ..
        lda     #$00                            ; 847A A9 00                    ..
        sta     ship_delta                      ; 847C 85 D5                    ..
        sta     select_flag                     ; 847E 85 B0                    ..
        sta     hyperspace_flag                 ; 8480 85 AE                    ..
        sta     spacebar_flag                   ; 8482 85 AC                    ..
        sta     start_flag                      ; 8484 85 BE                    ..
        sta     pause_flag                      ; 8486 85 AF                    ..
        sta     key_debounce_ctr                ; 8488 85 F0                    ..
        lda     #$50                            ; 848A A9 50                    .P
        sta     ship_x_pos                      ; 848C 85 C3                    ..
        lda     #$01                            ; 848E A9 01                    ..
        sta     ship_direction                  ; 8490 85 C5                    ..
        lda     #$78                            ; 8492 A9 78                    .x
        sta     ship_y_pos                      ; 8494 85 C4                    ..
        ldy     #$00                            ; 8496 A0 00                    ..
        lda     #$00                            ; 8498 A9 00                    ..
pnl_clear_player_shots:
        sta     player_shots_y,y                ; 849A 99 1A 05                 ...
        iny                                     ; 849D C8                       .
        cpy     #$10                            ; 849E C0 10                    ..
        bcc     pnl_clear_player_shots          ; 84A0 90 F8                    ..
        jsr     init_drone                      ; 84A2 20 79 8D                  y.
        lda     #$7E                            ; 84A5 A9 7E                    .~
        sta     COLOR2                          ; 84A7 8D C6 02                 ...
        lda     #$FF                            ; 84AA A9 FF                    ..
        sta     $D4                             ; 84AC 85 D4                    ..
        lda     #$00                            ; 84AE A9 00                    ..
        sta     ship_move_delay                 ; 84B0 85 93                    ..
        lda     #$00                            ; 84B2 A9 00                    ..
        sta     ship_dead_flag                  ; 84B4 85 EF                    ..
        sta     level_jiffies_hi                ; 84B6 85 F6                    ..
        lda     #$00                            ; 84B8 A9 00                    ..
        sta     inertia_counter                 ; 84BA 8D 2D 0D                 .-.
        jsr     clear_scanner_draw_planet_and_humans; 84BD 20 5E 9E              ^.
        jsr     draw_scanner_border_and_planet  ; 84C0 20 B1 9F                  ..
        lsr     $AD                             ; 84C3 46 AD                    F.
        jsr     draw_scores                     ; 84C5 20 42 94                  B.
        sec                                     ; 84C8 38                       8
        ror     $AD                             ; 84C9 66 AD                    f.
        jsr     draw_p1_lives_and_bombs         ; 84CB 20 B0 86                  ..
        jsr     draw_p2_lives_and_bombs         ; 84CE 20 80 87                  ..
        lda     players                         ; 84D1 A5 E2                    ..
        cmp     #$01                            ; 84D3 C9 01                    ..
        beq     prompt_done                     ; 84D5 F0 28                    .(
        lda     $F4                             ; 84D7 A5 F4                    ..
        cmp     current_player                  ; 84D9 C5 F1                    ..
        beq     prompt_done                     ; 84DB F0 22                    ."
        lda     current_player                  ; 84DD A5 F1                    ..
        sta     $F4                             ; 84DF 85 F4                    ..
        cmp     #$01                            ; 84E1 C9 01                    ..
        beq     p1_ok                           ; 84E3 F0 06                    ..
        jsr     print_p2_text                   ; 84E5 20 3E 8B                  >.
        jmp     prompt_screen_delay             ; 84E8 4C EE 84                 L..

; ----------------------------------------------------------------------------
p1_ok:  jsr     print_p1_text                   ; 84EB 20 09 8B                  ..
; wait a while to let the next player get ready
prompt_screen_delay:
        lda     #$19                            ; 84EE A9 19                    ..
psd_loop:
        pha                                     ; 84F0 48                       H
        lda     #$FF                            ; 84F1 A9 FF                    ..
        jsr     delay_loop                      ; 84F3 20 74 88                  t.
        pla                                     ; 84F6 68                       h
        sec                                     ; 84F7 38                       8
        sbc     #$01                            ; 84F8 E9 01                    ..
        bne     psd_loop                        ; 84FA D0 F4                    ..
        jsr     clear_prompt_text               ; 84FC 20 73 8B                  s.
; either the prompt screen is finished, or we were in single-player mode & didn't need it
prompt_done:
        lda     #$00                            ; 84FF A9 00                    ..
        sta     ATRACT                          ; 8501 85 4D                    .M
; handle start/select keys during gameplay (ignore if not paused)
check_consol:
        jsr     read_consol                     ; 8503 20 A0 BA                  ..
        bit     select_flag                     ; 8506 24 B0                    $.
        bpl     cc_chk_start                    ; 8508 10 07                    ..
        bit     pause_flag                      ; 850A 24 AF                    $.
        bpl     check_paused                    ; 850C 10 1C                    ..
        jmp     init_title_screen               ; 850E 4C 31 80                 L1.

; ----------------------------------------------------------------------------
cc_chk_start:
        bit     start_flag                      ; 8511 24 BE                    $.
        bpl     check_paused                    ; 8513 10 15                    ..
        bit     pause_flag                      ; 8515 24 AF                    $.
        bpl     check_paused                    ; 8517 10 11                    ..
        jmp     game_on                         ; 8519 4C 69 83                 Li.

; ----------------------------------------------------------------------------
; in demo mode, pressing any key returns to the title screen
cc_chk_keyboard:
        lda     game_type                       ; 851C A5 E1                    ..
        bne     check_paused                    ; 851E D0 0A                    ..
        jsr     draw_demo_text                  ; 8520 20 5C 89                  \.
        lda     last_kbcode                     ; 8523 A5 E0                    ..
        beq     check_paused                    ; 8525 F0 03                    ..
        jmp     init_title_screen               ; 8527 4C 31 80                 L1.

; ----------------------------------------------------------------------------
check_paused:
        bit     pause_flag                      ; 852A 24 AF                    $.
        bmi     check_consol                    ; 852C 30 D5                    0.
        inc     $D4                             ; 852E E6 D4                    ..
        lda     $D4                             ; 8530 A5 D4                    ..
        and     #$3F                            ; 8532 29 3F                    )?
        bne     L8558                           ; 8534 D0 22                    ."
        jsr     clear_scanner_draw_planet_and_humans; 8536 20 5E 9E              ^.
        jsr     smartbomb_check                 ; 8539 20 8A 8B                  ..
        jsr     LAC18                           ; 853C 20 18 AC                  ..
wait_draw_ok:
        bit     draw_ok_flag                    ; 853F 24 AB                    $.
        bpl     wait_draw_ok                    ; 8541 10 FC                    ..
        jsr     LA4CC                           ; 8543 20 CC A4                  ..
        inc     level_jiffies_lo                ; 8546 E6 87                    ..
        bne     check_spawn                     ; 8548 D0 02                    ..
        inc     level_jiffies_hi                ; 854A E6 F6                    ..
; see if it's time to spawn a lander wave or a baiter yet
check_spawn:
        lda     level_jiffies_lo                ; 854C A5 87                    ..
        and     #$3F                            ; 854E 29 3F                    )?
        bne     L8558                           ; 8550 D0 06                    ..
        jsr     spawn_lander_wave               ; 8552 20 98 AE                  ..
        jsr     baiter_check                    ; 8555 20 7B BB                  {.
L8558:  lda     $D4                             ; 8558 A5 D4                    ..
        clc                                     ; 855A 18                       .
        adc     #$20                            ; 855B 69 20                    i 
        bne     L8582                           ; 855D D0 23                    .#
        jsr     draw_scanner_border_and_planet  ; 855F 20 B1 9F                  ..
        lda     drone_volume                    ; 8562 A5 BD                    ..
        lsr     a                               ; 8564 4A                       J
        sta     drone_volume                    ; 8565 85 BD                    ..
        ora     #$A0                            ; 8567 09 A0                    ..
        sta     AUDC3                           ; 8569 8D 05 D2                 ...
        sta     AUDC4                           ; 856C 8D 07 D2                 ...
        bit     $AD                             ; 856F 24 AD                    $.
        bpl     L857F                           ; 8571 10 0C                    ..
        lda     level_jiffies_lo                ; 8573 A5 87                    ..
        and     #$08                            ; 8575 29 08                    ).
        bne     L857F                           ; 8577 D0 06                    ..
        jsr     clear_score                     ; 8579 20 BC 93                  ..
        jmp     L8582                           ; 857C 4C 82 85                 L..

; ----------------------------------------------------------------------------
L857F:  jsr     draw_scores                     ; 857F 20 42 94                  B.
L8582:  lda     $D4                             ; 8582 A5 D4                    ..
        and     #$07                            ; 8584 29 07                    ).
        bne     L858B                           ; 8586 D0 03                    ..
        jsr     animate_starfield               ; 8588 20 32 A8                  2.
L858B:  lda     $D4                             ; 858B A5 D4                    ..
        clc                                     ; 858D 18                       .
        adc     #$B3                            ; 858E 69 B3                    i.
        bne     L8595                           ; 8590 D0 03                    ..
        jsr     draw_p2_lives_and_bombs         ; 8592 20 80 87                  ..
L8595:  lda     $D4                             ; 8595 A5 D4                    ..
        clc                                     ; 8597 18                       .
        adc     #$A0                            ; 8598 69 A0                    i.
        bne     L859F                           ; 859A D0 03                    ..
        jsr     draw_p1_lives_and_bombs         ; 859C 20 B0 86                  ..
L859F:  lda     $D4                             ; 859F A5 D4                    ..
        adc     #$40                            ; 85A1 69 40                    i@
        and     #$3F                            ; 85A3 29 3F                    )?
        bne     L85AA                           ; 85A5 D0 03                    ..
        jsr     check_hyperspace                ; 85A7 20 81 88                  ..
L85AA:  jsr     update_player_shots             ; 85AA 20 17 9A                  ..
        jsr     start_explosion                 ; 85AD 20 1A 9C                  ..
        lda     $D4                             ; 85B0 A5 D4                    ..
        and     #$07                            ; 85B2 29 07                    ).
        beq     L85B9                           ; 85B4 F0 03                    ..
        jmp     cc_chk_keyboard                 ; 85B6 4C 1C 85                 L..

; ----------------------------------------------------------------------------
L85B9:  jsr     erase_scanner_ship              ; 85B9 20 0C A2                  ..
        jsr     erase_ship                      ; 85BC 20 88 B5                  ..
        jsr     erase_exhaust                   ; 85BF 20 62 99                  b.
        lda     game_type                       ; 85C2 A5 E1                    ..
        bne     move_ship                       ; 85C4 D0 03                    ..
        jmp     demo_logic                      ; 85C6 4C BD 88                 L..

; ----------------------------------------------------------------------------
; only in non-demo game
move_ship:
        lda     ship_move_delay                 ; 85C9 A5 93                    ..
        and     #$03                            ; 85CB 29 03                    ).
        beq     L85D2                           ; 85CD F0 03                    ..
        jsr     inertia_logic                   ; 85CF 20 81 86                  ..
L85D2:  inc     ship_move_delay                 ; 85D2 E6 93                    ..
        lda     ship_move_delay                 ; 85D4 A5 93                    ..
        and     #$03                            ; 85D6 29 03                    ).
        beq     L85DF                           ; 85D8 F0 05                    ..
        jsr     check_ship_move                 ; 85DA 20 EE AC                  ..
        bcc     L85F3                           ; 85DD 90 14                    ..
L85DF:  lda     TRIG0                           ; 85DF AD 10 D0                 ...
        ldy     current_player                  ; 85E2 A4 F1                    ..
        cpy     #$02                            ; 85E4 C0 02                    ..
        bne     L85EB                           ; 85E6 D0 03                    ..
        lda     TRIG1                           ; 85E8 AD 11 D0                 ...
L85EB:  eor     trigger                         ; 85EB 45 A3                    E.
        and     #$01                            ; 85ED 29 01                    ).
        bne     read_trigger                    ; 85EF D0 2B                    .+
        beq     L8603                           ; 85F1 F0 10                    ..
L85F3:  cmp     #$88                            ; 85F3 C9 88                    ..
        beq     L8670                           ; 85F5 F0 79                    .y
        cmp     #$95                            ; 85F7 C9 95                    ..
        beq     L8677                           ; 85F9 F0 7C                    .|
        cmp     #$C1                            ; 85FB C9 C1                    ..
        beq     L8630                           ; 85FD F0 31                    .1
        cmp     #$DA                            ; 85FF C9 DA                    ..
        beq     L8650                           ; 8601 F0 4D                    .M
L8603:  clc                                     ; 8603 18                       .
        lda     ship_x_pos                      ; 8604 A5 C3                    ..
        adc     $89                             ; 8606 65 89                    e.
        sta     $91                             ; 8608 85 91                    ..
        lda     $8A                             ; 860A A5 8A                    ..
        adc     #$00                            ; 860C 69 00                    i.
        sta     $92                             ; 860E 85 92                    ..
        jsr     draw_ship                       ; 8610 20 A1 B5                  ..
        jsr     ship_exhaust                    ; 8613 20 86 99                  ..
        jsr     draw_scanner_ship               ; 8616 20 93 A1                  ..
        jmp     cc_chk_keyboard                 ; 8619 4C 1C 85                 L..

; ----------------------------------------------------------------------------
; TRIG0 or 1 depending on which player is playing
read_trigger:
        lda     TRIG0                           ; 861C AD 10 D0                 ...
        ldy     current_player                  ; 861F A4 F1                    ..
        cpy     #$02                            ; 8621 C0 02                    ..
        bne     store_trigger                   ; 8623 D0 03                    ..
        lda     TRIG1                           ; 8625 AD 11 D0                 ...
store_trigger:
        sta     trigger                         ; 8628 85 A3                    ..
        jsr     handle_trigger                  ; 862A 20 D0 99                  ..
        jmp     L8603                           ; 862D 4C 03 86                 L..

; ----------------------------------------------------------------------------
L8630:  lda     #$00                            ; 8630 A9 00                    ..
        sta     $EA                             ; 8632 85 EA                    ..
        inc     $E9                             ; 8634 E6 E9                    ..
        lda     $E9                             ; 8636 A5 E9                    ..
        cmp     #$03                            ; 8638 C9 03                    ..
        bcc     L863E                           ; 863A 90 02                    ..
        dec     $E9                             ; 863C C6 E9                    ..
L863E:  sec                                     ; 863E 38                       8
        lda     ship_y_pos                      ; 863F A5 C4                    ..
        sbc     $E9                             ; 8641 E5 E9                    ..
        sta     ship_y_pos                      ; 8643 85 C4                    ..
        cmp     #$20                            ; 8645 C9 20                    . 
        bcs     L8603                           ; 8647 B0 BA                    ..
        lda     #$20                            ; 8649 A9 20                    . 
        sta     ship_y_pos                      ; 864B 85 C4                    ..
        jmp     L8603                           ; 864D 4C 03 86                 L..

; ----------------------------------------------------------------------------
L8650:  lda     #$00                            ; 8650 A9 00                    ..
        sta     $E9                             ; 8652 85 E9                    ..
        inc     $EA                             ; 8654 E6 EA                    ..
        lda     $EA                             ; 8656 A5 EA                    ..
        cmp     #$03                            ; 8658 C9 03                    ..
        bcc     L865E                           ; 865A 90 02                    ..
        dec     $EA                             ; 865C C6 EA                    ..
L865E:  clc                                     ; 865E 18                       .
        lda     ship_y_pos                      ; 865F A5 C4                    ..
        adc     $EA                             ; 8661 65 EA                    e.
        sta     ship_y_pos                      ; 8663 85 C4                    ..
        cmp     #$B4                            ; 8665 C9 B4                    ..
        bcc     L8603                           ; 8667 90 9A                    ..
        lda     #$B4                            ; 8669 A9 B4                    ..
        sta     ship_y_pos                      ; 866B 85 C4                    ..
        jmp     L8603                           ; 866D 4C 03 86                 L..

; ----------------------------------------------------------------------------
L8670:  lda     #$FF                            ; 8670 A9 FF                    ..
        sta     ship_direction                  ; 8672 85 C5                    ..
        jmp     L867B                           ; 8674 4C 7B 86                 L{.

; ----------------------------------------------------------------------------
L8677:  lda     #$01                            ; 8677 A9 01                    ..
        sta     ship_direction                  ; 8679 85 C5                    ..
L867B:  jmp     L8603                           ; 867B 4C 03 86                 L..

; ----------------------------------------------------------------------------
        jmp     L8603                           ; 867E 4C 03 86                 L..

; ----------------------------------------------------------------------------
; XXX not fully understood, stubbing this out makes the ship turn on a dime
inertia_logic:
        lda     ship_direction                  ; 8681 A5 C5                    ..
        bmi     L86A5                           ; 8683 30 20                    0 
        lda     ship_x_pos                      ; 8685 A5 C3                    ..
        cmp     #$20                            ; 8687 C9 20                    . 
        beq     L86AF                           ; 8689 F0 24                    .$
        bcc     L8699                           ; 868B 90 0C                    ..
L868D:  dec     ship_x_pos                      ; 868D C6 C3                    ..
        clc                                     ; 868F 18                       .
        lda     ship_delta                      ; 8690 A5 D5                    ..
        adc     #$03                            ; 8692 69 03                    i.
        sta     ship_delta                      ; 8694 85 D5                    ..
        jmp     L86AF                           ; 8696 4C AF 86                 L..

; ----------------------------------------------------------------------------
L8699:  inc     ship_x_pos                      ; 8699 E6 C3                    ..
        sec                                     ; 869B 38                       8
        lda     ship_delta                      ; 869C A5 D5                    ..
        sbc     #$03                            ; 869E E9 03                    ..
        sta     ship_delta                      ; 86A0 85 D5                    ..
        jmp     L86AF                           ; 86A2 4C AF 86                 L..

; ----------------------------------------------------------------------------
L86A5:  lda     ship_x_pos                      ; 86A5 A5 C3                    ..
        cmp     #$76                            ; 86A7 C9 76                    .v
        beq     L86AF                           ; 86A9 F0 04                    ..
        bcc     L8699                           ; 86AB 90 EC                    ..
        bcs     L868D                           ; 86AD B0 DE                    ..
L86AF:  rts                                     ; 86AF 60                       `

; ----------------------------------------------------------------------------
; update HUD
draw_p1_lives_and_bombs:
        lda     animation_counter               ; 86B0 A5 85                    ..
        pha                                     ; 86B2 48                       H
        inc     ship_anim_counter               ; 86B3 E6 AA                    ..
        lda     ship_anim_counter               ; 86B5 A5 AA                    ..
        sta     animation_counter               ; 86B7 85 85                    ..
        lda     ship_x_pos                      ; 86B9 A5 C3                    ..
        pha                                     ; 86BB 48                       H
        lda     ship_y_pos                      ; 86BC A5 C4                    ..
        pha                                     ; 86BE 48                       H
        lda     ship_direction                  ; 86BF A5 C5                    ..
        pha                                     ; 86C1 48                       H
        lda     #$00                            ; 86C2 A9 00                    ..
        sta     ship_direction                  ; 86C4 85 C5                    ..
        lda     current_player                  ; 86C6 A5 F1                    ..
        cmp     #$02                            ; 86C8 C9 02                    ..
        bne     L86D0                           ; 86CA D0 04                    ..
        lda     #$FF                            ; 86CC A9 FF                    ..
        sta     ship_direction                  ; 86CE 85 C5                    ..
L86D0:  lda     lives                           ; 86D0 A5 9E                    ..
        cmp     #$02                            ; 86D2 C9 02                    ..
        beq     L870C                           ; 86D4 F0 36                    .6
        bcc     L8724                           ; 86D6 90 4C                    .L
        cmp     #$03                            ; 86D8 C9 03                    ..
        beq     L86F4                           ; 86DA F0 18                    ..
        lda     #$1C                            ; 86DC A9 1C                    ..
        sta     ship_x_pos                      ; 86DE 85 C3                    ..
        lda     current_player                  ; 86E0 A5 F1                    ..
        cmp     #$01                            ; 86E2 C9 01                    ..
        beq     L86EA                           ; 86E4 F0 04                    ..
        lda     #$96                            ; 86E6 A9 96                    ..
        sta     ship_x_pos                      ; 86E8 85 C3                    ..
L86EA:  lda     #$00                            ; 86EA A9 00                    ..
        sta     ship_y_pos                      ; 86EC 85 C4                    ..
        jsr     erase_ship                      ; 86EE 20 88 B5                  ..
        jsr     draw_ship                       ; 86F1 20 A1 B5                  ..
L86F4:  lda     #$10                            ; 86F4 A9 10                    ..
        sta     ship_x_pos                      ; 86F6 85 C3                    ..
        lda     current_player                  ; 86F8 A5 F1                    ..
        cmp     #$01                            ; 86FA C9 01                    ..
        beq     L8702                           ; 86FC F0 04                    ..
        lda     #$8A                            ; 86FE A9 8A                    ..
        sta     ship_x_pos                      ; 8700 85 C3                    ..
L8702:  lda     #$00                            ; 8702 A9 00                    ..
        sta     ship_y_pos                      ; 8704 85 C4                    ..
        jsr     erase_ship                      ; 8706 20 88 B5                  ..
        jsr     draw_ship                       ; 8709 20 A1 B5                  ..
L870C:  lda     #$04                            ; 870C A9 04                    ..
        sta     ship_x_pos                      ; 870E 85 C3                    ..
        lda     current_player                  ; 8710 A5 F1                    ..
        cmp     #$01                            ; 8712 C9 01                    ..
        beq     L871A                           ; 8714 F0 04                    ..
        lda     #$7E                            ; 8716 A9 7E                    .~
        sta     ship_x_pos                      ; 8718 85 C3                    ..
L871A:  lda     #$00                            ; 871A A9 00                    ..
        sta     ship_y_pos                      ; 871C 85 C4                    ..
        jsr     erase_ship                      ; 871E 20 88 B5                  ..
        jsr     draw_ship                       ; 8721 20 A1 B5                  ..
L8724:  ldy     #$0A                            ; 8724 A0 0A                    ..
        sty     sprite_y                        ; 8726 84 DF                    ..
        ldy     #$22                            ; 8728 A0 22                    ."
        sty     sprite_x                        ; 872A 84 E3                    ..
        lda     current_player                  ; 872C A5 F1                    ..
        cmp     #$01                            ; 872E C9 01                    ..
        beq     draw_smartbombs                 ; 8730 F0 04                    ..
        ldy     #$7A                            ; 8732 A0 7A                    .z
        sty     sprite_x                        ; 8734 84 E3                    ..
; draw smartbombs in the HUD, if any are left (max 3)
draw_smartbombs:
        ldy     #$07                            ; 8736 A0 07                    ..
        sty     current_sprite                  ; 8738 84 F9                    ..
        lda     smartbombs                      ; 873A A5 A5                    ..
        beq     L8760                           ; 873C F0 22                    ."
        cmp     #$04                            ; 873E C9 04                    ..
        bcc     smartbombs_ok                   ; 8740 90 02                    ..
        lda     #$03                            ; 8742 A9 03                    ..
; A holds number of visible bombs, 1 to 3
smartbombs_ok:
        pha                                     ; 8744 48                       H
        jsr     erase_sprite                    ; 8745 20 2C AB                  ,.
        lda     animation_counter               ; 8748 A5 85                    ..
        and     #$02                            ; 874A 29 02                    ).
        lsr     a                               ; 874C 4A                       J
        clc                                     ; 874D 18                       .
        adc     #$1A                            ; 874E 69 1A                    i.
        jsr     draw_sprite_left_copy           ; 8750 20 00 1F                  ..
        clc                                     ; 8753 18                       .
        lda     sprite_y                        ; 8754 A5 DF                    ..
        adc     #$06                            ; 8756 69 06                    i.
        sta     sprite_y                        ; 8758 85 DF                    ..
        pla                                     ; 875A 68                       h
        sec                                     ; 875B 38                       8
        sbc     #$01                            ; 875C E9 01                    ..
        bne     smartbombs_ok                   ; 875E D0 E4                    ..
L8760:  lda     sprite_y                        ; 8760 A5 DF                    ..
        cmp     #$18                            ; 8762 C9 18                    ..
        bcs     L8773                           ; 8764 B0 0D                    ..
        jsr     erase_sprite                    ; 8766 20 2C AB                  ,.
        clc                                     ; 8769 18                       .
        lda     sprite_y                        ; 876A A5 DF                    ..
        adc     #$06                            ; 876C 69 06                    i.
        sta     sprite_y                        ; 876E 85 DF                    ..
        jmp     L8760                           ; 8770 4C 60 87                 L`.

; ----------------------------------------------------------------------------
L8773:  pla                                     ; 8773 68                       h
        sta     ship_direction                  ; 8774 85 C5                    ..
        pla                                     ; 8776 68                       h
        sta     ship_y_pos                      ; 8777 85 C4                    ..
        pla                                     ; 8779 68                       h
        sta     ship_x_pos                      ; 877A 85 C3                    ..
        pla                                     ; 877C 68                       h
        sta     animation_counter               ; 877D 85 85                    ..
        rts                                     ; 877F 60                       `

; ----------------------------------------------------------------------------
; update HUD
draw_p2_lives_and_bombs:
        lda     players                         ; 8780 A5 E2                    ..
        cmp     #$02                            ; 8782 C9 02                    ..
        bcs     L8787                           ; 8784 B0 01                    ..
        rts                                     ; 8786 60                       `

; ----------------------------------------------------------------------------
L8787:  lda     animation_counter               ; 8787 A5 85                    ..
        pha                                     ; 8789 48                       H
        inc     ship_anim_counter               ; 878A E6 AA                    ..
        lda     ship_anim_counter               ; 878C A5 AA                    ..
        sta     animation_counter               ; 878E 85 85                    ..
        lda     ship_x_pos                      ; 8790 A5 C3                    ..
        pha                                     ; 8792 48                       H
        lda     ship_y_pos                      ; 8793 A5 C4                    ..
        pha                                     ; 8795 48                       H
        lda     ship_direction                  ; 8796 A5 C5                    ..
        pha                                     ; 8798 48                       H
        lda     #$00                            ; 8799 A9 00                    ..
        sta     ship_direction                  ; 879B 85 C5                    ..
        lda     current_player                  ; 879D A5 F1                    ..
        cmp     #$02                            ; 879F C9 02                    ..
        beq     L87A7                           ; 87A1 F0 04                    ..
        lda     #$FF                            ; 87A3 A9 FF                    ..
        sta     ship_direction                  ; 87A5 85 C5                    ..
L87A7:  lda     current_player                  ; 87A7 A5 F1                    ..
        cmp     #$01                            ; 87A9 C9 01                    ..
        beq     L87B3                           ; 87AB F0 06                    ..
        lda     p1_sav_lives                    ; 87AD AD C6 17                 ...
        jmp     L87B6                           ; 87B0 4C B6 87                 L..

; ----------------------------------------------------------------------------
L87B3:  lda     p2_sav_lives                    ; 87B3 AD C6 19                 ...
L87B6:  clc                                     ; 87B6 18                       .
        adc     #$01                            ; 87B7 69 01                    i.
        cmp     #$02                            ; 87B9 C9 02                    ..
        beq     L87F3                           ; 87BB F0 36                    .6
        bcc     L880B                           ; 87BD 90 4C                    .L
        cmp     #$03                            ; 87BF C9 03                    ..
        beq     L87DB                           ; 87C1 F0 18                    ..
        lda     #$1C                            ; 87C3 A9 1C                    ..
        sta     ship_x_pos                      ; 87C5 85 C3                    ..
        lda     current_player                  ; 87C7 A5 F1                    ..
        cmp     #$01                            ; 87C9 C9 01                    ..
        bne     L87D1                           ; 87CB D0 04                    ..
        lda     #$96                            ; 87CD A9 96                    ..
        sta     ship_x_pos                      ; 87CF 85 C3                    ..
L87D1:  lda     #$00                            ; 87D1 A9 00                    ..
        sta     ship_y_pos                      ; 87D3 85 C4                    ..
        jsr     erase_ship                      ; 87D5 20 88 B5                  ..
        jsr     draw_ship                       ; 87D8 20 A1 B5                  ..
L87DB:  lda     #$10                            ; 87DB A9 10                    ..
        sta     ship_x_pos                      ; 87DD 85 C3                    ..
        lda     current_player                  ; 87DF A5 F1                    ..
        cmp     #$01                            ; 87E1 C9 01                    ..
        bne     L87E9                           ; 87E3 D0 04                    ..
        lda     #$8A                            ; 87E5 A9 8A                    ..
        sta     ship_x_pos                      ; 87E7 85 C3                    ..
L87E9:  lda     #$00                            ; 87E9 A9 00                    ..
        sta     ship_y_pos                      ; 87EB 85 C4                    ..
        jsr     erase_ship                      ; 87ED 20 88 B5                  ..
        jsr     draw_ship                       ; 87F0 20 A1 B5                  ..
L87F3:  lda     #$04                            ; 87F3 A9 04                    ..
        sta     ship_x_pos                      ; 87F5 85 C3                    ..
        lda     current_player                  ; 87F7 A5 F1                    ..
        cmp     #$01                            ; 87F9 C9 01                    ..
        bne     L8801                           ; 87FB D0 04                    ..
        lda     #$7E                            ; 87FD A9 7E                    .~
        sta     ship_x_pos                      ; 87FF 85 C3                    ..
L8801:  lda     #$00                            ; 8801 A9 00                    ..
        sta     ship_y_pos                      ; 8803 85 C4                    ..
        jsr     erase_ship                      ; 8805 20 88 B5                  ..
        jsr     draw_ship                       ; 8808 20 A1 B5                  ..
L880B:  ldy     #$0A                            ; 880B A0 0A                    ..
        sty     sprite_y                        ; 880D 84 DF                    ..
        ldy     #$22                            ; 880F A0 22                    ."
        sty     sprite_x                        ; 8811 84 E3                    ..
        lda     current_player                  ; 8813 A5 F1                    ..
        cmp     #$01                            ; 8815 C9 01                    ..
        bne     L881D                           ; 8817 D0 04                    ..
        ldy     #$7A                            ; 8819 A0 7A                    .z
        sty     sprite_x                        ; 881B 84 E3                    ..
L881D:  ldy     #$07                            ; 881D A0 07                    ..
        sty     current_sprite                  ; 881F 84 F9                    ..
        lda     current_player                  ; 8821 A5 F1                    ..
        cmp     #$01                            ; 8823 C9 01                    ..
        beq     L882D                           ; 8825 F0 06                    ..
        lda     p1_sav_bombs                    ; 8827 AD C7 17                 ...
        jmp     L8830                           ; 882A 4C 30 88                 L0.

; ----------------------------------------------------------------------------
L882D:  lda     p2_sav_bombs                    ; 882D AD C7 19                 ...
L8830:  beq     L8854                           ; 8830 F0 22                    ."
        cmp     #$04                            ; 8832 C9 04                    ..
        bcc     L8838                           ; 8834 90 02                    ..
        lda     #$03                            ; 8836 A9 03                    ..
L8838:  pha                                     ; 8838 48                       H
        jsr     erase_sprite                    ; 8839 20 2C AB                  ,.
        lda     animation_counter               ; 883C A5 85                    ..
        and     #$02                            ; 883E 29 02                    ).
        lsr     a                               ; 8840 4A                       J
        clc                                     ; 8841 18                       .
        adc     #$1A                            ; 8842 69 1A                    i.
        jsr     draw_sprite_left_copy           ; 8844 20 00 1F                  ..
        clc                                     ; 8847 18                       .
        lda     sprite_y                        ; 8848 A5 DF                    ..
        adc     #$06                            ; 884A 69 06                    i.
        sta     sprite_y                        ; 884C 85 DF                    ..
        pla                                     ; 884E 68                       h
        sec                                     ; 884F 38                       8
        sbc     #$01                            ; 8850 E9 01                    ..
        bne     L8838                           ; 8852 D0 E4                    ..
L8854:  lda     sprite_y                        ; 8854 A5 DF                    ..
        cmp     #$18                            ; 8856 C9 18                    ..
        bcs     L8867                           ; 8858 B0 0D                    ..
        jsr     erase_sprite                    ; 885A 20 2C AB                  ,.
        clc                                     ; 885D 18                       .
        lda     sprite_y                        ; 885E A5 DF                    ..
        adc     #$06                            ; 8860 69 06                    i.
        sta     sprite_y                        ; 8862 85 DF                    ..
        jmp     L8854                           ; 8864 4C 54 88                 LT.

; ----------------------------------------------------------------------------
L8867:  pla                                     ; 8867 68                       h
        sta     ship_direction                  ; 8868 85 C5                    ..
        pla                                     ; 886A 68                       h
        sta     ship_y_pos                      ; 886B 85 C4                    ..
        pla                                     ; 886D 68                       h
        sta     ship_x_pos                      ; 886E 85 C3                    ..
        pla                                     ; 8870 68                       h
        sta     animation_counter               ; 8871 85 85                    ..
        rts                                     ; 8873 60                       `

; ----------------------------------------------------------------------------
; takes delay time in A. only ever called with A=$80 (delays a bit less than 3 frames) or A=$FF (almost 7 frames)
delay_loop:
        pha                                     ; 8874 48                       H
        sec                                     ; 8875 38                       8
dl_wait:sbc     #$01                            ; 8876 E9 01                    ..
        bcs     dl_wait                         ; 8878 B0 FC                    ..
        pla                                     ; 887A 68                       h
        sec                                     ; 887B 38                       8
        sbc     #$01                            ; 887C E9 01                    ..
        bcs     delay_loop                      ; 887E B0 F4                    ..
        rts                                     ; 8880 60                       `

; ----------------------------------------------------------------------------
; did the player press a key to use hyperspace?
check_hyperspace:
        bit     hyperspace_flag                 ; 8881 24 AE                    $.
        bmi     hyperspace_pressed              ; 8883 30 01                    0.
        rts                                     ; 8885 60                       `

; ----------------------------------------------------------------------------
; yes, he did
hyperspace_pressed:
        jsr     play_materialize                ; 8886 20 32 8E                  2.
        jsr     clear_screen                    ; 8889 20 A1 B8                  ..
        jsr     clear_player_shots              ; 888C 20 F1 B7                  ..
        inc     $D0                             ; 888F E6 D0                    ..
        jsr     clear_scanner_draw_planet_and_humans; 8891 20 5E 9E              ^.
        jsr     draw_scanner_border_and_planet  ; 8894 20 B1 9F                  ..
        lda     #$10                            ; 8897 A9 10                    ..
hsp_loop:
        pha                                     ; 8899 48                       H
        jsr     animate_starfield               ; 889A 20 32 A8                  2.
        pla                                     ; 889D 68                       h
        sec                                     ; 889E 38                       8
        sbc     #$01                            ; 889F E9 01                    ..
        bne     hsp_loop                        ; 88A1 D0 F6                    ..
        jsr     draw_scores                     ; 88A3 20 42 94                  B.
        jsr     draw_p1_lives_and_bombs         ; 88A6 20 B0 86                  ..
        jsr     hyperspace_implosion            ; 88A9 20 E7 97                  ..
        lsr     hyperspace_flag                 ; 88AC 46 AE                    F.
; don't ever kill the 'player' in demo mode (game_type==0)
hsp_check_demo:
        lda     game_type                       ; 88AE A5 E1                    ..
        beq     hsp_done                        ; 88B0 F0 0A                    ..
; kill player if RANDOM >= $AA (in other words, 33% of the time!)
check_hyperspace_fatal:
        lda     RANDOM                          ; 88B2 AD 0A D2                 ...
        cmp     #$AA                            ; 88B5 C9 AA                    ..
        bcc     hsp_done                        ; 88B7 90 03                    ..
        jmp     start_player_death              ; 88B9 4C 4C B6                 LL.

; ----------------------------------------------------------------------------
hsp_done:
        rts                                     ; 88BC 60                       `

; ----------------------------------------------------------------------------
; animate the demo-game ship
demo_logic:
        sec                                     ; 88BD 38                       8
        ror     invuln_flag                     ; 88BE 66 ED                    f.
        sec                                     ; 88C0 38                       8
        ror     exhaust_flag                    ; 88C1 6E 2B 0D                 n+.
        lda     #$05                            ; 88C4 A9 05                    ..
        sta     ship_delta                      ; 88C6 85 D5                    ..
        lda     ship_move_delay                 ; 88C8 A5 93                    ..
        and     #$03                            ; 88CA 29 03                    ).
        beq     dl_check_move                   ; 88CC F0 03                    ..
        jsr     inertia_logic                   ; 88CE 20 81 86                  ..
; is it time to move the ship?
dl_check_move:
        inc     ship_move_delay                 ; 88D1 E6 93                    ..
        lda     ship_move_delay                 ; 88D3 A5 93                    ..
        and     #$03                            ; 88D5 29 03                    ).
        beq     dl_check_hyper                  ; 88D7 F0 52                    .R
        lda     #$00                            ; 88D9 A9 00                    ..
        sta     $98                             ; 88DB 85 98                    ..
dl_vert_move:
        ldy     $98                             ; 88DD A4 98                    ..
        lda     sprite_list,y                   ; 88DF B9 EB 0A                 ...
        bne     dl_vert_delta                   ; 88E2 D0 0C                    ..
dl_vm_next:
        lda     $98                             ; 88E4 A5 98                    ..
        clc                                     ; 88E6 18                       .
        adc     #$04                            ; 88E7 69 04                    i.
        sta     $98                             ; 88E9 85 98                    ..
        bpl     dl_vert_move                    ; 88EB 10 F0                    ..
        jmp     L8603                           ; 88ED 4C 03 86                 L..

; ----------------------------------------------------------------------------
; move the ship up or down, towards the sprite we're considering. actual movement ends up as the sum of all the calls here
dl_vert_delta:
        lda     sprite_list+3,y                 ; 88F0 B9 EE 0A                 ...
        and     #$07                            ; 88F3 29 07                    ).
        beq     dl_vm_next                      ; 88F5 F0 ED                    ..
        cmp     #$03                            ; 88F7 C9 03                    ..
        beq     dl_vm_next                      ; 88F9 F0 E9                    ..
        cmp     #$07                            ; 88FB C9 07                    ..
        beq     dl_vm_next                      ; 88FD F0 E5                    ..
        lda     sprite_list,y                   ; 88FF B9 EB 0A                 ...
        cmp     ship_y_pos                      ; 8902 C5 C4                    ..
        ror     a                               ; 8904 6A                       j
        eor     #$FF                            ; 8905 49 FF                    I.
        sta     $F3                             ; 8907 85 F3                    ..
        bit     $F3                             ; 8909 24 F3                    $.
        bpl     dl_down                         ; 890B 10 0F                    ..
        dec     ship_y_pos                      ; 890D C6 C4                    ..
        lda     ship_y_pos                      ; 890F A5 C4                    ..
        cmp     #$20                            ; 8911 C9 20                    . 
        bcs     dl_done                         ; 8913 B0 44                    .D
        lda     #$20                            ; 8915 A9 20                    . 
        sta     ship_y_pos                      ; 8917 85 C4                    ..
        jmp     L8603                           ; 8919 4C 03 86                 L..

; ----------------------------------------------------------------------------
; move the ship down
dl_down:inc     ship_y_pos                      ; 891C E6 C4                    ..
        lda     ship_y_pos                      ; 891E A5 C4                    ..
        cmp     #$A0                            ; 8920 C9 A0                    ..
        bcc     dl_done                         ; 8922 90 35                    .5
        lda     #$A0                            ; 8924 A9 A0                    ..
        sta     ship_y_pos                      ; 8926 85 C4                    ..
        jmp     L8603                           ; 8928 4C 03 86                 L..

; ----------------------------------------------------------------------------
dl_check_hyper:
        lda     level_jiffies_lo                ; 892B A5 87                    ..
        beq     dl_hyperspace                   ; 892D F0 1D                    ..
        lda     enemy_count                     ; 892F A5 9C                    ..
        cmp     #$08                            ; 8931 C9 08                    ..
        bcs     dl_smartbomb                    ; 8933 B0 1D                    ..
        lda     RANDOM                          ; 8935 AD 0A D2                 ...
        and     #$07                            ; 8938 29 07                    ).
        bne     dl_done                         ; 893A D0 1D                    ..
        bit     planet_dead_flag                ; 893C 24 A0                    $.
        bmi     dl_trigger                      ; 893E 30 06                    0.
        lda     ship_y_pos                      ; 8940 A5 C4                    ..
        cmp     #$90                            ; 8942 C9 90                    ..
        bcs     dl_done                         ; 8944 B0 13                    ..
dl_trigger:
        jsr     handle_trigger                  ; 8946 20 D0 99                  ..
        jmp     dl_done                         ; 8949 4C 59 89                 LY.

; ----------------------------------------------------------------------------
dl_hyperspace:
        sec                                     ; 894C 38                       8
        ror     hyperspace_flag                 ; 894D 66 AE                    f.
        jmp     dl_done                         ; 894F 4C 59 89                 LY.

; ----------------------------------------------------------------------------
dl_smartbomb:
        sec                                     ; 8952 38                       8
        ror     spacebar_flag                   ; 8953 66 AC                    f.
        lda     #$00                            ; 8955 A9 00                    ..
        sta     enemy_count                     ; 8957 85 9C                    ..
dl_done:jmp     L8603                           ; 8959 4C 03 86                 L..

; ----------------------------------------------------------------------------
; draw the text for DEFENDER c 1982 ATARI, during the demo game
draw_demo_text:
        lda     $D4                             ; 895C A5 D4                    ..
        and     #$3F                            ; 895E 29 3F                    )?
        beq     ddt_draw                        ; 8960 F0 01                    ..
        rts                                     ; 8962 60                       `

; ----------------------------------------------------------------------------
ddt_draw:
        lda     draw_ok_flag                    ; 8963 A5 AB                    ..
        bpl     draw_demo_text                  ; 8965 10 F5                    ..
        lda     #$01                            ; 8967 A9 01                    ..
        sta     cursor_x                        ; 8969 8D 39 14                 .9.
        lda     #$14                            ; 896C A9 14                    ..
        sta     cursor_y                        ; 896E 8D 3A 14                 .:.
        lda     glyph_color_mask                ; 8971 A5 EE                    ..
        pha                                     ; 8973 48                       H
        lda     level_jiffies_lo                ; 8974 A5 87                    ..
        and     #$03                            ; 8976 29 03                    ).
        tay                                     ; 8978 A8                       .
        lda     L89B5,y                         ; 8979 B9 B5 89                 ...
        sta     glyph_color_mask                ; 897C 85 EE                    ..
        ldy     #$00                            ; 897E A0 00                    ..
ddt_nextchar:
        lda     demo_text,y                     ; 8980 B9 8F 89                 ...
        beq     ddt_done                        ; 8983 F0 06                    ..
        jsr     printchar                       ; 8985 20 2E 97                  ..
        iny                                     ; 8988 C8                       .
        bne     ddt_nextchar                    ; 8989 D0 F5                    ..
ddt_done:
        pla                                     ; 898B 68                       h
        sta     glyph_color_mask                ; 898C 85 EE                    ..
        rts                                     ; 898E 60                       `

; ----------------------------------------------------------------------------
; ' D E F E N D E R    c 1982  A T A R I '
demo_text:
        .byte   $A0,$C4,$A0,$C5,$A0,$C6,$A0,$C5 ; 898F A0 C4 A0 C5 A0 C6 A0 C5  ........
        .byte   $A0,$CE,$A0,$C4,$A0,$C5,$A0,$D2 ; 8997 A0 CE A0 C4 A0 C5 A0 D2  ........
        .byte   $A0,$A0,$A0,$A0,$C0,$A0,$B1,$B9 ; 899F A0 A0 A0 A0 C0 A0 B1 B9  ........
        .byte   $B8,$B2,$A0,$A0,$C1,$A0,$D4,$A0 ; 89A7 B8 B2 A0 A0 C1 A0 D4 A0  ........
        .byte   $C1,$A0,$D2,$A0,$C9,$00         ; 89AF C1 A0 D2 A0 C9 00        ......
L89B5:  .byte   $FF,$AA,$FF,$55                 ; 89B5 FF AA FF 55              ...U
; ----------------------------------------------------------------------------
; save game state to p1_sav_* area
save_p1_state:
        ldx     #$00                            ; 89B9 A2 00                    ..
sp1_loop:
        cpx     #$80                            ; 89BB E0 80                    ..
        bcs     sp1_skip                        ; 89BD B0 0C                    ..
        lda     sprite_list,x                   ; 89BF BD EB 0A                 ...
        sta     p1_sav_sprite_list,x            ; 89C2 9D 00 16                 ...
        lda     sprite_list+128,x               ; 89C5 BD 6B 0B                 .k.
        sta     p1_sav_sprite_list+128,x        ; 89C8 9D 80 16                 ...
sp1_skip:
        lda     actor_list,x                    ; 89CB BD 6B 0C                 .k.
        sta     $1700,x                         ; 89CE 9D 00 17                 ...
        inx                                     ; 89D1 E8                       .
        cpx     #$C0                            ; 89D2 E0 C0                    ..
        bcc     sp1_loop                        ; 89D4 90 E5                    ..
        lda     score                           ; 89D6 AD 2F 14                 ./.
        sta     p1_sav_score                    ; 89D9 8D C0 17                 ...
        lda     score+1                         ; 89DC AD 30 14                 .0.
        sta     p1_sav_score+1                  ; 89DF 8D C1 17                 ...
        lda     score+2                         ; 89E2 AD 31 14                 .1.
        sta     p1_sav_score+2                  ; 89E5 8D C2 17                 ...
        lda     score+3                         ; 89E8 AD 32 14                 .2.
        sta     p1_sav_score+3                  ; 89EB 8D C3 17                 ...
        lda     planet_dead_flag                ; 89EE A5 A0                    ..
        sta     $17C4                           ; 89F0 8D C4 17                 ...
        lda     enemy_firing_freq               ; 89F3 A5 BB                    ..
        sta     p1_sav_fire_freq                ; 89F5 8D C5 17                 ...
        lda     lives                           ; 89F8 A5 9E                    ..
        sta     p1_sav_lives                    ; 89FA 8D C6 17                 ...
        lda     smartbombs                      ; 89FD A5 A5                    ..
        sta     p1_sav_bombs                    ; 89FF 8D C7 17                 ...
        lda     landers_to_spawn                ; 8A02 A5 9B                    ..
        sta     p1_sav_lander_wave_count        ; 8A04 8D C8 17                 ...
        lda     level                           ; 8A07 A5 9A                    ..
        sta     p1_sav_level                    ; 8A09 8D C9 17                 ...
        rts                                     ; 8A0C 60                       `

; ----------------------------------------------------------------------------
; save game state to p2_sav_* area
save_p2_state:
        ldx     #$00                            ; 8A0D A2 00                    ..
sp2_loop:
        cpx     #$80                            ; 8A0F E0 80                    ..
        bcs     sp2_skip                        ; 8A11 B0 0C                    ..
        lda     sprite_list,x                   ; 8A13 BD EB 0A                 ...
        sta     p2_sav_sprite_list,x            ; 8A16 9D 00 18                 ...
        lda     sprite_list+128,x               ; 8A19 BD 6B 0B                 .k.
        sta     p2_sav_sprite_list+128,x        ; 8A1C 9D 80 18                 ...
sp2_skip:
        lda     actor_list,x                    ; 8A1F BD 6B 0C                 .k.
        sta     $1900,x                         ; 8A22 9D 00 19                 ...
        inx                                     ; 8A25 E8                       .
        cpx     #$C0                            ; 8A26 E0 C0                    ..
        bcc     sp2_loop                        ; 8A28 90 E5                    ..
        lda     score                           ; 8A2A AD 2F 14                 ./.
        sta     p2_sav_score                    ; 8A2D 8D C0 19                 ...
        lda     score+1                         ; 8A30 AD 30 14                 .0.
        sta     p2_sav_score+1                  ; 8A33 8D C1 19                 ...
        lda     score+2                         ; 8A36 AD 31 14                 .1.
        sta     p2_sav_score+2                  ; 8A39 8D C2 19                 ...
        lda     score+3                         ; 8A3C AD 32 14                 .2.
        sta     p2_sav_score+3                  ; 8A3F 8D C3 19                 ...
        lda     planet_dead_flag                ; 8A42 A5 A0                    ..
        sta     p2_sav_planet_dead              ; 8A44 8D C4 19                 ...
        lda     enemy_firing_freq               ; 8A47 A5 BB                    ..
        sta     p2_sav_fire_freq                ; 8A49 8D C5 19                 ...
        lda     lives                           ; 8A4C A5 9E                    ..
        sta     p2_sav_lives                    ; 8A4E 8D C6 19                 ...
        lda     smartbombs                      ; 8A51 A5 A5                    ..
        sta     p2_sav_bombs                    ; 8A53 8D C7 19                 ...
        lda     landers_to_spawn                ; 8A56 A5 9B                    ..
        sta     p2_sav_lander_wave_count        ; 8A58 8D C8 19                 ...
        lda     level                           ; 8A5B A5 9A                    ..
        sta     p2_sav_level                    ; 8A5D 8D C9 19                 ...
        rts                                     ; 8A60 60                       `

; ----------------------------------------------------------------------------
; restore game state from p1_sav_* area
load_p1_state:
        ldx     #$00                            ; 8A61 A2 00                    ..
lp1_loop:
        cpx     #$80                            ; 8A63 E0 80                    ..
        bcs     lp1_skip                        ; 8A65 B0 0C                    ..
        lda     p1_sav_sprite_list,x            ; 8A67 BD 00 16                 ...
        sta     sprite_list,x                   ; 8A6A 9D EB 0A                 ...
        lda     p1_sav_sprite_list+128,x        ; 8A6D BD 80 16                 ...
        sta     sprite_list+128,x               ; 8A70 9D 6B 0B                 .k.
lp1_skip:
        lda     $1700,x                         ; 8A73 BD 00 17                 ...
        sta     actor_list,x                    ; 8A76 9D 6B 0C                 .k.
        inx                                     ; 8A79 E8                       .
        cpx     #$C0                            ; 8A7A E0 C0                    ..
        bcc     lp1_loop                        ; 8A7C 90 E5                    ..
        lda     p1_sav_score                    ; 8A7E AD C0 17                 ...
        sta     score                           ; 8A81 8D 2F 14                 ./.
        lda     p1_sav_score+1                  ; 8A84 AD C1 17                 ...
        sta     score+1                         ; 8A87 8D 30 14                 .0.
        lda     p1_sav_score+2                  ; 8A8A AD C2 17                 ...
        sta     score+2                         ; 8A8D 8D 31 14                 .1.
        lda     p1_sav_score+3                  ; 8A90 AD C3 17                 ...
        sta     score+3                         ; 8A93 8D 32 14                 .2.
        lda     $17C4                           ; 8A96 AD C4 17                 ...
        sta     planet_dead_flag                ; 8A99 85 A0                    ..
        lda     p1_sav_fire_freq                ; 8A9B AD C5 17                 ...
        sta     enemy_firing_freq               ; 8A9E 85 BB                    ..
        lda     p1_sav_lives                    ; 8AA0 AD C6 17                 ...
        sta     lives                           ; 8AA3 85 9E                    ..
        lda     p1_sav_bombs                    ; 8AA5 AD C7 17                 ...
        sta     smartbombs                      ; 8AA8 85 A5                    ..
        lda     p1_sav_lander_wave_count        ; 8AAA AD C8 17                 ...
        sta     landers_to_spawn                ; 8AAD 85 9B                    ..
        lda     p1_sav_level                    ; 8AAF AD C9 17                 ...
        sta     level                           ; 8AB2 85 9A                    ..
        rts                                     ; 8AB4 60                       `

; ----------------------------------------------------------------------------
; restore game state from p2_sav_* area
load_p2_state:
        ldx     #$00                            ; 8AB5 A2 00                    ..
lp2_loop:
        cpx     #$80                            ; 8AB7 E0 80                    ..
        bcs     lp2_skip                        ; 8AB9 B0 0C                    ..
        lda     p2_sav_sprite_list,x            ; 8ABB BD 00 18                 ...
        sta     sprite_list,x                   ; 8ABE 9D EB 0A                 ...
        lda     p2_sav_sprite_list+128,x        ; 8AC1 BD 80 18                 ...
        sta     sprite_list+128,x               ; 8AC4 9D 6B 0B                 .k.
lp2_skip:
        lda     $1900,x                         ; 8AC7 BD 00 19                 ...
        sta     actor_list,x                    ; 8ACA 9D 6B 0C                 .k.
        inx                                     ; 8ACD E8                       .
        cpx     #$C0                            ; 8ACE E0 C0                    ..
        bcc     lp2_loop                        ; 8AD0 90 E5                    ..
        lda     p2_sav_score                    ; 8AD2 AD C0 19                 ...
        sta     score                           ; 8AD5 8D 2F 14                 ./.
        lda     p2_sav_score+1                  ; 8AD8 AD C1 19                 ...
        sta     score+1                         ; 8ADB 8D 30 14                 .0.
        lda     p2_sav_score+2                  ; 8ADE AD C2 19                 ...
        sta     score+2                         ; 8AE1 8D 31 14                 .1.
        lda     p2_sav_score+3                  ; 8AE4 AD C3 19                 ...
        sta     score+3                         ; 8AE7 8D 32 14                 .2.
        lda     p2_sav_planet_dead              ; 8AEA AD C4 19                 ...
        sta     planet_dead_flag                ; 8AED 85 A0                    ..
        lda     p2_sav_fire_freq                ; 8AEF AD C5 19                 ...
        sta     enemy_firing_freq               ; 8AF2 85 BB                    ..
        lda     p2_sav_lives                    ; 8AF4 AD C6 19                 ...
        sta     lives                           ; 8AF7 85 9E                    ..
        lda     p2_sav_bombs                    ; 8AF9 AD C7 19                 ...
        sta     smartbombs                      ; 8AFC 85 A5                    ..
        lda     p2_sav_lander_wave_count        ; 8AFE AD C8 19                 ...
        sta     landers_to_spawn                ; 8B01 85 9B                    ..
        lda     p2_sav_level                    ; 8B03 AD C9 19                 ...
        sta     level                           ; 8B06 85 9A                    ..
        rts                                     ; 8B08 60                       `

; ----------------------------------------------------------------------------
; print PLAYER ONE
print_p1_text:
        lda     #$00                            ; 8B09 A9 00                    ..
        sta     cursor_x                        ; 8B0B 8D 39 14                 .9.
        lda     #$0A                            ; 8B0E A9 0A                    ..
        sta     cursor_y                        ; 8B10 8D 3A 14                 .:.
        ldy     #$00                            ; 8B13 A0 00                    ..
pp1_next:
        lda     player_one_text,y               ; 8B15 B9 21 8B                 .!.
        beq     pp1_done                        ; 8B18 F0 06                    ..
        jsr     printchar                       ; 8B1A 20 2E 97                  ..
        iny                                     ; 8B1D C8                       .
        bne     pp1_next                        ; 8B1E D0 F5                    ..
pp1_done:
        rts                                     ; 8B20 60                       `

; ----------------------------------------------------------------------------
; '          P L A Y E R  O N E'
player_one_text:
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0 ; 8B21 A0 A0 A0 A0 A0 A0 A0 A0  ........
        .byte   $A0,$A0,$D0,$A0,$CC,$A0,$C1,$A0 ; 8B29 A0 A0 D0 A0 CC A0 C1 A0  ........
        .byte   $D9,$A0,$C5,$A0,$D2,$A0,$A0,$CF ; 8B31 D9 A0 C5 A0 D2 A0 A0 CF  ........
        .byte   $A0,$CE,$A0,$C5,$00             ; 8B39 A0 CE A0 C5 00           .....
; ----------------------------------------------------------------------------
; print PLAYER TWO
print_p2_text:
        lda     #$00                            ; 8B3E A9 00                    ..
        sta     cursor_x                        ; 8B40 8D 39 14                 .9.
        lda     #$0A                            ; 8B43 A9 0A                    ..
        sta     cursor_y                        ; 8B45 8D 3A 14                 .:.
        ldy     #$00                            ; 8B48 A0 00                    ..
pp2_next:
        lda     player_two_text,y               ; 8B4A B9 56 8B                 .V.
        beq     pp2_done                        ; 8B4D F0 06                    ..
        jsr     printchar                       ; 8B4F 20 2E 97                  ..
        iny                                     ; 8B52 C8                       .
        bne     pp2_next                        ; 8B53 D0 F5                    ..
pp2_done:
        rts                                     ; 8B55 60                       `

; ----------------------------------------------------------------------------
; '          P L A Y E R  T W O'
player_two_text:
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0 ; 8B56 A0 A0 A0 A0 A0 A0 A0 A0  ........
        .byte   $A0,$A0,$D0,$A0,$CC,$A0,$C1,$A0 ; 8B5E A0 A0 D0 A0 CC A0 C1 A0  ........
        .byte   $D9,$A0,$C5,$A0,$D2,$A0,$A0,$D4 ; 8B66 D9 A0 C5 A0 D2 A0 A0 D4  ........
        .byte   $A0,$D7,$A0,$CF,$00             ; 8B6E A0 D7 A0 CF 00           .....
; ----------------------------------------------------------------------------
; print 40 spaces over the PLAYER (ONE|TWO) message
clear_prompt_text:
        lda     #$00                            ; 8B73 A9 00                    ..
        sta     cursor_x                        ; 8B75 8D 39 14                 .9.
        lda     #$0A                            ; 8B78 A9 0A                    ..
        sta     cursor_y                        ; 8B7A 8D 3A 14                 .:.
        ldy     #$00                            ; 8B7D A0 00                    ..
cpt_next_char:
        lda     #$A0                            ; 8B7F A9 A0                    ..
        jsr     printchar                       ; 8B81 20 2E 97                  ..
        iny                                     ; 8B84 C8                       .
        cpy     #$28                            ; 8B85 C0 28                    .(
        bcc     cpt_next_char                   ; 8B87 90 F6                    ..
        rts                                     ; 8B89 60                       `

; ----------------------------------------------------------------------------
; see if player pressed the space bar (spacebar_flag >= $80)
smartbomb_check:
        lda     spacebar_flag                   ; 8B8A A5 AC                    ..
        bmi     smartbomb_yes                   ; 8B8C 30 16                    0.
; copy protection. if we're running from RAM, cause game to jump to the title screen, then refuse to start
ram_self_destruct_2:
        lda     swarmer_spawn_y_offsets         ; 8B8E AD 68 B5                 .h.
        pha                                     ; 8B91 48                       H
        eor     #$FF                            ; 8B92 49 FF                    I.
        sta     swarmer_spawn_y_offsets         ; 8B94 8D 68 B5                 .h.
        pla                                     ; 8B97 68                       h
        cmp     swarmer_spawn_y_offsets         ; 8B98 CD 68 B5                 .h.
        beq     rom_ok                          ; 8B9B F0 06                    ..
        sec                                     ; 8B9D 38                       8
        ror     protection_flag                 ; 8B9E 66 F8                    f.
        jmp     init_title_screen               ; 8BA0 4C 31 80                 L1.

; ----------------------------------------------------------------------------
; if we get here, we're running from ROM
rom_ok: rts                                     ; 8BA3 60                       `

; ----------------------------------------------------------------------------
; see if we have any bombs left, if so, detonate
smartbomb_yes:
        lda     #$00                            ; 8BA4 A9 00                    ..
        sta     spacebar_flag                   ; 8BA6 85 AC                    ..
        lda     smartbombs                      ; 8BA8 A5 A5                    ..
        beq     ram_self_destruct_2             ; 8BAA F0 E2                    ..
detonate_smartbomb:
        dec     smartbombs                      ; 8BAC C6 A5                    ..
        jsr     play_smartbomb                  ; 8BAE 20 4E 8E                  N.
        lda     #$00                            ; 8BB1 A9 00                    ..
        sta     $98                             ; 8BB3 85 98                    ..
        lda     #$0F                            ; 8BB5 A9 0F                    ..
        sta     COLOR4                          ; 8BB7 8D C8 02                 ...
        jmp     smartbomb_kill_stuff            ; 8BBA 4C D0 8B                 L..

; ----------------------------------------------------------------------------
kill_next:
        lda     $98                             ; 8BBD A5 98                    ..
        clc                                     ; 8BBF 18                       .
        adc     #$04                            ; 8BC0 69 04                    i.
        sta     $98                             ; 8BC2 85 98                    ..
        bpl     smartbomb_kill_stuff            ; 8BC4 10 0A                    ..
        lda     #$00                            ; 8BC6 A9 00                    ..
        sta     spacebar_flag                   ; 8BC8 85 AC                    ..
        lda     #$00                            ; 8BCA A9 00                    ..
        sta     COLOR4                          ; 8BCC 8D C8 02                 ...
        rts                                     ; 8BCF 60                       `

; ----------------------------------------------------------------------------
; kill every enemy on the screen
smartbomb_kill_stuff:
        jsr     smartbomb_flash                 ; 8BD0 20 0D 9C                  ..
        lda     COLOR4                          ; 8BD3 AD C8 02                 ...
        eor     #$0F                            ; 8BD6 49 0F                    I.
        sta     COLOR4                          ; 8BD8 8D C8 02                 ...
        ldy     $98                             ; 8BDB A4 98                    ..
        lda     sprite_list,y                   ; 8BDD B9 EB 0A                 ...
        beq     kill_next                       ; 8BE0 F0 DB                    ..
        sta     sprite_y                        ; 8BE2 85 DF                    ..
        lda     sprite_list+1,y                 ; 8BE4 B9 EC 0A                 ...
        sta     $DD                             ; 8BE7 85 DD                    ..
        lda     sprite_list+2,y                 ; 8BE9 B9 ED 0A                 ...
        sta     $DE                             ; 8BEC 85 DE                    ..
        sec                                     ; 8BEE 38                       8
        lda     $DD                             ; 8BEF A5 DD                    ..
        sbc     $8B                             ; 8BF1 E5 8B                    ..
        sta     sprite_x                        ; 8BF3 85 E3                    ..
        lda     $DE                             ; 8BF5 A5 DE                    ..
        sbc     $8C                             ; 8BF7 E5 8C                    ..
        sta     $E4                             ; 8BF9 85 E4                    ..
        bcs     L8C09                           ; 8BFB B0 0C                    ..
        lda     sprite_x                        ; 8BFD A5 E3                    ..
        adc     #$80                            ; 8BFF 69 80                    i.
        sta     sprite_x                        ; 8C01 85 E3                    ..
        lda     $E4                             ; 8C03 A5 E4                    ..
        adc     #$02                            ; 8C05 69 02                    i.
        sta     $E4                             ; 8C07 85 E4                    ..
L8C09:  lda     $E4                             ; 8C09 A5 E4                    ..
L8C0B:  bne     kill_next                       ; 8C0B D0 B0                    ..
        lda     sprite_x                        ; 8C0D A5 E3                    ..
        cmp     #$A0                            ; 8C0F C9 A0                    ..
        bcs     kill_next                       ; 8C11 B0 AA                    ..
        tya                                     ; 8C13 98                       .
        pha                                     ; 8C14 48                       H
        lda     animation_counter               ; 8C15 A5 85                    ..
        and     #$04                            ; 8C17 29 04                    ).
        asl     a                               ; 8C19 0A                       .
        clc                                     ; 8C1A 18                       .
        adc     sprite_list+3,y                 ; 8C1B 79 EE 0A                 y..
        and     #$0F                            ; 8C1E 29 0F                    ).
        tay                                     ; 8C20 A8                       .
        lda     scanner_colormask_table,y       ; 8C21 B9 92 A5                 ...
        sta     scanner_colormask               ; 8C24 85 A9                    ..
        pla                                     ; 8C26 68                       h
        tay                                     ; 8C27 A8                       .
        lda     sprite_list+3,y                 ; 8C28 B9 EE 0A                 ...
        sta     current_sprite                  ; 8C2B 85 F9                    ..
        and     #$07                            ; 8C2D 29 07                    ).
        beq     kill_next                       ; 8C2F F0 8C                    ..
        cmp     #$03                            ; 8C31 C9 03                    ..
L8C33:  beq     kill_next                       ; 8C33 F0 88                    ..
        cmp     #$01                            ; 8C35 C9 01                    ..
        beq     L8C43                           ; 8C37 F0 0A                    ..
        cmp     #$05                            ; 8C39 C9 05                    ..
        beq     L8C69                           ; 8C3B F0 2C                    .,
        jsr     sb_kill                         ; 8C3D 20 C3 8C                  ..
        jmp     kill_next                       ; 8C40 4C BD 8B                 L..

; ----------------------------------------------------------------------------
L8C43:  jsr     sb_kill                         ; 8C43 20 C3 8C                  ..
        lda     current_sprite                  ; 8C46 A5 F9                    ..
        cmp     #$11                            ; 8C48 C9 11                    ..
        beq     L8C4F                           ; 8C4A F0 03                    ..
        jmp     kill_next                       ; 8C4C 4C BD 8B                 L..

; ----------------------------------------------------------------------------
L8C4F:  ldy     $98                             ; 8C4F A4 98                    ..
        lda     sprite_list+128,y               ; 8C51 B9 6B 0B                 .k.
        tax                                     ; 8C54 AA                       .
        lda     sprite_list,x                   ; 8C55 BD EB 0A                 ...
        beq     L8C33                           ; 8C58 F0 D9                    ..
        lda     sprite_list+3,x                 ; 8C5A BD EE 0A                 ...
        cmp     #$08                            ; 8C5D C9 08                    ..
        bne     L8C0B                           ; 8C5F D0 AA                    ..
        lda     #$10                            ; 8C61 A9 10                    ..
        sta     sprite_list+3,x                 ; 8C63 9D EE 0A                 ...
        jmp     kill_next                       ; 8C66 4C BD 8B                 L..

; ----------------------------------------------------------------------------
L8C69:  jsr     sb_kill                         ; 8C69 20 C3 8C                  ..
        jsr     get_random                      ; 8C6C 20 F2 8C                  ..
        and     #$03                            ; 8C6F 29 03                    ).
        sta     $E6                             ; 8C71 85 E6                    ..
        sec                                     ; 8C73 38                       8
        lda     #$06                            ; 8C74 A9 06                    ..
        sbc     $E6                             ; 8C76 E5 E6                    ..
        sta     $E5                             ; 8C78 85 E5                    ..
        lda     $E5                             ; 8C7A A5 E5                    ..
L8C7C:  pha                                     ; 8C7C 48                       H
        jsr     L8C9E                           ; 8C7D 20 9E 8C                  ..
        pla                                     ; 8C80 68                       h
        sec                                     ; 8C81 38                       8
        sbc     #$01                            ; 8C82 E9 01                    ..
        bne     L8C7C                           ; 8C84 D0 F6                    ..
        lda     $E6                             ; 8C86 A5 E6                    ..
        beq     L8C9B                           ; 8C88 F0 11                    ..
L8C8A:  pha                                     ; 8C8A 48                       H
        jsr     get_spawn_pos                   ; 8C8B 20 0C 8D                  ..
        lda     #$06                            ; 8C8E A9 06                    ..
        sta     current_sprite                  ; 8C90 85 F9                    ..
        jsr     add_to_sprite_list              ; 8C92 20 A5 A4                  ..
        pla                                     ; 8C95 68                       h
        sec                                     ; 8C96 38                       8
        sbc     #$01                            ; 8C97 E9 01                    ..
        bne     L8C8A                           ; 8C99 D0 EF                    ..
L8C9B:  jmp     kill_next                       ; 8C9B 4C BD 8B                 L..

; ----------------------------------------------------------------------------
L8C9E:  lda     #$06                            ; 8C9E A9 06                    ..
        jsr     add_points                      ; 8CA0 20 B2 A7                  ..
        jsr     get_random                      ; 8CA3 20 F2 8C                  ..
        and     #$0F                            ; 8CA6 29 0F                    ).
        sbc     #$07                            ; 8CA8 E9 07                    ..
        clc                                     ; 8CAA 18                       .
        adc     $C9                             ; 8CAB 65 C9                    e.
        sta     $C9                             ; 8CAD 85 C9                    ..
        jsr     get_random                      ; 8CAF 20 F2 8C                  ..
        and     #$0F                            ; 8CB2 29 0F                    ).
        sbc     #$07                            ; 8CB4 E9 07                    ..
        clc                                     ; 8CB6 18                       .
        adc     $CA                             ; 8CB7 65 CA                    e.
        sta     $CA                             ; 8CB9 85 CA                    ..
        lda     #$01                            ; 8CBB A9 01                    ..
        sta     $CB                             ; 8CBD 85 CB                    ..
        jsr     start_enemy_explosion           ; 8CBF 20 E7 9B                  ..
        rts                                     ; 8CC2 60                       `

; ----------------------------------------------------------------------------
; kill one enemy
sb_kill:ldy     $98                             ; 8CC3 A4 98                    ..
        lda     #$00                            ; 8CC5 A9 00                    ..
        sta     sprite_list,y                   ; 8CC7 99 EB 0A                 ...
        lda     #$80                            ; 8CCA A9 80                    ..
        sta     sprite_list+2,y                 ; 8CCC 99 ED 0A                 ...
        jsr     erase_scanner_sprite            ; 8CCF 20 2D A1                  -.
        jsr     erase_sprite_XXX                ; 8CD2 20 86 A7                  ..
        lda     sprite_x                        ; 8CD5 A5 E3                    ..
        clc                                     ; 8CD7 18                       .
        adc     #$07                            ; 8CD8 69 07                    i.
        sta     sprite_x                        ; 8CDA 85 E3                    ..
        jsr     erase_sprite                    ; 8CDC 20 2C AB                  ,.
        lda     sprite_x                        ; 8CDF A5 E3                    ..
        sta     $C9                             ; 8CE1 85 C9                    ..
        lda     sprite_y                        ; 8CE3 A5 DF                    ..
        sta     $CA                             ; 8CE5 85 CA                    ..
        lda     #$01                            ; 8CE7 A9 01                    ..
        sta     $CB                             ; 8CE9 85 CB                    ..
        jsr     start_enemy_explosion           ; 8CEB 20 E7 9B                  ..
        jsr     add_cursprite_points            ; 8CEE 20 AE A7                  ..
        rts                                     ; 8CF1 60                       `

; ----------------------------------------------------------------------------
; variant of an LFSR. could have just use 'lda RANDOM', this is likely an artifact of Baker's Apple II heritage. Returns 'random' number in A.
get_random:
        clc                                     ; 8CF2 18                       .
        lda     random_seed                     ; 8CF3 A5 C6                    ..
        adc     random_seed+1                   ; 8CF5 65 C7                    e.
        adc     random_seed+2                   ; 8CF7 65 C8                    e.
        pha                                     ; 8CF9 48                       H
        lda     random_seed+1                   ; 8CFA A5 C7                    ..
        sta     random_seed                     ; 8CFC 85 C6                    ..
        lda     random_seed+2                   ; 8CFE A5 C8                    ..
        sta     random_seed+1                   ; 8D00 85 C7                    ..
        pla                                     ; 8D02 68                       h
        sta     random_seed+2                   ; 8D03 85 C8                    ..
        ror     random_seed+2                   ; 8D05 66 C8                    f.
        ror     random_seed+1                   ; 8D07 66 C7                    f.
        ror     random_seed                     ; 8D09 66 C6                    f.
        rts                                     ; 8D0B 60                       `

; ----------------------------------------------------------------------------
; pick a random, valid spot
get_spawn_pos:
        jsr     get_random                      ; 8D0C 20 F2 8C                  ..
        and     #$FE                            ; 8D0F 29 FE                    ).
        sta     $DD                             ; 8D11 85 DD                    ..
        lda     random_seed+1                   ; 8D13 A5 C7                    ..
        and     #$01                            ; 8D15 29 01                    ).
        sta     $DE                             ; 8D17 85 DE                    ..
        eor     $92                             ; 8D19 45 92                    E.
        beq     get_spawn_pos                   ; 8D1B F0 EF                    ..
        jsr     get_random                      ; 8D1D 20 F2 8C                  ..
        and     #$1F                            ; 8D20 29 1F                    ).
        adc     #$30                            ; 8D22 69 30                    i0
        sta     sprite_y                        ; 8D24 85 DF                    ..
        rts                                     ; 8D26 60                       `

; ----------------------------------------------------------------------------
; this is for 'event' sounds like explosions, not the 'drone' nor the engine noise
update_sound:
        inc     cur_sound_timer                 ; 8D27 E6 B6                    ..
        lda     cur_sound_timer                 ; 8D29 A5 B6                    ..
        and     cur_sound_tempo                 ; 8D2B 25 B4                    %.
        bne     us_ok                           ; 8D2D D0 04                    ..
        inc     sound_offset                    ; 8D2F E6 B1                    ..
        inc     sound_offset                    ; 8D31 E6 B1                    ..
us_ok:  ldy     sound_offset                    ; 8D33 A4 B1                    ..
        lda     (sound_ptr),y                   ; 8D35 B1 B2                    ..
        sta     AUDF1                           ; 8D37 8D 00 D2                 ...
        iny                                     ; 8D3A C8                       .
        lda     (sound_ptr),y                   ; 8D3B B1 B2                    ..
        sta     AUDC1                           ; 8D3D 8D 01 D2                 ...
        and     #$0F                            ; 8D40 29 0F                    ).
        bne     us_done                         ; 8D42 D0 06                    ..
        jsr     play_silence                    ; 8D44 20 68 8D                  h.
        jsr     ram_self_destruct_1             ; 8D47 20 7F B4                  ..
us_done:rts                                     ; 8D4A 60                       `

; ----------------------------------------------------------------------------
; play the sound pointed to by Y:A (lsb:msb), if another sound isn't already in progress (X is a priority I think)
play_event_sound:
        cpx     sound_priority                  ; 8D4B E4 B7                    ..
        bcs     priority_ok                     ; 8D4D B0 0A                    ..
        pha                                     ; 8D4F 48                       H
        lda     sound_offset                    ; 8D50 A5 B1                    ..
        cmp     #$20                            ; 8D52 C9 20                    . 
        bcs     sound_not_busy                  ; 8D54 B0 02                    ..
        pla                                     ; 8D56 68                       h
        rts                                     ; 8D57 60                       `

; ----------------------------------------------------------------------------
sound_not_busy:
        pla                                     ; 8D58 68                       h
priority_ok:
        stx     sound_priority                  ; 8D59 86 B7                    ..
        sta     sound_ptr+1                     ; 8D5B 85 B3                    ..
        sty     sound_ptr                       ; 8D5D 84 B2                    ..
        lda     #$00                            ; 8D5F A9 00                    ..
        sta     sound_offset                    ; 8D61 85 B1                    ..
        lda     sound_tempo                     ; 8D63 A5 B5                    ..
        sta     cur_sound_tempo                 ; 8D65 85 B4                    ..
        rts                                     ; 8D67 60                       `

; ----------------------------------------------------------------------------
play_silence:
        lda     #$00                            ; 8D68 A9 00                    ..
        sta     sound_priority                  ; 8D6A 85 B7                    ..
        lda     #$01                            ; 8D6C A9 01                    ..
        sta     sound_tempo                     ; 8D6E 85 B5                    ..
        tax                                     ; 8D70 AA                       .
        lda     #$8E                            ; 8D71 A9 8E                    ..
        ldy     #$86                            ; 8D73 A0 86                    ..
        jsr     play_event_sound                ; 8D75 20 4B 8D                  K.
        rts                                     ; 8D78 60                       `

; ----------------------------------------------------------------------------
; start the drone sound you hear at the title screen & when starting/ending a level. Also silence channel 2 (the engine noise). In BASIC this would be: SOUND 1,0,0,0:SOUND 2,255,10,15:SOUND 3,254,10,15
init_drone:
        lda     #$FF                            ; 8D79 A9 FF                    ..
        sta     AUDF3                           ; 8D7B 8D 04 D2                 ...
        lda     #$FE                            ; 8D7E A9 FE                    ..
        sta     AUDF4                           ; 8D80 8D 06 D2                 ...
        lda     #$AF                            ; 8D83 A9 AF                    ..
        sta     AUDC3                           ; 8D85 8D 05 D2                 ...
        sta     AUDC4                           ; 8D88 8D 07 D2                 ...
        lda     #$1F                            ; 8D8B A9 1F                    ..
        sta     drone_volume                    ; 8D8D 85 BD                    ..
        lda     #$00                            ; 8D8F A9 00                    ..
        sta     AUDF2                           ; 8D91 8D 02 D2                 ...
        sta     AUDC2                           ; 8D94 8D 03 D2                 ...
        rts                                     ; 8D97 60                       `

; ----------------------------------------------------------------------------
play_player_fire:
        ldx     #$03                            ; 8D98 A2 03                    ..
        lda     #$01                            ; 8D9A A9 01                    ..
        sta     sound_tempo                     ; 8D9C 85 B5                    ..
        lda     #$8E                            ; 8D9E A9 8E                    ..
        ldy     #$8A                            ; 8DA0 A0 8A                    ..
        jsr     play_event_sound                ; 8DA2 20 4B 8D                  K.
        rts                                     ; 8DA5 60                       `

; ----------------------------------------------------------------------------
play_swarmer_died:
        ldx     #$05                            ; 8DA6 A2 05                    ..
        lda     #$00                            ; 8DA8 A9 00                    ..
        sta     sound_tempo                     ; 8DAA 85 B5                    ..
        lda     #$91                            ; 8DAC A9 91                    ..
        ldy     #$20                            ; 8DAE A0 20                    . 
        jsr     play_event_sound                ; 8DB0 20 4B 8D                  K.
        rts                                     ; 8DB3 60                       `

; ----------------------------------------------------------------------------
play_lander_died:
        ldx     #$05                            ; 8DB4 A2 05                    ..
        lda     #$00                            ; 8DB6 A9 00                    ..
        sta     sound_tempo                     ; 8DB8 85 B5                    ..
        lda     #$90                            ; 8DBA A9 90                    ..
        ldy     #$DA                            ; 8DBC A0 DA                    ..
        jsr     play_event_sound                ; 8DBE 20 4B 8D                  K.
        rts                                     ; 8DC1 60                       `

; ----------------------------------------------------------------------------
play_baiter_died:
        ldx     #$05                            ; 8DC2 A2 05                    ..
        lda     #$00                            ; 8DC4 A9 00                    ..
        sta     sound_tempo                     ; 8DC6 85 B5                    ..
        lda     #$91                            ; 8DC8 A9 91                    ..
        ldy     #$AC                            ; 8DCA A0 AC                    ..
        jsr     play_event_sound                ; 8DCC 20 4B 8D                  K.
        rts                                     ; 8DCF 60                       `

; ----------------------------------------------------------------------------
play_pod_died:
        ldx     #$1E                            ; 8DD0 A2 1E                    ..
        lda     #$01                            ; 8DD2 A9 01                    ..
        sta     sound_tempo                     ; 8DD4 85 B5                    ..
        lda     #$92                            ; 8DD6 A9 92                    ..
        ldy     #$08                            ; 8DD8 A0 08                    ..
        jsr     play_event_sound                ; 8DDA 20 4B 8D                  K.
        rts                                     ; 8DDD 60                       `

; ----------------------------------------------------------------------------
play_mutant_taunt:
        ldx     #$0A                            ; 8DDE A2 0A                    ..
        lda     #$01                            ; 8DE0 A9 01                    ..
        sta     sound_tempo                     ; 8DE2 85 B5                    ..
        lda     #$90                            ; 8DE4 A9 90                    ..
        ldy     #$6A                            ; 8DE6 A0 6A                    .j
        jsr     play_event_sound                ; 8DE8 20 4B 8D                  K.
        rts                                     ; 8DEB 60                       `

; ----------------------------------------------------------------------------
play_swarmer_taunt:
        ldx     #$0A                            ; 8DEC A2 0A                    ..
        lda     #$00                            ; 8DEE A9 00                    ..
        sta     sound_tempo                     ; 8DF0 85 B5                    ..
        lda     #$90                            ; 8DF2 A9 90                    ..
        ldy     #$1A                            ; 8DF4 A0 1A                    ..
        jsr     play_event_sound                ; 8DF6 20 4B 8D                  K.
        rts                                     ; 8DF9 60                       `

; ----------------------------------------------------------------------------
play_lander_fire:
        ldx     #$0A                            ; 8DFA A2 0A                    ..
        lda     #$00                            ; 8DFC A9 00                    ..
        sta     sound_tempo                     ; 8DFE 85 B5                    ..
        lda     #$90                            ; 8E00 A9 90                    ..
        ldy     #$60                            ; 8E02 A0 60                    .`
        jsr     play_event_sound                ; 8E04 20 4B 8D                  K.
        rts                                     ; 8E07 60                       `

; ----------------------------------------------------------------------------
play_fall:
        ldx     #$14                            ; 8E08 A2 14                    ..
        lda     #$01                            ; 8E0A A9 01                    ..
        sta     sound_tempo                     ; 8E0C 85 B5                    ..
        lda     #$90                            ; 8E0E A9 90                    ..
        ldy     #$A2                            ; 8E10 A0 A2                    ..
        jsr     play_event_sound                ; 8E12 20 4B 8D                  K.
        rts                                     ; 8E15 60                       `

; ----------------------------------------------------------------------------
play_rescued:
        ldx     #$19                            ; 8E16 A2 19                    ..
        lda     #$01                            ; 8E18 A9 01                    ..
        sta     sound_tempo                     ; 8E1A 85 B5                    ..
        lda     #$92                            ; 8E1C A9 92                    ..
        ldy     #$E2                            ; 8E1E A0 E2                    ..
        jsr     play_event_sound                ; 8E20 20 4B 8D                  K.
        rts                                     ; 8E23 60                       `

; ----------------------------------------------------------------------------
play_human_died:
        ldx     #$1E                            ; 8E24 A2 1E                    ..
        lda     #$01                            ; 8E26 A9 01                    ..
        sta     sound_tempo                     ; 8E28 85 B5                    ..
        lda     #$92                            ; 8E2A A9 92                    ..
        ldy     #$B0                            ; 8E2C A0 B0                    ..
        jsr     play_event_sound                ; 8E2E 20 4B 8D                  K.
        rts                                     ; 8E31 60                       `

; ----------------------------------------------------------------------------
play_materialize:
        ldx     #$32                            ; 8E32 A2 32                    .2
        lda     #$01                            ; 8E34 A9 01                    ..
        sta     sound_tempo                     ; 8E36 85 B5                    ..
        lda     #$8E                            ; 8E38 A9 8E                    ..
        ldy     #$CE                            ; 8E3A A0 CE                    ..
        jsr     play_event_sound                ; 8E3C 20 4B 8D                  K.
        rts                                     ; 8E3F 60                       `

; ----------------------------------------------------------------------------
play_distress:
        ldx     #$64                            ; 8E40 A2 64                    .d
        lda     #$00                            ; 8E42 A9 00                    ..
        sta     sound_tempo                     ; 8E44 85 B5                    ..
        lda     #$8F                            ; 8E46 A9 8F                    ..
        ldy     #$12                            ; 8E48 A0 12                    ..
        jsr     play_event_sound                ; 8E4A 20 4B 8D                  K.
        rts                                     ; 8E4D 60                       `

; ----------------------------------------------------------------------------
play_smartbomb:
        ldx     #$7D                            ; 8E4E A2 7D                    .}
        lda     #$01                            ; 8E50 A9 01                    ..
        sta     sound_tempo                     ; 8E52 85 B5                    ..
        lda     #$92                            ; 8E54 A9 92                    ..
        ldy     #$76                            ; 8E56 A0 76                    .v
        jsr     play_event_sound                ; 8E58 20 4B 8D                  K.
        rts                                     ; 8E5B 60                       `

; ----------------------------------------------------------------------------
play_extra_life:
        ldx     #$96                            ; 8E5C A2 96                    ..
        lda     #$01                            ; 8E5E A9 01                    ..
        sta     sound_tempo                     ; 8E60 85 B5                    ..
        lda     #$8F                            ; 8E62 A9 8F                    ..
        ldy     #$DC                            ; 8E64 A0 DC                    ..
        jsr     play_event_sound                ; 8E66 20 4B 8D                  K.
        rts                                     ; 8E69 60                       `

; ----------------------------------------------------------------------------
play_ship_died:
        ldx     #$C8                            ; 8E6A A2 C8                    ..
        lda     #$01                            ; 8E6C A9 01                    ..
        sta     sound_tempo                     ; 8E6E 85 B5                    ..
        lda     #$91                            ; 8E70 A9 91                    ..
        ldy     #$66                            ; 8E72 A0 66                    .f
        jsr     play_event_sound                ; 8E74 20 4B 8D                  K.
        rts                                     ; 8E77 60                       `

; ----------------------------------------------------------------------------
play_planet_explode:
        ldx     #$C8                            ; 8E78 A2 C8                    ..
        lda     #$01                            ; 8E7A A9 01                    ..
        sta     sound_tempo                     ; 8E7C 85 B5                    ..
        lda     #$93                            ; 8E7E A9 93                    ..
        ldy     #$52                            ; 8E80 A0 52                    .R
        jsr     play_event_sound                ; 8E82 20 4B 8D                  K.
        rts                                     ; 8E85 60                       `

; ----------------------------------------------------------------------------
; 'heard' during title screen, and when nothing else is going on
snd_silence:
        .byte   $00,$00,$00,$00                 ; 8E86 00 00 00 00              ....
; heard when player fires a shot
snd_player_fire:
        .byte   $13,$8C,$12,$8C,$11,$8C,$11,$8C ; 8E8A 13 8C 12 8C 11 8C 11 8C  ........
        .byte   $12,$8C,$13,$8C,$14,$8C,$15,$8C ; 8E92 12 8C 13 8C 14 8C 15 8C  ........
        .byte   $16,$8C,$17,$8C,$18,$8C,$18,$8C ; 8E9A 16 8C 17 8C 18 8C 18 8C  ........
        .byte   $19,$8C,$19,$8C,$1A,$8C,$1A,$8C ; 8EA2 19 8C 19 8C 1A 8C 1A 8C  ........
        .byte   $1B,$8C,$1B,$8C,$1B,$8C,$1C,$8C ; 8EAA 1B 8C 1B 8C 1B 8C 1C 8C  ........
        .byte   $1C,$8C,$1C,$8C,$1D,$8C,$1D,$8C ; 8EB2 1C 8C 1C 8C 1D 8C 1D 8C  ........
        .byte   $1D,$8C,$1D,$8C,$1E,$8C,$1E,$8C ; 8EBA 1D 8C 1D 8C 1E 8C 1E 8C  ........
        .byte   $1E,$8C,$1E,$8C,$1F,$8C,$1F,$8C ; 8EC2 1E 8C 1E 8C 1F 8C 1F 8C  ........
        .byte   $1F,$8C,$1F,$80                 ; 8ECA 1F 8C 1F 80              ....
; heard when player ship appears (start of level) or the next group of aliens appears
snd_materialize:
        .byte   $1F,$8F,$1F,$8F,$1F,$8F,$1F,$8F ; 8ECE 1F 8F 1F 8F 1F 8F 1F 8F  ........
        .byte   $1E,$8F,$1E,$8F,$1E,$8F,$1E,$8F ; 8ED6 1E 8F 1E 8F 1E 8F 1E 8F  ........
        .byte   $1D,$8F,$1D,$8F,$1D,$8F,$1D,$8F ; 8EDE 1D 8F 1D 8F 1D 8F 1D 8F  ........
        .byte   $1C,$8F,$1C,$8F,$1C,$8F,$1B,$8F ; 8EE6 1C 8F 1C 8F 1C 8F 1B 8F  ........
        .byte   $1B,$8F,$1B,$8F,$1A,$8F,$1A,$8F ; 8EEE 1B 8F 1B 8F 1A 8F 1A 8F  ........
        .byte   $19,$8F,$19,$8F,$18,$8F,$18,$8F ; 8EF6 19 8F 19 8F 18 8F 18 8F  ........
        .byte   $17,$8F,$16,$8F,$15,$8F,$14,$8F ; 8EFE 17 8F 16 8F 15 8F 14 8F  ........
        .byte   $12,$8F,$11,$8F,$10,$8F,$0E,$8F ; 8F06 12 8F 11 8F 10 8F 0E 8F  ........
        .byte   $0D,$8F,$0C,$80                 ; 8F0E 0D 8F 0C 80              ....
; heard when lander picks up a humanoid
snd_distress:
        .byte   $0C,$AF,$0D,$AF,$0C,$AF,$0D,$AF ; 8F12 0C AF 0D AF 0C AF 0D AF  ........
        .byte   $01,$AB,$01,$AB,$0F,$AB,$10,$AB ; 8F1A 01 AB 01 AB 0F AB 10 AB  ........
        .byte   $0F,$AB,$10,$AB,$0F,$AB,$10,$AB ; 8F22 0F AB 10 AB 0F AB 10 AB  ........
        .byte   $01,$AB,$01,$AB,$0C,$AB,$0D,$AB ; 8F2A 01 AB 01 AB 0C AB 0D AB  ........
        .byte   $0F,$AB,$10,$AB,$0C,$AB,$0D,$AB ; 8F32 0F AB 10 AB 0C AB 0D AB  ........
        .byte   $0F,$AB,$10,$AB,$0C,$AB,$0D,$AB ; 8F3A 0F AB 10 AB 0C AB 0D AB  ........
        .byte   $0E,$AB,$0F,$AB,$0C,$AB,$0D,$AB ; 8F42 0E AB 0F AB 0C AB 0D AB  ........
        .byte   $0F,$AB,$10,$AB,$0C,$AB,$0D,$AB ; 8F4A 0F AB 10 AB 0C AB 0D AB  ........
        .byte   $0E,$AB,$0F,$AB,$0E,$AB,$0D,$AA ; 8F52 0E AB 0F AB 0E AB 0D AA  ........
        .byte   $0C,$A9,$0D,$A8,$0E,$A7,$0D,$A6 ; 8F5A 0C A9 0D A8 0E A7 0D A6  ........
        .byte   $0C,$A5,$0D,$A4,$0C,$A3,$0D,$A2 ; 8F62 0C A5 0D A4 0C A3 0D A2  ........
        .byte   $0C,$A1,$0D,$A0,$FF             ; 8F6A 0C A1 0D A0 FF           .....
; this is in the middle of the sound effects, but it doesn't look like sound data (and doesn't sound like it either)
table_8f6f:
        .byte   $AF,$FF,$AF,$FF,$AF,$FF,$AF,$FF ; 8F6F AF FF AF FF AF FF AF FF  ........
        .byte   $AF,$FF,$AF,$FF,$AE,$FF,$AE,$FF ; 8F77 AF FF AF FF AE FF AE FF  ........
        .byte   $AE,$FF,$AE,$FF,$AF,$FF,$AF,$FF ; 8F7F AE FF AE FF AF FF AF FF  ........
        .byte   $AF,$FF,$AF,$FF,$AF,$FF,$AF,$FF ; 8F87 AF FF AF FF AF FF AF FF  ........
        .byte   $AE,$FF,$AE,$FF,$AE,$FF,$AE,$FF ; 8F8F AE FF AE FF AE FF AE FF  ........
        .byte   $AF,$FF,$AF,$FF,$AF,$FF,$AF,$FF ; 8F97 AF FF AF FF AF FF AF FF  ........
        .byte   $AF,$FF,$AF,$FF,$AE,$FF,$AE,$FF ; 8F9F AF FF AF FF AE FF AE FF  ........
        .byte   $AE,$FF,$AE,$FF,$AF,$FF,$AF,$FF ; 8FA7 AE FF AE FF AF FF AF FF  ........
        .byte   $AF,$FF,$AF,$FF,$AF,$FF,$AF,$FF ; 8FAF AF FF AF FF AF FF AF FF  ........
        .byte   $AE,$FF,$AE,$FF,$AE,$FF,$AE,$FF ; 8FB7 AE FF AE FF AE FF AE FF  ........
        .byte   $AD,$FF,$AD,$FF,$AD,$FF,$AC,$FF ; 8FBF AD FF AD FF AD FF AC FF  ........
        .byte   $AC,$FF,$AC,$FF,$AB,$FF,$AB,$FF ; 8FC7 AC FF AC FF AB FF AB FF  ........
        .byte   $AA,$FF,$AA,$FF,$A9,$FF,$A8,$FF ; 8FCF AA FF AA FF A9 FF A8 FF  ........
        .byte   $A7,$FF,$A6,$FF,$A0             ; 8FD7 A7 FF A6 FF A0           .....
; heard when player gets an extra life
snd_extra_life:
        .byte   $28,$6F,$39,$6F,$12,$6F,$11,$6F ; 8FDC 28 6F 39 6F 12 6F 11 6F  (o9o.o.o
        .byte   $10,$6F,$0F,$6F,$28,$6F,$39,$6F ; 8FE4 10 6F 0F 6F 28 6F 39 6F  .o.o(o9o
        .byte   $0E,$6F,$0D,$6F,$0C,$6F,$0B,$6F ; 8FEC 0E 6F 0D 6F 0C 6F 0B 6F  .o.o.o.o
        .byte   $28,$6F,$39,$6F,$0A,$6F,$09,$6F ; 8FF4 28 6F 39 6F 0A 6F 09 6F  (o9o.o.o
        .byte   $08,$6F,$07,$6F,$28,$6E,$39,$6D ; 8FFC 08 6F 07 6F 28 6E 39 6D  .o.o(n9m
        .byte   $08,$6C,$07,$6B,$06,$6A,$05,$69 ; 9004 08 6C 07 6B 06 6A 05 69  .l.k.j.i
        .byte   $28,$68,$39,$67,$04,$66,$03,$65 ; 900C 28 68 39 67 04 66 03 65  (h9g.f.e
        .byte   $02,$64,$01,$63,$01,$60         ; 9014 02 64 01 63 01 60        .d.c.`
; heard when swarmers are in the area (like a bird call)
snd_swarmer_taunt:
        .byte   $17,$AF,$18,$AF,$19,$AF,$1A,$AF ; 901A 17 AF 18 AF 19 AF 1A AF  ........
        .byte   $1B,$AF,$1C,$A1,$1C,$A1,$17,$AF ; 9022 1B AF 1C A1 1C A1 17 AF  ........
        .byte   $18,$AF,$19,$AF,$1A,$AF,$1B,$AF ; 902A 18 AF 19 AF 1A AF 1B AF  ........
        .byte   $1C,$A1,$1C,$A1,$17,$AF,$18,$AF ; 9032 1C A1 1C A1 17 AF 18 AF  ........
        .byte   $19,$AF,$1A,$AF,$1B,$AF,$1C,$A1 ; 903A 19 AF 1A AF 1B AF 1C A1  ........
        .byte   $1C,$A1,$17,$AF,$18,$AF,$19,$AF ; 9042 1C A1 17 AF 18 AF 19 AF  ........
        .byte   $1A,$AF,$1B,$AF,$1C,$A1,$1C,$A1 ; 904A 1A AF 1B AF 1C A1 1C A1  ........
        .byte   $17,$AF,$18,$AF,$19,$AF,$1A,$AF ; 9052 17 AF 18 AF 19 AF 1A AF  ........
        .byte   $1B,$AF,$1C,$A1,$1C,$A0         ; 905A 1B AF 1C A1 1C A0        ......
; heard when a lander fires a shot
snd_lander_fire:
        .byte   $04,$6F,$05,$6F,$06,$6F,$07,$6F ; 9060 04 6F 05 6F 06 6F 07 6F  .o.o.o.o
        .byte   $09,$60                         ; 9068 09 60                    .`
; heard when a mutant is after you
snd_mutant_taunt:
        .byte   $06,$6F,$05,$6F,$06,$6F,$07,$6F ; 906A 06 6F 05 6F 06 6F 07 6F  .o.o.o.o
        .byte   $08,$6F,$09,$6F,$0A,$6F,$0B,$6F ; 9072 08 6F 09 6F 0A 6F 0B 6F  .o.o.o.o
        .byte   $0C,$6F,$0D,$6F,$0E,$6F,$0F,$6F ; 907A 0C 6F 0D 6F 0E 6F 0F 6F  .o.o.o.o
        .byte   $10,$6F,$11,$6F,$12,$6F,$13,$6F ; 9082 10 6F 11 6F 12 6F 13 6F  .o.o.o.o
        .byte   $14,$6F,$15,$6E,$16,$6D,$17,$6C ; 908A 14 6F 15 6E 16 6D 17 6C  .o.n.m.l
        .byte   $18,$6B,$19,$6A,$1A,$69,$1B,$68 ; 9092 18 6B 19 6A 1A 69 1B 68  .k.j.i.h
        .byte   $1C,$67,$1D,$66,$1E,$65,$1F,$60 ; 909A 1C 67 1D 66 1E 65 1F 60  .g.f.e.`
; heard when a lander carrying a human is shot
snd_fall:
        .byte   $06,$CF,$05,$CF,$06,$CF,$07,$CF ; 90A2 06 CF 05 CF 06 CF 07 CF  ........
        .byte   $08,$CF,$09,$CF,$0A,$CF,$0B,$CF ; 90AA 08 CF 09 CF 0A CF 0B CF  ........
        .byte   $0C,$CF,$0D,$CF,$0E,$CF,$0F,$CF ; 90B2 0C CF 0D CF 0E CF 0F CF  ........
        .byte   $10,$CF,$11,$CF,$12,$CF,$13,$CF ; 90BA 10 CF 11 CF 12 CF 13 CF  ........
        .byte   $14,$CF,$15,$CE,$16,$CD,$17,$CC ; 90C2 14 CF 15 CE 16 CD 17 CC  ........
        .byte   $18,$CB,$19,$CA,$1A,$C9,$1B,$C8 ; 90CA 18 CB 19 CA 1A C9 1B C8  ........
        .byte   $1C,$C7,$1D,$C6,$1E,$C5,$1F,$C0 ; 90D2 1C C7 1D C6 1E C5 1F C0  ........
; heard when we shoot a lander (or a bomber, same sound)
snd_lander_died:
        .byte   $EB,$AF,$FE,$AF,$00,$A1,$00,$A1 ; 90DA EB AF FE AF 00 A1 00 A1  ........
        .byte   $00,$A1,$00,$A1,$00,$A1,$00,$A1 ; 90E2 00 A1 00 A1 00 A1 00 A1  ........
        .byte   $EB,$AE,$FE,$AE,$00,$A1,$00,$A1 ; 90EA EB AE FE AE 00 A1 00 A1  ........
        .byte   $00,$A1,$00,$A1,$00,$A1,$00,$A1 ; 90F2 00 A1 00 A1 00 A1 00 A1  ........
        .byte   $EB,$AA,$FE,$AA,$00,$A1,$00,$A1 ; 90FA EB AA FE AA 00 A1 00 A1  ........
        .byte   $00,$A1,$00,$A1,$00,$A1,$00,$A1 ; 9102 00 A1 00 A1 00 A1 00 A1  ........
        .byte   $EB,$A5,$FE,$A5,$00,$A1,$00,$A1 ; 910A EB A5 FE A5 00 A1 00 A1  ........
        .byte   $00,$A1,$00,$A1,$00,$A1,$00,$A1 ; 9112 00 A1 00 A1 00 A1 00 A1  ........
        .byte   $EB,$A2,$FE,$A2,$00,$A0         ; 911A EB A2 FE A2 00 A0        ......
; heard when a swarmer is shot
snd_swarmer_died:
        .byte   $EB,$8F,$FE,$8F,$00,$81,$00,$81 ; 9120 EB 8F FE 8F 00 81 00 81  ........
        .byte   $00,$81,$00,$81,$00,$81,$00,$81 ; 9128 00 81 00 81 00 81 00 81  ........
        .byte   $EB,$8E,$FE,$8E,$00,$81,$00,$81 ; 9130 EB 8E FE 8E 00 81 00 81  ........
        .byte   $00,$81,$00,$81,$00,$81,$00,$81 ; 9138 00 81 00 81 00 81 00 81  ........
        .byte   $EB,$8A,$FE,$8A,$00,$81,$00,$81 ; 9140 EB 8A FE 8A 00 81 00 81  ........
        .byte   $00,$81,$00,$81,$00,$81,$00,$81 ; 9148 00 81 00 81 00 81 00 81  ........
        .byte   $EB,$87,$FE,$87,$00,$81,$00,$81 ; 9150 EB 87 FE 87 00 81 00 81  ........
        .byte   $00,$81,$00,$81,$00,$81,$00,$81 ; 9158 00 81 00 81 00 81 00 81  ........
        .byte   $EB,$85,$FE,$85,$00,$80         ; 9160 EB 85 FE 85 00 80        ......
; heard when the player's ship explodes
snd_player_died:
        .byte   $0B,$8C,$0F,$86,$13,$8F,$17,$8F ; 9166 0B 8C 0F 86 13 8F 17 8F  ........
        .byte   $18,$86,$19,$8A,$17,$8A,$1B,$85 ; 916E 18 86 19 8A 17 8A 1B 85  ........
        .byte   $1B,$8C,$1C,$89,$1C,$8A,$1A,$8C ; 9176 1B 8C 1C 89 1C 8A 1A 8C  ........
        .byte   $1D,$85,$1A,$8E,$1D,$8A,$1D,$87 ; 917E 1D 85 1A 8E 1D 8A 1D 87  ........
        .byte   $1E,$81,$19,$85,$1E,$89,$1E,$81 ; 9186 1E 81 19 85 1E 89 1E 81  ........
        .byte   $1E,$87,$1E,$86,$1F,$81,$1E,$86 ; 918E 1E 87 1E 86 1F 81 1E 86  ........
        .byte   $01,$81,$1F,$85,$1D,$85,$1F,$85 ; 9196 01 81 1F 85 1D 85 1F 85  ........
        .byte   $1F,$85,$1F,$85,$1F,$85,$01,$81 ; 919E 1F 85 1F 85 1F 85 01 81  ........
        .byte   $20,$84,$20,$81,$20,$80         ; 91A6 20 84 20 81 20 80         . . .
; heard when a baiter is shot (temporary reprieve!)
snd_baiter_died:
        .byte   $6C,$6F,$6C,$61,$66,$61,$66,$61 ; 91AC 6C 6F 6C 61 66 61 66 61  lolafafa
        .byte   $60,$61,$60,$61,$5B,$61,$5B,$61 ; 91B4 60 61 60 61 5B 61 5B 61  `a`a[a[a
        .byte   $55,$6F,$55,$61,$51,$61,$51,$61 ; 91BC 55 6F 55 61 51 61 51 61  UoUaQaQa
        .byte   $4C,$61,$4C,$61,$48,$61,$48,$61 ; 91C4 4C 61 4C 61 48 61 48 61  LaLaHaHa
        .byte   $44,$6F,$44,$61,$40,$61,$40,$61 ; 91CC 44 6F 44 61 40 61 40 61  DoDa@a@a
        .byte   $3C,$61,$3C,$61,$39,$6D,$39,$61 ; 91D4 3C 61 3C 61 39 6D 39 61  <a<a9m9a
        .byte   $35,$61,$35,$61,$32,$61,$32,$61 ; 91DC 35 61 35 61 32 61 32 61  5a5a2a2a
        .byte   $2F,$6A,$2F,$61,$2D,$61,$2D,$61 ; 91E4 2F 6A 2F 61 2D 61 2D 61  /j/a-a-a
        .byte   $2A,$61,$2A,$68,$28,$61,$28,$61 ; 91EC 2A 61 2A 68 28 61 28 61  *a*h(a(a
        .byte   $25,$61,$25,$66,$23,$61,$23,$61 ; 91F4 25 61 25 66 23 61 23 61  %a%f#a#a
        .byte   $21,$64,$21,$61,$1F,$63,$1F,$61 ; 91FC 21 64 21 61 1F 63 1F 61  !d!a.c.a
        .byte   $1D,$62,$1D,$60                 ; 9204 1D 62 1D 60              .b.`
; heard when a pod is killed and spawns a bunch of swarmers
snd_pod_died:
        .byte   $51,$A9,$E5,$AA,$51,$AB,$E5,$AC ; 9208 51 A9 E5 AA 51 AB E5 AC  Q...Q...
        .byte   $51,$AC,$E5,$AC,$51,$AC,$E5,$AB ; 9210 51 AC E5 AC 51 AC E5 AB  Q...Q...
        .byte   $51,$AA,$E5,$A9,$51,$A9,$E5,$A9 ; 9218 51 AA E5 A9 51 A9 E5 A9  Q...Q...
        .byte   $51,$AA,$E5,$AB,$51,$AB,$E5,$AB ; 9220 51 AA E5 AB 51 AB E5 AB  Q...Q...
        .byte   $51,$AB,$E5,$AA,$51,$A9,$E5,$A8 ; 9228 51 AB E5 AA 51 A9 E5 A8  Q...Q...
        .byte   $51,$A8,$E5,$A8,$51,$A9,$E5,$AA ; 9230 51 A8 E5 A8 51 A9 E5 AA  Q...Q...
        .byte   $51,$AA,$E5,$AA,$51,$AA,$E5,$A9 ; 9238 51 AA E5 AA 51 AA E5 A9  Q...Q...
        .byte   $51,$A8,$E5,$A7,$51,$A7,$E5,$A7 ; 9240 51 A8 E5 A7 51 A7 E5 A7  Q...Q...
        .byte   $51,$A8,$E5,$A9,$51,$A9,$E5,$A9 ; 9248 51 A8 E5 A9 51 A9 E5 A9  Q...Q...
        .byte   $51,$A9,$E5,$A8,$51,$A7,$E5,$A6 ; 9250 51 A9 E5 A8 51 A7 E5 A6  Q...Q...
        .byte   $51,$A6,$E5,$A6,$51,$A7,$E5,$A8 ; 9258 51 A6 E5 A6 51 A7 E5 A8  Q...Q...
        .byte   $51,$A8,$E5,$A8,$51,$A8,$E5,$A7 ; 9260 51 A8 E5 A8 51 A8 E5 A7  Q...Q...
        .byte   $51,$A6,$E5,$A5,$51,$A4,$E5,$A3 ; 9268 51 A6 E5 A5 51 A4 E5 A3  Q...Q...
        .byte   $51,$A2,$E5,$A1,$51,$A0         ; 9270 51 A2 E5 A1 51 A0        Q...Q.
; heard when player detonates a smart bomb
snd_smartbomb:
        .byte   $90,$CF,$90,$8F,$90,$88,$90,$85 ; 9276 90 CF 90 8F 90 88 90 85  ........
        .byte   $90,$CF,$90,$8F,$90,$88,$90,$85 ; 927E 90 CF 90 8F 90 88 90 85  ........
        .byte   $90,$CF,$90,$8F,$90,$88,$90,$85 ; 9286 90 CF 90 8F 90 88 90 85  ........
        .byte   $B6,$CF,$B6,$8F,$B6,$8E,$B6,$8D ; 928E B6 CF B6 8F B6 8E B6 8D  ........
        .byte   $B6,$8C,$B6,$8B,$B6,$8A,$B6,$89 ; 9296 B6 8C B6 8B B6 8A B6 89  ........
        .byte   $B6,$88,$B6,$87,$B6,$86,$B6,$85 ; 929E B6 88 B6 87 B6 86 B6 85  ........
        .byte   $B6,$84,$B6,$83,$B6,$82,$B6,$81 ; 92A6 B6 84 B6 83 B6 82 B6 81  ........
        .byte   $B6,$80                         ; 92AE B6 80                    ..
; heard when a human dies (is absorbed, shot, or falls too far)
snd_human_died:
        .byte   $21,$8E,$21,$8E,$21,$8E,$23,$8E ; 92B0 21 8E 21 8E 21 8E 23 8E  !.!.!.#.
        .byte   $28,$8E,$2D,$8E,$35,$8E,$44,$8E ; 92B8 28 8E 2D 8E 35 8E 44 8E  (.-.5.D.
        .byte   $55,$8D,$60,$8D,$6C,$8D,$6C,$8D ; 92C0 55 8D 60 8D 6C 8D 6C 8D  U.`.l.l.
        .byte   $6C,$8C,$72,$8B,$79,$8A,$79,$89 ; 92C8 6C 8C 72 8B 79 8A 79 89  l.r.y.y.
        .byte   $79,$88,$79,$87,$79,$86,$79,$85 ; 92D0 79 88 79 87 79 86 79 85  y.y.y.y.
        .byte   $80,$44,$80,$43,$80,$42,$80,$41 ; 92D8 80 44 80 43 80 42 80 41  .D.C.B.A
        .byte   $80,$40                         ; 92E0 80 40                    .@
; heard when player catches or drops off a human, or when one lands safely on the ground
snd_rescued:
        .byte   $88,$A8,$80,$A9,$79,$AA,$5B,$AB ; 92E2 88 A8 80 A9 79 AA 5B AB  ....y.[.
        .byte   $35,$A6,$32,$A6,$2F,$A6,$88,$A8 ; 92EA 35 A6 32 A6 2F A6 88 A8  5.2./...
        .byte   $80,$A9,$79,$AA,$5B,$AB,$35,$A6 ; 92F2 80 A9 79 AA 5B AB 35 A6  ..y.[.5.
        .byte   $32,$A6,$2D,$A6,$28,$A6,$88,$A8 ; 92FA 32 A6 2D A6 28 A6 88 A8  2.-.(...
        .byte   $80,$A9,$79,$AA,$5B,$AB,$35,$A6 ; 9302 80 A9 79 AA 5B AB 35 A6  ..y.[.5.
        .byte   $32,$A6,$2D,$A6,$25,$A6,$88,$A8 ; 930A 32 A6 2D A6 25 A6 88 A8  2.-.%...
        .byte   $80,$A9,$79,$AA,$5B,$AB,$35,$A6 ; 9312 80 A9 79 AA 5B AB 35 A6  ..y.[.5.
        .byte   $32,$A6,$2A,$A6,$23,$A6,$88,$A8 ; 931A 32 A6 2A A6 23 A6 88 A8  2.*.#...
        .byte   $80,$A9,$79,$AA,$5B,$AB,$35,$A6 ; 9322 80 A9 79 AA 5B AB 35 A6  ..y.[.5.
        .byte   $32,$A6,$28,$A6,$21,$A6,$88,$A8 ; 932A 32 A6 28 A6 21 A6 88 A8  2.(.!...
        .byte   $80,$A9,$79,$AA,$5B,$AB,$35,$A6 ; 9332 80 A9 79 AA 5B AB 35 A6  ..y.[.5.
        .byte   $32,$A6,$25,$A6,$1F,$A6,$88,$A8 ; 933A 32 A6 25 A6 1F A6 88 A8  2.%.....
        .byte   $80,$A9,$79,$AA,$5B,$AB,$35,$A6 ; 9342 80 A9 79 AA 5B AB 35 A6  ..y.[.5.
        .byte   $32,$A6,$23,$A6,$1D,$A6,$88,$A0 ; 934A 32 A6 23 A6 1D A6 88 A0  2.#.....
; heard when the last human dies and the planet asplodes
snd_planet_explode:
        .byte   $16,$8F,$17,$8F,$18,$8F,$19,$8F ; 9352 16 8F 17 8F 18 8F 19 8F  ........
        .byte   $16,$8F,$17,$8F,$18,$8F,$19,$8F ; 935A 16 8F 17 8F 18 8F 19 8F  ........
        .byte   $1A,$8F,$16,$8F,$17,$8F,$18,$8F ; 9362 1A 8F 16 8F 17 8F 18 8F  ........
        .byte   $19,$8F,$1A,$8F,$1B,$8F,$16,$8F ; 936A 19 8F 1A 8F 1B 8F 16 8F  ........
        .byte   $17,$8F,$18,$8F,$19,$8F,$1A,$8F ; 9372 17 8F 18 8F 19 8F 1A 8F  ........
        .byte   $1B,$8F,$1C,$8F,$16,$8F,$17,$8F ; 937A 1B 8F 1C 8F 16 8F 17 8F  ........
        .byte   $18,$8F,$19,$8F,$1A,$8F,$1B,$8F ; 9382 18 8F 19 8F 1A 8F 1B 8F  ........
        .byte   $1C,$8F,$1D,$8F,$1E,$8F,$16,$8F ; 938A 1C 8F 1D 8F 1E 8F 16 8F  ........
        .byte   $17,$8F,$18,$8F,$19,$8F,$1A,$8F ; 9392 17 8F 18 8F 19 8F 1A 8F  ........
        .byte   $1B,$8F,$1C,$8F,$1D,$8F,$1E,$8F ; 939A 1B 8F 1C 8F 1D 8F 1E 8F  ........
        .byte   $1F,$8F,$16,$8F,$17,$8F,$18,$8F ; 93A2 1F 8F 16 8F 17 8F 18 8F  ........
        .byte   $19,$8F,$1A,$8F,$1B,$8F,$1C,$8F ; 93AA 19 8F 1A 8F 1B 8F 1C 8F  ........
        .byte   $1D,$8F,$1E,$8F,$1F,$8F,$20,$8F ; 93B2 1D 8F 1E 8F 1F 8F 20 8F  ...... .
        .byte   $20,$80                         ; 93BA 20 80                     .
; ----------------------------------------------------------------------------
; print 7 spaces over the current player's score. used to flash the score of the current player
clear_score:
        lda     #$01                            ; 93BC A9 01                    ..
        sta     cursor_x                        ; 93BE 8D 39 14                 .9.
        lda     players                         ; 93C1 A5 E2                    ..
        cmp     #$01                            ; 93C3 C9 01                    ..
        beq     fs_set_y                        ; 93C5 F0 0B                    ..
        lda     current_player                  ; 93C7 A5 F1                    ..
        cmp     #$01                            ; 93C9 C9 01                    ..
        beq     fs_set_y                        ; 93CB F0 05                    ..
        lda     #$20                            ; 93CD A9 20                    . 
        sta     cursor_x                        ; 93CF 8D 39 14                 .9.
fs_set_y:
        lda     #$02                            ; 93D2 A9 02                    ..
        sta     cursor_y                        ; 93D4 8D 3A 14                 .:.
        ldy     #$07                            ; 93D7 A0 07                    ..
fs_next_char:
        lda     #$A0                            ; 93D9 A9 A0                    ..
        jsr     printchar                       ; 93DB 20 2E 97                  ..
        dey                                     ; 93DE 88                       .
        bne     fs_next_char                    ; 93DF D0 F8                    ..
fs_done:rts                                     ; 93E1 60                       `

; ----------------------------------------------------------------------------
; draw current player's score in 2p mode. does nothing in 1p mode!
draw_score_2p:
        lda     #$01                            ; 93E2 A9 01                    ..
        sta     cursor_x                        ; 93E4 8D 39 14                 .9.
        lda     players                         ; 93E7 A5 E2                    ..
        cmp     #$01                            ; 93E9 C9 01                    ..
        beq     fs_done                         ; 93EB F0 F4                    ..
        lda     current_player                  ; 93ED A5 F1                    ..
        cmp     #$01                            ; 93EF C9 01                    ..
        bne     ds2_ok                          ; 93F1 D0 05                    ..
        lda     #$20                            ; 93F3 A9 20                    . 
        sta     cursor_x                        ; 93F5 8D 39 14                 .9.
ds2_ok: lda     #$02                            ; 93F8 A9 02                    ..
        sta     cursor_y                        ; 93FA 8D 3A 14                 .:.
        lda     #$FF                            ; 93FD A9 FF                    ..
        sta     glyph_color_mask                ; 93FF 85 EE                    ..
        lsr     leading_zero_flag               ; 9401 4E 10 05                 N..
        lda     current_player                  ; 9404 A5 F1                    ..
        cmp     #$01                            ; 9406 C9 01                    ..
        beq     ds2p_p1                         ; 9408 F0 1C                    ..
        lda     p1_sav_score+3                  ; 940A AD C3 17                 ...
        jsr     print_number                    ; 940D 20 83 94                  ..
        lda     p1_sav_score+2                  ; 9410 AD C2 17                 ...
        jsr     print_number                    ; 9413 20 83 94                  ..
        lda     p1_sav_score+1                  ; 9416 AD C1 17                 ...
        jsr     print_number                    ; 9419 20 83 94                  ..
        sec                                     ; 941C 38                       8
        ror     leading_zero_flag               ; 941D 6E 10 05                 n..
        lda     p1_sav_score                    ; 9420 AD C0 17                 ...
        jmp     print_number                    ; 9423 4C 83 94                 L..

; ----------------------------------------------------------------------------
; draw player 1's score since he's the current player
ds2p_p1:lda     p2_sav_score+3                  ; 9426 AD C3 19                 ...
        jsr     print_number                    ; 9429 20 83 94                  ..
        lda     p2_sav_score+2                  ; 942C AD C2 19                 ...
        jsr     print_number                    ; 942F 20 83 94                  ..
        lda     p2_sav_score+1                  ; 9432 AD C1 19                 ...
        jsr     print_number                    ; 9435 20 83 94                  ..
        sec                                     ; 9438 38                       8
        ror     leading_zero_flag               ; 9439 6E 10 05                 n..
        lda     p2_sav_score                    ; 943C AD C0 19                 ...
        jmp     print_number                    ; 943F 4C 83 94                 L..

; ----------------------------------------------------------------------------
; draw score digits in the HUDs for both players (but not lives nor smartbombs)
draw_scores:
        lda     #$01                            ; 9442 A9 01                    ..
        sta     cursor_x                        ; 9444 8D 39 14                 .9.
        lda     players                         ; 9447 A5 E2                    ..
        cmp     #$01                            ; 9449 C9 01                    ..
        beq     dsc_ok                          ; 944B F0 0B                    ..
        lda     current_player                  ; 944D A5 F1                    ..
        cmp     #$01                            ; 944F C9 01                    ..
        beq     dsc_ok                          ; 9451 F0 05                    ..
        lda     #$20                            ; 9453 A9 20                    . 
        sta     cursor_x                        ; 9455 8D 39 14                 .9.
dsc_ok: lda     #$02                            ; 9458 A9 02                    ..
        sta     cursor_y                        ; 945A 8D 3A 14                 .:.
        lda     #$FF                            ; 945D A9 FF                    ..
        sta     glyph_color_mask                ; 945F 85 EE                    ..
        lsr     leading_zero_flag               ; 9461 4E 10 05                 N..
        lda     score+3                         ; 9464 AD 32 14                 .2.
        jsr     print_number                    ; 9467 20 83 94                  ..
        lda     score+2                         ; 946A AD 31 14                 .1.
        jsr     print_number                    ; 946D 20 83 94                  ..
        lda     score+1                         ; 9470 AD 30 14                 .0.
        jsr     print_number                    ; 9473 20 83 94                  ..
        sec                                     ; 9476 38                       8
        ror     leading_zero_flag               ; 9477 6E 10 05                 n..
        lda     score                           ; 947A AD 2F 14                 ./.
        jsr     print_number                    ; 947D 20 83 94                  ..
        jmp     draw_score_2p                   ; 9480 4C E2 93                 L..

; ----------------------------------------------------------------------------
; print number in A, at current cursor pos. range 0-99 (0-$63). does division by 10. suppress leading zeroes if leading_zero_flag is clear.
print_number:
        sta     $0517                           ; 9483 8D 17 05                 ...
        ldy     #$01                            ; 9486 A0 01                    ..
pn_div10:
        lda     #$00                            ; 9488 A9 00                    ..
        sta     $0518                           ; 948A 8D 18 05                 ...
pn_div10_loop:
        sec                                     ; 948D 38                       8
        lda     $0517                           ; 948E AD 17 05                 ...
        sbc     power_10_table,y                ; 9491 F9 07 95                 ...
        bcc     pn_div10_ok                     ; 9494 90 08                    ..
        sta     $0517                           ; 9496 8D 17 05                 ...
        inc     $0518                           ; 9499 EE 18 05                 ...
        bne     pn_div10_loop                   ; 949C D0 EF                    ..
pn_div10_ok:
        lda     $0518                           ; 949E AD 18 05                 ...
        asl     a                               ; 94A1 0A                       .
        asl     a                               ; 94A2 0A                       .
        asl     a                               ; 94A3 0A                       .
        sta     glyph_offset                    ; 94A4 8D 16 05                 ...
        bit     leading_zero_flag               ; 94A7 2C 10 05                 ,..
        bmi     pn_draw                         ; 94AA 30 09                    0.
        lda     glyph_offset                    ; 94AC AD 16 05                 ...
        beq     pn_skip                         ; 94AF F0 07                    ..
        sec                                     ; 94B1 38                       8
        ror     leading_zero_flag               ; 94B2 6E 10 05                 n..
pn_draw:jsr     draw_glyph                      ; 94B5 20 BC 94                  ..
pn_skip:dey                                     ; 94B8 88                       .
        bpl     pn_div10                        ; 94B9 10 CD                    ..
        rts                                     ; 94BB 60                       `

; ----------------------------------------------------------------------------
; draw the glyph at address (font + glyph_offset)
draw_glyph:
        sty     y_stash                         ; 94BC 8C 19 05                 ...
        lda     cursor_y                        ; 94BF AD 3A 14                 .:.
        asl     a                               ; 94C2 0A                       .
        asl     a                               ; 94C3 0A                       .
        asl     a                               ; 94C4 0A                       .
        clc                                     ; 94C5 18                       .
        adc     cursor_y                        ; 94C6 6D 3A 14                 m:.
        sta     cursor_line                     ; 94C9 8D 12 05                 ...
        sta     cur_line                        ; 94CC 8D 13 05                 ...
        clc                                     ; 94CF 18                       .
        adc     #$08                            ; 94D0 69 08                    i.
        sta     last_line                       ; 94D2 8D 14 05                 ...
dg_next_line:
        ldy     cur_line                        ; 94D5 AC 13 05                 ...
        lda     screen_hi_ptrs,y                ; 94D8 B9 00 1E                 ...
        sta     screen_ptr+1                    ; 94DB 85 C1                    ..
        lda     screen_lo_ptrs,y                ; 94DD B9 00 1D                 ...
        sta     screen_ptr                      ; 94E0 85 C0                    ..
        ldx     glyph_offset                    ; 94E2 AE 16 05                 ...
        lda     font,x                          ; 94E5 BD 0A 95                 ...
        ldy     cursor_x                        ; 94E8 AC 39 14                 .9.
        and     glyph_color_mask                ; 94EB 25 EE                    %.
        sta     (screen_ptr),y                  ; 94ED 91 C0                    ..
        inc     glyph_offset                    ; 94EF EE 16 05                 ...
        inc     cur_line                        ; 94F2 EE 13 05                 ...
        lda     cur_line                        ; 94F5 AD 13 05                 ...
        cmp     last_line                       ; 94F8 CD 14 05                 ...
        bcc     dg_next_line                    ; 94FB 90 D8                    ..
        inc     cursor_x_tmp                    ; 94FD EE 15 05                 ...
        inc     cursor_x                        ; 9500 EE 39 14                 .9.
        ldy     y_stash                         ; 9503 AC 19 05                 ...
        rts                                     ; 9506 60                       `

; ----------------------------------------------------------------------------
; 1, 10, 100 aka 10*0, 10*1, 10*2. used by print_number. last byte appears to never get read.
power_10_table:
        .byte   $01,$0A,$64                     ; 9507 01 0A 64                 ..d
; 13 4x8 glyphs, 0 thru 9, space, left & right halves of copyright symbol. 2bpp, but only one color used (11). really 3x8 as rightmost column is blank (for spacing) in all glyphs. height is the full 8 (no blanks for spacing).
font:   .byte   $FC,$CC,$CC,$CC,$CC,$CC,$CC,$FC ; 950A FC CC CC CC CC CC CC FC  ........
        .byte   $3C,$CC,$0C,$0C,$0C,$0C,$0C,$0C ; 9512 3C CC 0C 0C 0C 0C 0C 0C  <.......
        .byte   $FC,$CC,$0C,$30,$30,$C0,$C0,$FC ; 951A FC CC 0C 30 30 C0 C0 FC  ...00...
        .byte   $FC,$0C,$0C,$FC,$0C,$0C,$0C,$FC ; 9522 FC 0C 0C FC 0C 0C 0C FC  ........
        .byte   $CC,$CC,$CC,$CC,$FC,$0C,$0C,$0C ; 952A CC CC CC CC FC 0C 0C 0C  ........
        .byte   $FC,$C0,$C0,$FC,$0C,$0C,$0C,$FC ; 9532 FC C0 C0 FC 0C 0C 0C FC  ........
        .byte   $FC,$C0,$C0,$FC,$CC,$CC,$CC,$FC ; 953A FC C0 C0 FC CC CC CC FC  ........
        .byte   $FC,$0C,$0C,$30,$30,$C0,$C0,$C0 ; 9542 FC 0C 0C 30 30 C0 C0 C0  ...00...
        .byte   $FC,$CC,$CC,$30,$CC,$CC,$CC,$FC ; 954A FC CC CC 30 CC CC CC FC  ...0....
        .byte   $FC,$CC,$CC,$CC,$FC,$0C,$0C,$FC ; 9552 FC CC CC CC FC 0C 0C FC  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; 955A 00 00 00 00 00 00 00 00  ........
        .byte   $3F,$C0,$CF,$CC,$CC,$CF,$C0,$3F ; 9562 3F C0 CF CC CC CF C0 3F  ?......?
        .byte   $F0,$0C,$CC,$0C,$0C,$CC,$0C,$F0 ; 956A F0 0C CC 0C 0C CC 0C F0  ........
; uppercase, 26 4x8 glyphs but no blank column for spacing (full 4x8). also J Q Z glyphs are graphics of some kind.
font_letters:
        .byte   $3C,$C3,$C3,$C3,$FF,$C3,$C3,$C3 ; 9572 3C C3 C3 C3 FF C3 C3 C3  <.......
        .byte   $FC,$C3,$C3,$FC,$C3,$C3,$C3,$FC ; 957A FC C3 C3 FC C3 C3 C3 FC  ........
        .byte   $3F,$C0,$C0,$C0,$C0,$C0,$C0,$3F ; 9582 3F C0 C0 C0 C0 C0 C0 3F  ?......?
        .byte   $FC,$C3,$C3,$C3,$C3,$C3,$C3,$FC ; 958A FC C3 C3 C3 C3 C3 C3 FC  ........
        .byte   $FF,$C0,$C0,$FF,$C0,$C0,$C0,$FF ; 9592 FF C0 C0 FF C0 C0 C0 FF  ........
        .byte   $FF,$C0,$C0,$FF,$C0,$C0,$C0,$C0 ; 959A FF C0 C0 FF C0 C0 C0 C0  ........
        .byte   $3F,$C0,$C0,$CF,$C3,$C3,$C3,$3F ; 95A2 3F C0 C0 CF C3 C3 C3 3F  ?......?
        .byte   $C3,$C3,$C3,$FF,$C3,$C3,$C3,$C3 ; 95AA C3 C3 C3 FF C3 C3 C3 C3  ........
        .byte   $FF,$30,$30,$30,$30,$30,$30,$FF ; 95B2 FF 30 30 30 30 30 30 FF  .000000.
        .byte   $18,$18,$18,$18,$18,$19,$19,$0E ; 95BA 18 18 18 18 18 19 19 0E  ........
        .byte   $C3,$C3,$CC,$FC,$CC,$C3,$C3,$C3 ; 95C2 C3 C3 CC FC CC C3 C3 C3  ........
        .byte   $C0,$C0,$C0,$C0,$C0,$C0,$C0,$FF ; 95CA C0 C0 C0 C0 C0 C0 C0 FF  ........
        .byte   $C3,$FF,$F3,$C3,$C3,$C3,$C3,$C3 ; 95D2 C3 FF F3 C3 C3 C3 C3 C3  ........
        .byte   $C3,$F3,$F3,$FF,$CF,$CF,$C3,$C3 ; 95DA C3 F3 F3 FF CF CF C3 C3  ........
        .byte   $3C,$C3,$C3,$C3,$C3,$C3,$C3,$3C ; 95E2 3C C3 C3 C3 C3 C3 C3 3C  <......<
        .byte   $FC,$C3,$C3,$FC,$C0,$C0,$C0,$C0 ; 95EA FC C3 C3 FC C0 C0 C0 C0  ........
        .byte   $1F,$19,$19,$19,$19,$1D,$09,$17 ; 95F2 1F 19 19 19 19 1D 09 17  ........
        .byte   $FC,$C3,$C3,$FC,$CC,$CC,$C3,$C3 ; 95FA FC C3 C3 FC CC CC C3 C3  ........
        .byte   $3F,$C0,$C0,$3C,$03,$03,$03,$FC ; 9602 3F C0 C0 3C 03 03 03 FC  ?..<....
        .byte   $FF,$30,$30,$30,$30,$30,$30,$30 ; 960A FF 30 30 30 30 30 30 30  .0000000
        .byte   $C3,$C3,$C3,$C3,$C3,$C3,$C3,$3C ; 9612 C3 C3 C3 C3 C3 C3 C3 3C  .......<
        .byte   $C3,$C3,$C3,$C3,$C3,$3C,$3C,$30 ; 961A C3 C3 C3 C3 C3 3C 3C 30  .....<<0
        .byte   $C3,$C3,$C3,$C3,$F3,$F3,$FF,$CF ; 9622 C3 C3 C3 C3 F3 F3 FF CF  ........
        .byte   $C3,$C3,$C3,$3C,$3C,$C3,$C3,$C3 ; 962A C3 C3 C3 3C 3C C3 C3 C3  ...<<...
        .byte   $C3,$C3,$C3,$3C,$3C,$3C,$3C,$3C ; 9632 C3 C3 C3 3C 3C 3C 3C 3C  ...<<<<<
        .byte   $1F,$19,$08,$04,$02,$01,$19,$1F ; 963A 1F 19 08 04 02 01 19 1F  ........
; ----------------------------------------------------------------------------
; ATTACK WAVE n COMPLETED, BONUS x nnn
print_end_level_msg:
        lda     #$08                            ; 9642 A9 08                    ..
        sta     cursor_x                        ; 9644 8D 39 14                 .9.
        lda     #$06                            ; 9647 A9 06                    ..
        sta     cursor_y                        ; 9649 8D 3A 14                 .:.
        lda     #$FF                            ; 964C A9 FF                    ..
        sta     glyph_color_mask                ; 964E 85 EE                    ..
        ldy     #$00                            ; 9650 A0 00                    ..
aw_loop:lda     attack_wave_text,y              ; 9652 B9 D6 96                 ...
        beq     print_level                     ; 9655 F0 06                    ..
        jsr     printchar                       ; 9657 20 2E 97                  ..
        iny                                     ; 965A C8                       .
        bne     aw_loop                         ; 965B D0 F5                    ..
print_level:
        lda     level                           ; 965D A5 9A                    ..
        lsr     leading_zero_flag               ; 965F 4E 10 05                 N..
        jsr     print_number                    ; 9662 20 83 94                  ..
        ldy     #$00                            ; 9665 A0 00                    ..
completed_loop:
        lda     completed_text,y                ; 9667 B9 EE 96                 ...
        beq     clamp_bonus                     ; 966A F0 06                    ..
        jsr     printchar                       ; 966C 20 2E 97                  ..
        iny                                     ; 966F C8                       .
        bne     completed_loop                  ; 9670 D0 F5                    ..
; limit bonus multiplier to 5 (hundred, actually)
clamp_bonus:
        lda     level                           ; 9672 A5 9A                    ..
        cmp     #$06                            ; 9674 C9 06                    ..
        bcc     print_bonus_mult                ; 9676 90 02                    ..
        lda     #$05                            ; 9678 A9 05                    ..
; print 1st digit of bonus multiplier (range 1-5)
print_bonus_mult:
        lsr     leading_zero_flag               ; 967A 4E 10 05                 N..
        jsr     print_number                    ; 967D 20 83 94                  ..
        sec                                     ; 9680 38                       8
        ror     leading_zero_flag               ; 9681 6E 10 05                 n..
; print 00 after the 1-digit multiplier
print_bonus_00:
        lda     #$00                            ; 9684 A9 00                    ..
        jsr     print_number                    ; 9686 20 83 94                  ..
        lda     #$22                            ; 9689 A9 22                    ."
        sta     sprite_x                        ; 968B 85 E3                    ..
        lda     #$90                            ; 968D A9 90                    ..
        sta     sprite_y                        ; 968F 85 DF                    ..
        lda     #$00                            ; 9691 A9 00                    ..
        sta     $E4                             ; 9693 85 E4                    ..
        jmp     add_bonus                       ; 9695 4C A2 96                 L..

; ----------------------------------------------------------------------------
ab_next_sprite:
        lda     $E4                             ; 9698 A5 E4                    ..
        clc                                     ; 969A 18                       .
        adc     #$04                            ; 969B 69 04                    i.
        sta     $E4                             ; 969D 85 E4                    ..
        bpl     add_bonus                       ; 969F 10 01                    ..
        rts                                     ; 96A1 60                       `

; ----------------------------------------------------------------------------
; add the bonus * multiplier to the score, for remaining humanoids
add_bonus:
        ldy     $E4                             ; 96A2 A4 E4                    ..
        lda     sprite_list,y                   ; 96A4 B9 EB 0A                 ...
        beq     ab_next_sprite                  ; 96A7 F0 EF                    ..
        lda     sprite_list+3,y                 ; 96A9 B9 EE 0A                 ...
        and     #$07                            ; 96AC 29 07                    ).
        bne     ab_next_sprite                  ; 96AE D0 E8                    ..
        lda     #$00                            ; 96B0 A9 00                    ..
        sta     current_sprite                  ; 96B2 85 F9                    ..
        jsr     draw_sprite_left_copy           ; 96B4 20 00 1F                  ..
        jsr     calc_bonus_index                ; 96B7 20 C7 96                  ..
        jsr     draw_scores                     ; 96BA 20 42 94                  B.
        clc                                     ; 96BD 18                       .
        lda     sprite_x                        ; 96BE A5 E3                    ..
        adc     #$0A                            ; 96C0 69 0A                    i.
        sta     sprite_x                        ; 96C2 85 E3                    ..
        jmp     ab_next_sprite                  ; 96C4 4C 98 96                 L..

; ----------------------------------------------------------------------------
; A = 7 + (level < 6 ? level : 5); // index into score_points_table
calc_bonus_index:
        lda     level                           ; 96C7 A5 9A                    ..
        cmp     #$06                            ; 96C9 C9 06                    ..
        bcc     cbi_add7                        ; 96CB 90 02                    ..
        lda     #$05                            ; 96CD A9 05                    ..
; add 7 because that's where the bonus amounts start, in score_points_table
cbi_add7:
        clc                                     ; 96CF 18                       .
        adc     #$07                            ; 96D0 69 07                    i.
        jmp     add_points                      ; 96D2 4C B2 A7                 L..

; ----------------------------------------------------------------------------
        rts                                     ; 96D5 60                       `

; ----------------------------------------------------------------------------
attack_wave_text:
        .byte   $C1,$A0,$D4,$A0,$D4,$A0,$C1,$A0 ; 96D6 C1 A0 D4 A0 D4 A0 C1 A0  ........
        .byte   $C3,$A0,$CB,$A0,$A0,$A0,$D7,$A0 ; 96DE C3 A0 CB A0 A0 A0 D7 A0  ........
        .byte   $C1,$A0,$D6,$A0,$C5,$A0,$A0,$00 ; 96E6 C1 A0 D6 A0 C5 A0 A0 00  ........
completed_text:
        .byte   $8D,$8D,$A0,$A0,$A0,$A0,$A0,$A0 ; 96EE 8D 8D A0 A0 A0 A0 A0 A0  ........
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$C3,$A0 ; 96F6 A0 A0 A0 A0 A0 A0 C3 A0  ........
        .byte   $CF,$A0,$CD,$A0,$D0,$A0,$CC,$A0 ; 96FE CF A0 CD A0 D0 A0 CC A0  ........
        .byte   $C5,$A0,$D4,$A0,$C5,$A0,$C4,$8D ; 9706 C5 A0 D4 A0 C5 A0 C4 8D  ........
        .byte   $8D,$8D,$8D,$8D,$8D,$A0,$A0,$A0 ; 970E 8D 8D 8D 8D 8D A0 A0 A0  ........
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0 ; 9716 A0 A0 A0 A0 A0 A0 A0 A0  ........
        .byte   $A0,$C2,$A0,$CF,$A0,$CE,$A0,$D5 ; 971E A0 C2 A0 CF A0 CE A0 D5  ........
        .byte   $A0,$D3,$A0,$A0,$D8,$A0,$A0,$00 ; 9726 A0 D3 A0 A0 D8 A0 A0 00  ........
; ----------------------------------------------------------------------------
; print the DSCII text character in the A reg
printchar:
        pha                                     ; 972E 48                       H
        lda     cursor_y                        ; 972F AD 3A 14                 .:.
        asl     a                               ; 9732 0A                       .
        asl     a                               ; 9733 0A                       .
        asl     a                               ; 9734 0A                       .
        clc                                     ; 9735 18                       .
        adc     cursor_y                        ; 9736 6D 3A 14                 m:.
        sta     cursor_line                     ; 9739 8D 12 05                 ...
        lda     cursor_x                        ; 973C AD 39 14                 .9.
        sta     cursor_x_tmp                    ; 973F 8D 15 05                 ...
        pla                                     ; 9742 68                       h
        cmp     #$C0                            ; 9743 C9 C0                    ..
        beq     print_copyright                 ; 9745 F0 11                    ..
        cmp     #$8D                            ; 9747 C9 8D                    ..
        beq     print_crlf                      ; 9749 F0 1E                    ..
        cmp     #$A0                            ; 974B C9 A0                    ..
        beq     print_space                     ; 974D F0 23                    .#
        cmp     #$C1                            ; 974F C9 C1                    ..
        bcc     print_digit                     ; 9751 90 28                    .(
        cmp     #$DB                            ; 9753 C9 DB                    ..
        bcc     print_letter                    ; 9755 90 38                    .8
pch_done:
        rts                                     ; 9757 60                       `

; ----------------------------------------------------------------------------
; print copyright symbol ($c0). it's double-wide, so 2 glyphs
print_copyright:
        lda     #$58                            ; 9758 A9 58                    .X
        sta     glyph_offset                    ; 975A 8D 16 05                 ...
        jsr     draw_glyph                      ; 975D 20 BC 94                  ..
        lda     #$60                            ; 9760 A9 60                    .`
        sta     glyph_offset                    ; 9762 8D 16 05                 ...
        jsr     draw_glyph                      ; 9765 20 BC 94                  ..
        rts                                     ; 9768 60                       `

; ----------------------------------------------------------------------------
; print carriage return ($8d)
print_crlf:
        lda     #$00                            ; 9769 A9 00                    ..
        sta     cursor_x                        ; 976B 8D 39 14                 .9.
        inc     cursor_y                        ; 976E EE 3A 14                 .:.
        rts                                     ; 9771 60                       `

; ----------------------------------------------------------------------------
; print a space ($a0)
print_space:
        lda     #$50                            ; 9772 A9 50                    .P
        sta     glyph_offset                    ; 9774 8D 16 05                 ...
        jsr     draw_glyph                      ; 9777 20 BC 94                  ..
        rts                                     ; 977A 60                       `

; ----------------------------------------------------------------------------
; print a number ($b0-$ba)
print_digit:
        cmp     #$B0                            ; 977B C9 B0                    ..
        bcc     pch_done                        ; 977D 90 D8                    ..
        cmp     #$BA                            ; 977F C9 BA                    ..
        bcs     pch_done                        ; 9781 B0 D4                    ..
        and     #$0F                            ; 9783 29 0F                    ).
        asl     a                               ; 9785 0A                       .
        asl     a                               ; 9786 0A                       .
        asl     a                               ; 9787 0A                       .
        sta     glyph_offset                    ; 9788 8D 16 05                 ...
        jsr     draw_glyph                      ; 978B 20 BC 94                  ..
        rts                                     ; 978E 60                       `

; ----------------------------------------------------------------------------
; print a letter ($c1-$db). does not call draw_glyph like you might expect.
print_letter:
        sec                                     ; 978F 38                       8
        sbc     #$C1                            ; 9790 E9 C1                    ..
        asl     a                               ; 9792 0A                       .
        asl     a                               ; 9793 0A                       .
        asl     a                               ; 9794 0A                       .
        sta     glyph_offset                    ; 9795 8D 16 05                 ...
        sty     y_stash                         ; 9798 8C 19 05                 ...
        lda     cursor_line                     ; 979B AD 12 05                 ...
        sta     cur_line                        ; 979E 8D 13 05                 ...
        clc                                     ; 97A1 18                       .
        adc     #$08                            ; 97A2 69 08                    i.
        sta     last_line                       ; 97A4 8D 14 05                 ...
pl_next_line:
        ldy     cur_line                        ; 97A7 AC 13 05                 ...
        lda     screen_hi_ptrs,y                ; 97AA B9 00 1E                 ...
        sta     screen_ptr+1                    ; 97AD 85 C1                    ..
        lda     screen_lo_ptrs,y                ; 97AF B9 00 1D                 ...
        sta     screen_ptr                      ; 97B2 85 C0                    ..
        ldx     glyph_offset                    ; 97B4 AE 16 05                 ...
        lda     font_letters,x                  ; 97B7 BD 72 95                 .r.
        and     glyph_color_mask                ; 97BA 25 EE                    %.
        ldy     cursor_x_tmp                    ; 97BC AC 15 05                 ...
        sta     (screen_ptr),y                  ; 97BF 91 C0                    ..
        inc     glyph_offset                    ; 97C1 EE 16 05                 ...
        inc     cur_line                        ; 97C4 EE 13 05                 ...
        lda     cur_line                        ; 97C7 AD 13 05                 ...
        cmp     last_line                       ; 97CA CD 14 05                 ...
        bcc     pl_next_line                    ; 97CD 90 D8                    ..
        inc     cursor_x_tmp                    ; 97CF EE 15 05                 ...
        ldy     y_stash                         ; 97D2 AC 19 05                 ...
        inc     cursor_x                        ; 97D5 EE 39 14                 .9.
        rts                                     ; 97D8 60                       `

; ----------------------------------------------------------------------------
; particles
ship_explosion:
        lda     #$01                            ; 97D9 A9 01                    ..
        sta     $0501                           ; 97DB 8D 01 05                 ...
        sta     $E4                             ; 97DE 85 E4                    ..
        jsr     init_splosion                   ; 97E0 20 F7 97                  ..
        jsr     animate_explosion               ; 97E3 20 30 98                  0.
        rts                                     ; 97E6 60                       `

; ----------------------------------------------------------------------------
; looks like the ship explosion, but in reverse
hyperspace_implosion:
        lda     #$0A                            ; 97E7 A9 0A                    ..
        sta     $0501                           ; 97E9 8D 01 05                 ...
        lda     #$FF                            ; 97EC A9 FF                    ..
        sta     $E4                             ; 97EE 85 E4                    ..
        jsr     init_splosion                   ; 97F0 20 F7 97                  ..
        jsr     animate_implosion               ; 97F3 20 68 98                  h.
        rts                                     ; 97F6 60                       `

; ----------------------------------------------------------------------------
; calculate (ex|im)plosion particles for the player ship
init_splosion:
        ldx     #$00                            ; 97F7 A2 00                    ..
is_loop:jsr     get_random                      ; 97F9 20 F2 8C                  ..
        and     #$0F                            ; 97FC 29 0F                    ).
        sec                                     ; 97FE 38                       8
        sbc     #$07                            ; 97FF E9 07                    ..
        cmp     #$08                            ; 9801 C9 08                    ..
        beq     is_loop                         ; 9803 F0 F4                    ..
        sta     splosion_particles,x            ; 9805 9D 00 04                 ...
        inx                                     ; 9808 E8                       .
        bne     is_loop                         ; 9809 D0 EE                    ..
        lda     #$00                            ; 980B A9 00                    ..
        sta     $050C                           ; 980D 8D 0C 05                 ...
        lda     #$BF                            ; 9810 A9 BF                    ..
        sta     $050D                           ; 9812 8D 0D 05                 ...
        lda     #$04                            ; 9815 A9 04                    ..
        sta     $050E                           ; 9817 8D 0E 05                 ...
        lda     #$9C                            ; 981A A9 9C                    ..
        sta     $050F                           ; 981C 8D 0F 05                 ...
        lda     ship_x_pos                      ; 981F A5 C3                    ..
        clc                                     ; 9821 18                       .
        adc     #$05                            ; 9822 69 05                    i.
        sta     plosion_x_start                 ; 9824 8D 07 05                 ...
        lda     ship_y_pos                      ; 9827 A5 C4                    ..
        clc                                     ; 9829 18                       .
        adc     #$04                            ; 982A 69 04                    i.
        sta     plosion_y_start                 ; 982C 8D 08 05                 ...
        rts                                     ; 982F 60                       `

; ----------------------------------------------------------------------------
animate_explosion:
        lda     #$FF                            ; 9830 A9 FF                    ..
        sta     sprite_x                        ; 9832 85 E3                    ..
        jsr     animate_splosion                ; 9834 20 95 98                  ..
        inc     $0501                           ; 9837 EE 01 05                 ...
        jsr     animate_splosion                ; 983A 20 95 98                  ..
ae_loop:dec     $0501                           ; 983D CE 01 05                 ...
        jsr     animate_splosion                ; 9840 20 95 98                  ..
        inc     $0501                           ; 9843 EE 01 05                 ...
        inc     $0501                           ; 9846 EE 01 05                 ...
        jsr     animate_splosion                ; 9849 20 95 98                  ..
        lda     $0501                           ; 984C AD 01 05                 ...
        lsr     a                               ; 984F 4A                       J
        eor     #$0F                            ; 9850 49 0F                    I.
        ora     #$70                            ; 9852 09 70                    .p
        sta     COLOR2                          ; 9854 8D C6 02                 ...
        lda     $0501                           ; 9857 AD 01 05                 ...
        cmp     #$10                            ; 985A C9 10                    ..
        bcc     ae_loop                         ; 985C 90 DF                    ..
        jsr     animate_splosion                ; 985E 20 95 98                  ..
        dec     $0500                           ; 9861 CE 00 05                 ...
        jsr     animate_splosion                ; 9864 20 95 98                  ..
        rts                                     ; 9867 60                       `

; ----------------------------------------------------------------------------
animate_implosion:
        lda     #$FF                            ; 9868 A9 FF                    ..
        sta     sprite_x                        ; 986A 85 E3                    ..
        jsr     animate_splosion                ; 986C 20 95 98                  ..
        dec     $0501                           ; 986F CE 01 05                 ...
        jsr     animate_splosion                ; 9872 20 95 98                  ..
ai_loop:inc     $0501                           ; 9875 EE 01 05                 ...
        jsr     animate_splosion                ; 9878 20 95 98                  ..
        dec     $0501                           ; 987B CE 01 05                 ...
        dec     $0501                           ; 987E CE 01 05                 ...
        jsr     animate_splosion                ; 9881 20 95 98                  ..
        lda     $0501                           ; 9884 AD 01 05                 ...
        cmp     #$01                            ; 9887 C9 01                    ..
        bcs     ai_loop                         ; 9889 B0 EA                    ..
        jsr     animate_splosion                ; 988B 20 95 98                  ..
        inc     $0501                           ; 988E EE 01 05                 ...
        jsr     animate_splosion                ; 9891 20 95 98                  ..
        rts                                     ; 9894 60                       `

; ----------------------------------------------------------------------------
; called multiple times by animate_(im|ex)plosion. uses particles set up by init_splosion
animate_splosion:
        lda     #$00                            ; 9895 A9 00                    ..
        sta     $0509                           ; 9897 8D 09 05                 ...
L989A:  lda     $0501                           ; 989A AD 01 05                 ...
        sta     $0500                           ; 989D 8D 00 05                 ...
        inc     $0500                           ; 98A0 EE 00 05                 ...
        lda     $0509                           ; 98A3 AD 09 05                 ...
        tax                                     ; 98A6 AA                       .
        lda     splosion_particles,x            ; 98A7 BD 00 04                 ...
        sta     $0503                           ; 98AA 8D 03 05                 ...
        lda     splosion_particles+1,x          ; 98AD BD 01 04                 ...
        sta     $0504                           ; 98B0 8D 04 05                 ...
        lda     plosion_x_start                 ; 98B3 AD 07 05                 ...
        sta     plosion_x                       ; 98B6 8D 05 05                 ...
        lda     plosion_y_start                 ; 98B9 AD 08 05                 ...
        sta     plosion_y                       ; 98BC 8D 06 05                 ...
L98BF:  clc                                     ; 98BF 18                       .
        lda     $0503                           ; 98C0 AD 03 05                 ...
        adc     plosion_x                       ; 98C3 6D 05 05                 m..
        sta     plosion_x                       ; 98C6 8D 05 05                 ...
        clc                                     ; 98C9 18                       .
        lda     $0504                           ; 98CA AD 04 05                 ...
        adc     plosion_y                       ; 98CD 6D 06 05                 m..
        sta     plosion_y                       ; 98D0 8D 06 05                 ...
        dec     $0500                           ; 98D3 CE 00 05                 ...
        bne     L98BF                           ; 98D6 D0 E7                    ..
        bit     $E4                             ; 98D8 24 E4                    $.
        bmi     L98F6                           ; 98DA 30 1A                    0.
        ldy     plosion_y                       ; 98DC AC 06 05                 ...
        cpy     $050C                           ; 98DF CC 0C 05                 ...
        bcc     L9946                           ; 98E2 90 62                    .b
        cpy     $050D                           ; 98E4 CC 0D 05                 ...
        bcs     L9946                           ; 98E7 B0 5D                    .]
        ldx     plosion_x                       ; 98E9 AE 05 05                 ...
        cpx     $050E                           ; 98EC EC 0E 05                 ...
        bcc     L9946                           ; 98EF 90 55                    .U
        cpx     $050F                           ; 98F1 EC 0F 05                 ...
        bcs     L9946                           ; 98F4 B0 50                    .P
L98F6:  ldx     plosion_x                       ; 98F6 AE 05 05                 ...
        ldy     plosion_y                       ; 98F9 AC 06 05                 ...
        lda     screen_hi_ptrs,y                ; 98FC B9 00 1E                 ...
        sta     screen_ptr+1                    ; 98FF 85 C1                    ..
        lda     screen_lo_ptrs,y                ; 9901 B9 00 1D                 ...
        sta     screen_ptr                      ; 9904 85 C0                    ..
        ldy     horiz_offset_table,x            ; 9906 BC 00 1B                 ...
        lda     sprite_x                        ; 9909 A5 E3                    ..
        and     pixel_mask_table,x              ; 990B 3D 00 1C                 =..
        eor     (screen_ptr),y                  ; 990E 51 C0                    Q.
        sta     (screen_ptr),y                  ; 9910 91 C0                    ..
        lda     sprite_x                        ; 9912 A5 E3                    ..
        and     pixel_mask_table+1,x            ; 9914 3D 01 1C                 =..
        ldy     horiz_offset_table+1,x          ; 9917 BC 01 1B                 ...
        eor     (screen_ptr),y                  ; 991A 51 C0                    Q.
        sta     (screen_ptr),y                  ; 991C 91 C0                    ..
        ldy     plosion_y                       ; 991E AC 06 05                 ...
        lda     screen_hi_ptrs+1,y              ; 9921 B9 01 1E                 ...
        sta     screen_ptr+1                    ; 9924 85 C1                    ..
        lda     screen_lo_ptrs+1,y              ; 9926 B9 01 1D                 ...
        sta     screen_ptr                      ; 9929 85 C0                    ..
        ldy     horiz_offset_table,x            ; 992B BC 00 1B                 ...
        lda     sprite_x                        ; 992E A5 E3                    ..
        and     pixel_mask_table,x              ; 9930 3D 00 1C                 =..
        eor     (screen_ptr),y                  ; 9933 51 C0                    Q.
        sta     (screen_ptr),y                  ; 9935 91 C0                    ..
        lda     sprite_x                        ; 9937 A5 E3                    ..
        and     pixel_mask_table+1,x            ; 9939 3D 01 1C                 =..
        ldy     horiz_offset_table+1,x          ; 993C BC 01 1B                 ...
        eor     (screen_ptr),y                  ; 993F 51 C0                    Q.
        sta     (screen_ptr),y                  ; 9941 91 C0                    ..
        jmp     L9951                           ; 9943 4C 51 99                 LQ.

; ----------------------------------------------------------------------------
L9946:  ldx     $0509                           ; 9946 AE 09 05                 ...
        lda     #$00                            ; 9949 A9 00                    ..
        sta     splosion_particles,x            ; 994B 9D 00 04                 ...
        sta     splosion_particles+1,x          ; 994E 9D 01 04                 ...
L9951:  inc     $0509                           ; 9951 EE 09 05                 ...
        inc     $0509                           ; 9954 EE 09 05                 ...
        lda     $0509                           ; 9957 AD 09 05                 ...
        cmp     #$FA                            ; 995A C9 FA                    ..
        bcs     as_done                         ; 995C B0 03                    ..
        jmp     L989A                           ; 995E 4C 9A 98                 L..

; ----------------------------------------------------------------------------
as_done:rts                                     ; 9961 60                       `

; ----------------------------------------------------------------------------
; erase the player's rocket exhaust
erase_exhaust:
        lda     #$00                            ; 9962 A9 00                    ..
        sta     current_sprite                  ; 9964 85 F9                    ..
        lda     ship_direction                  ; 9966 A5 C5                    ..
        bmi     L9978                           ; 9968 30 0E                    0.
        lda     ship_x_pos                      ; 996A A5 C3                    ..
        sec                                     ; 996C 38                       8
        sbc     #$06                            ; 996D E9 06                    ..
        sta     sprite_x                        ; 996F 85 E3                    ..
        lda     ship_y_pos                      ; 9971 A5 C4                    ..
        sta     sprite_y                        ; 9973 85 DF                    ..
        jmp     erase_sprite                    ; 9975 4C 2C AB                 L,.

; ----------------------------------------------------------------------------
L9978:  lda     ship_x_pos                      ; 9978 A5 C3                    ..
        clc                                     ; 997A 18                       .
        adc     #$0B                            ; 997B 69 0B                    i.
        sta     sprite_x                        ; 997D 85 E3                    ..
        lda     ship_y_pos                      ; 997F A5 C4                    ..
        sta     sprite_y                        ; 9981 85 DF                    ..
        jmp     erase_sprite                    ; 9983 4C 2C AB                 L,.

; ----------------------------------------------------------------------------
; draw the player's rocket exhaust, if he's thrusting
ship_exhaust:
        bit     exhaust_flag                    ; 9986 2C 2B 0D                 ,+.
        bmi     L9994                           ; 9989 30 09                    0.
        lda     #$00                            ; 998B A9 00                    ..
        sta     AUDF2                           ; 998D 8D 02 D2                 ...
        sta     AUDC2                           ; 9990 8D 03 D2                 ...
        rts                                     ; 9993 60                       `

; ----------------------------------------------------------------------------
L9994:  lda     #$1F                            ; 9994 A9 1F                    ..
        sta     AUDF2                           ; 9996 8D 02 D2                 ...
        lda     #$82                            ; 9999 A9 82                    ..
        sta     AUDC2                           ; 999B 8D 03 D2                 ...
        lda     ship_direction                  ; 999E A5 C5                    ..
        bmi     L99B9                           ; 99A0 30 17                    0.
        lda     ship_x_pos                      ; 99A2 A5 C3                    ..
        sec                                     ; 99A4 38                       8
        sbc     #$06                            ; 99A5 E9 06                    ..
        sta     sprite_x                        ; 99A7 85 E3                    ..
        lda     ship_y_pos                      ; 99A9 A5 C4                    ..
        sta     sprite_y                        ; 99AB 85 DF                    ..
        lda     animation_counter               ; 99AD A5 85                    ..
        and     #$01                            ; 99AF 29 01                    ).
        clc                                     ; 99B1 18                       .
        adc     #$13                            ; 99B2 69 13                    i.
        sta     $88                             ; 99B4 85 88                    ..
        jmp     draw_sprite_right_copy          ; 99B6 4C 80 1F                 L..

; ----------------------------------------------------------------------------
L99B9:  lda     ship_x_pos                      ; 99B9 A5 C3                    ..
        clc                                     ; 99BB 18                       .
        adc     #$0B                            ; 99BC 69 0B                    i.
        sta     sprite_x                        ; 99BE 85 E3                    ..
        lda     ship_y_pos                      ; 99C0 A5 C4                    ..
        sta     sprite_y                        ; 99C2 85 DF                    ..
        lda     animation_counter               ; 99C4 A5 85                    ..
        and     #$01                            ; 99C6 29 01                    ).
        clc                                     ; 99C8 18                       .
        adc     #$11                            ; 99C9 69 11                    i.
        sta     $88                             ; 99CB 85 88                    ..
        jmp     draw_sprite_right_copy          ; 99CD 4C 80 1F                 L..

; ----------------------------------------------------------------------------
; trigger was pressed, decide what (if anything) to do about it
handle_trigger:
        lsr     ATRACT                          ; 99D0 46 4D                    FM
        ldy     #$00                            ; 99D2 A0 00                    ..
; look for an empty slot. if the table is full (4 shots in progress, ignore this trigger press. otherwise, Y is the byte index of the empty slot ($00, $04, $08, or $0c).
check_shot_table:
        lda     player_shots_y,y                ; 99D4 B9 1A 05                 ...
        beq     shoot                           ; 99D7 F0 0D                    ..
        tya                                     ; 99D9 98                       .
        clc                                     ; 99DA 18                       .
        adc     #$04                            ; 99DB 69 04                    i.
        tay                                     ; 99DD A8                       .
        cpy     #$10                            ; 99DE C0 10                    ..
        bcc     check_shot_table                ; 99E0 90 F2                    ..
        jsr     ram_self_destruct_1             ; 99E2 20 7F B4                  ..
        rts                                     ; 99E5 60                       `

; ----------------------------------------------------------------------------
; fire player's laser in the direction he's facing
shoot:  lda     ship_y_pos                      ; 99E6 A5 C4                    ..
        clc                                     ; 99E8 18                       .
        adc     #$05                            ; 99E9 69 05                    i.
        sta     player_shots_y,y                ; 99EB 99 1A 05                 ...
        lda     ship_x_pos                      ; 99EE A5 C3                    ..
        and     #$FC                            ; 99F0 29 FC                    ).
        ldx     ship_direction                  ; 99F2 A6 C5                    ..
        bmi     shot_left                       ; 99F4 30 06                    0.
; start position for right-facing shot
shot_right:
        clc                                     ; 99F6 18                       .
        adc     #$0C                            ; 99F7 69 0C                    i.
        jmp     set_start_pos                   ; 99F9 4C FF 99                 L..

; ----------------------------------------------------------------------------
; start position for left-facing shot
shot_left:
        sec                                     ; 99FC 38                       8
        sbc     #$04                            ; 99FD E9 04                    ..
; set start and end to same pos
set_start_pos:
        sta     player_shots_x_start,y          ; 99FF 99 1B 05                 ...
        sta     player_shots_x_end,y            ; 9A02 99 1C 05                 ...
        lda     ship_direction                  ; 9A05 A5 C5                    ..
        bmi     delta_left                      ; 9A07 30 05                    0.
; delta for shot = 2
delta_right:
        lda     #$02                            ; 9A09 A9 02                    ..
        jmp     set_delta                       ; 9A0B 4C 10 9A                 L..

; ----------------------------------------------------------------------------
; delta $FE aka -2
delta_left:
        lda     #$FE                            ; 9A0E A9 FE                    ..
set_delta:
        sta     player_shots_delta,y            ; 9A10 99 1D 05                 ...
        jsr     play_player_fire                ; 9A13 20 98 8D                  ..
        rts                                     ; 9A16 60                       `

; ----------------------------------------------------------------------------
; move and draw player shots. remove from table if they reach the end of the screen
update_player_shots:
        lda     current_player_shot             ; 9A17 A5 C2                    ..
        clc                                     ; 9A19 18                       .
        adc     #$04                            ; 9A1A 69 04                    i.
        sta     current_player_shot             ; 9A1C 85 C2                    ..
        cmp     #$10                            ; 9A1E C9 10                    ..
        bcc     L9A26                           ; 9A20 90 04                    ..
        lda     #$00                            ; 9A22 A9 00                    ..
        sta     current_player_shot             ; 9A24 85 C2                    ..
L9A26:  ldy     current_player_shot             ; 9A26 A4 C2                    ..
        lda     player_shots_y,y                ; 9A28 B9 1A 05                 ...
        bne     ups_found                       ; 9A2B D0 01                    ..
        rts                                     ; 9A2D 60                       `

; ----------------------------------------------------------------------------
ups_found:
        tax                                     ; 9A2E AA                       .
        lda     screen_hi_ptrs,x                ; 9A2F BD 00 1E                 ...
        sta     screen_ptr+1                    ; 9A32 85 C1                    ..
        lda     screen_lo_ptrs,x                ; 9A34 BD 00 1D                 ...
        sta     screen_ptr                      ; 9A37 85 C0                    ..
        lda     player_shots_x_end,y            ; 9A39 B9 1C 05                 ...
        beq     ups_erase                       ; 9A3C F0 42                    .B
        clc                                     ; 9A3E 18                       .
        adc     player_shots_delta,y            ; 9A3F 79 1D 05                 y..
        cmp     #$A0                            ; 9A42 C9 A0                    ..
        bcc     ups_store_x                     ; 9A44 90 02                    ..
        lda     #$00                            ; 9A46 A9 00                    ..
ups_store_x:
        sta     player_shots_x_end,y            ; 9A48 99 1C 05                 ...
        beq     ups_done                        ; 9A4B F0 32                    .2
        tax                                     ; 9A4D AA                       .
        ldy     horiz_offset_table,x            ; 9A4E BC 00 1B                 ...
        lda     #$FF                            ; 9A51 A9 FF                    ..
        sta     (screen_ptr),y                  ; 9A53 91 C0                    ..
        ldy     current_player_shot             ; 9A55 A4 C2                    ..
        lda     player_shots_x_end,y            ; 9A57 B9 1C 05                 ...
        sec                                     ; 9A5A 38                       8
        sbc     player_shots_x_start,y          ; 9A5B F9 1B 05                 ...
        bcs     L9A64                           ; 9A5E B0 04                    ..
        eor     #$FF                            ; 9A60 49 FF                    I.
        adc     #$01                            ; 9A62 69 01                    i.
L9A64:  cmp     #$10                            ; 9A64 C9 10                    ..
        bcc     ups_done                        ; 9A66 90 17                    ..
        lda     player_shots_x_end,y            ; 9A68 B9 1C 05                 ...
        cmp     player_shots_x_start,y          ; 9A6B D9 1B 05                 ...
        bcc     L9A75                           ; 9A6E 90 05                    ..
        sbc     #$0C                            ; 9A70 E9 0C                    ..
        jmp     L9A77                           ; 9A72 4C 77 9A                 Lw.

; ----------------------------------------------------------------------------
L9A75:  adc     #$0C                            ; 9A75 69 0C                    i.
L9A77:  tax                                     ; 9A77 AA                       .
        ldy     horiz_offset_table,x            ; 9A78 BC 00 1B                 ...
        lda     random_seed                     ; 9A7B A5 C6                    ..
        sta     (screen_ptr),y                  ; 9A7D 91 C0                    ..
ups_done:
        rts                                     ; 9A7F 60                       `

; ----------------------------------------------------------------------------
ups_erase:
        lda     player_shots_x_start,y          ; 9A80 B9 1B 05                 ...
        clc                                     ; 9A83 18                       .
        adc     player_shots_delta,y            ; 9A84 79 1D 05                 y..
        sta     player_shots_x_start,y          ; 9A87 99 1B 05                 ...
        tax                                     ; 9A8A AA                       .
        cmp     #$A0                            ; 9A8B C9 A0                    ..
        bcc     L9A94                           ; 9A8D 90 05                    ..
        lda     #$00                            ; 9A8F A9 00                    ..
        sta     player_shots_y,y                ; 9A91 99 1A 05                 ...
L9A94:  ldy     horiz_offset_table,x            ; 9A94 BC 00 1B                 ...
        lda     #$00                            ; 9A97 A9 00                    ..
        sta     (screen_ptr),y                  ; 9A99 91 C0                    ..
        rts                                     ; 9A9B 60                       `

; ----------------------------------------------------------------------------
L9A9C:  sec                                     ; 9A9C 38                       8
        lda     $DD                             ; 9A9D A5 DD                    ..
        sbc     $89                             ; 9A9F E5 89                    ..
        sta     sprite_x                        ; 9AA1 85 E3                    ..
        lda     $DE                             ; 9AA3 A5 DE                    ..
        sbc     $8A                             ; 9AA5 E5 8A                    ..
        sta     $E4                             ; 9AA7 85 E4                    ..
        bcs     L9AB7                           ; 9AA9 B0 0C                    ..
        lda     sprite_x                        ; 9AAB A5 E3                    ..
        adc     #$80                            ; 9AAD 69 80                    i.
        sta     sprite_x                        ; 9AAF 85 E3                    ..
        lda     $E4                             ; 9AB1 A5 E4                    ..
        adc     #$02                            ; 9AB3 69 02                    i.
        sta     $E4                             ; 9AB5 85 E4                    ..
L9AB7:  lda     $E4                             ; 9AB7 A5 E4                    ..
        bne     L9ACF                           ; 9AB9 D0 14                    ..
        lda     sprite_x                        ; 9ABB A5 E3                    ..
        cmp     #$A0                            ; 9ABD C9 A0                    ..
        bcs     L9ACF                           ; 9ABF B0 0E                    ..
        ldy     #$00                            ; 9AC1 A0 00                    ..
L9AC3:  lda     sprite_list,y                   ; 9AC3 B9 EB 0A                 ...
        beq     L9AD0                           ; 9AC6 F0 08                    ..
        tya                                     ; 9AC8 98                       .
        clc                                     ; 9AC9 18                       .
        adc     #$04                            ; 9ACA 69 04                    i.
        tay                                     ; 9ACC A8                       .
        bpl     L9AC3                           ; 9ACD 10 F4                    ..
L9ACF:  rts                                     ; 9ACF 60                       `

; ----------------------------------------------------------------------------
L9AD0:  inc     $BA                             ; 9AD0 E6 BA                    ..
        lda     sprite_y                        ; 9AD2 A5 DF                    ..
        sta     sprite_list,y                   ; 9AD4 99 EB 0A                 ...
        lda     $DD                             ; 9AD7 A5 DD                    ..
        sta     sprite_list+1,y                 ; 9AD9 99 EC 0A                 ...
        lda     $DE                             ; 9ADC A5 DE                    ..
        sta     sprite_list+2,y                 ; 9ADE 99 ED 0A                 ...
        lda     $94                             ; 9AE1 A5 94                    ..
        sta     sprite_list+3,y                 ; 9AE3 99 EE 0A                 ...
        lda     #$E2                            ; 9AE6 A9 E2                    ..
        sta     sprite_list+130,y               ; 9AE8 99 6D 0B                 .m.
        lda     $94                             ; 9AEB A5 94                    ..
        cmp     #$0B                            ; 9AED C9 0B                    ..
        beq     L9ACF                           ; 9AEF F0 DE                    ..
        lda     ship_y_pos                      ; 9AF1 A5 C4                    ..
        sec                                     ; 9AF3 38                       8
        sbc     sprite_y                        ; 9AF4 E5 DF                    ..
        bcs     L9B0E                           ; 9AF6 B0 16                    ..
        eor     #$FF                            ; 9AF8 49 FF                    I.
        adc     #$01                            ; 9AFA 69 01                    i.
        lsr     a                               ; 9AFC 4A                       J
        lsr     a                               ; 9AFD 4A                       J
        lsr     a                               ; 9AFE 4A                       J
        lsr     a                               ; 9AFF 4A                       J
        lsr     a                               ; 9B00 4A                       J
        adc     #$01                            ; 9B01 69 01                    i.
        eor     #$FF                            ; 9B03 49 FF                    I.
        clc                                     ; 9B05 18                       .
        adc     #$01                            ; 9B06 69 01                    i.
        sta     sprite_list+128,y               ; 9B08 99 6B 0B                 .k.
        jmp     L9B18                           ; 9B0B 4C 18 9B                 L..

; ----------------------------------------------------------------------------
L9B0E:  lsr     a                               ; 9B0E 4A                       J
        lsr     a                               ; 9B0F 4A                       J
        lsr     a                               ; 9B10 4A                       J
        lsr     a                               ; 9B11 4A                       J
        lsr     a                               ; 9B12 4A                       J
        adc     #$01                            ; 9B13 69 01                    i.
        sta     sprite_list+128,y               ; 9B15 99 6B 0B                 .k.
L9B18:  lda     current_sprite                  ; 9B18 A5 F9                    ..
        cmp     #$06                            ; 9B1A C9 06                    ..
        bne     L9B3B                           ; 9B1C D0 1D                    ..
        tya                                     ; 9B1E 98                       .
        pha                                     ; 9B1F 48                       H
        jsr     play_swarmer_taunt              ; 9B20 20 EC 8D                  ..
        pla                                     ; 9B23 68                       h
        tay                                     ; 9B24 A8                       .
        lda     ship_x_pos                      ; 9B25 A5 C3                    ..
        cmp     sprite_x                        ; 9B27 C5 E3                    ..
        bcs     L9B33                           ; 9B29 B0 08                    ..
        lda     #$FC                            ; 9B2B A9 FC                    ..
        sta     sprite_list+129,y               ; 9B2D 99 6C 0B                 .l.
        jmp     L9ACF                           ; 9B30 4C CF 9A                 L..

; ----------------------------------------------------------------------------
L9B33:  lda     #$04                            ; 9B33 A9 04                    ..
        sta     sprite_list+129,y               ; 9B35 99 6C 0B                 .l.
        jmp     L9ACF                           ; 9B38 4C CF 9A                 L..

; ----------------------------------------------------------------------------
L9B3B:  tya                                     ; 9B3B 98                       .
        pha                                     ; 9B3C 48                       H
        lda     current_sprite                  ; 9B3D A5 F9                    ..
        and     #$07                            ; 9B3F 29 07                    ).
        cmp     #$02                            ; 9B41 C9 02                    ..
        beq     L9B4B                           ; 9B43 F0 06                    ..
        jsr     play_lander_fire                ; 9B45 20 FA 8D                  ..
        jmp     L9B4E                           ; 9B48 4C 4E 9B                 LN.

; ----------------------------------------------------------------------------
L9B4B:  jsr     play_mutant_taunt               ; 9B4B 20 DE 8D                  ..
L9B4E:  pla                                     ; 9B4E 68                       h
        tay                                     ; 9B4F A8                       .
        lda     #$00                            ; 9B50 A9 00                    ..
        sta     $E5                             ; 9B52 85 E5                    ..
        lda     random_seed                     ; 9B54 A5 C6                    ..
        bpl     L9B5C                           ; 9B56 10 04                    ..
        lda     ship_delta                      ; 9B58 A5 D5                    ..
        sta     $E5                             ; 9B5A 85 E5                    ..
L9B5C:  lda     ship_x_pos                      ; 9B5C A5 C3                    ..
        sec                                     ; 9B5E 38                       8
        sbc     sprite_x                        ; 9B5F E5 E3                    ..
        bcs     L9B79                           ; 9B61 B0 16                    ..
        eor     #$FF                            ; 9B63 49 FF                    I.
        adc     #$01                            ; 9B65 69 01                    i.
        lsr     a                               ; 9B67 4A                       J
        lsr     a                               ; 9B68 4A                       J
        lsr     a                               ; 9B69 4A                       J
        lsr     a                               ; 9B6A 4A                       J
        lsr     a                               ; 9B6B 4A                       J
        adc     #$01                            ; 9B6C 69 01                    i.
        eor     #$FF                            ; 9B6E 49 FF                    I.
        clc                                     ; 9B70 18                       .
        adc     $E5                             ; 9B71 65 E5                    e.
        sta     sprite_list+129,y               ; 9B73 99 6C 0B                 .l.
        jmp     L9ACF                           ; 9B76 4C CF 9A                 L..

; ----------------------------------------------------------------------------
L9B79:  lsr     a                               ; 9B79 4A                       J
        lsr     a                               ; 9B7A 4A                       J
        lsr     a                               ; 9B7B 4A                       J
        lsr     a                               ; 9B7C 4A                       J
        lsr     a                               ; 9B7D 4A                       J
        adc     $E5                             ; 9B7E 65 E5                    e.
        sta     sprite_list+129,y               ; 9B80 99 6C 0B                 .l.
        jmp     L9ACF                           ; 9B83 4C CF 9A                 L..

; ----------------------------------------------------------------------------
spawn_enemy_shot:
        ldy     $98                             ; 9B86 A4 98                    ..
        ldx     $98                             ; 9B88 A6 98                    ..
        inc     sprite_list+130,x               ; 9B8A FE 6D 0B                 .m.
        bne     L9B9A                           ; 9B8D D0 0B                    ..
L9B8F:  lda     #$00                            ; 9B8F A9 00                    ..
        sta     sprite_y                        ; 9B91 85 DF                    ..
        lda     #$80                            ; 9B93 A9 80                    ..
        sta     $DE                             ; 9B95 85 DE                    ..
        jmp     L9BD9                           ; 9B97 4C D9 9B                 L..

; ----------------------------------------------------------------------------
L9B9A:  lda     current_sprite                  ; 9B9A A5 F9                    ..
        cmp     #$0B                            ; 9B9C C9 0B                    ..
        beq     L9BE0                           ; 9B9E F0 40                    .@
        lda     sprite_list+128,x               ; 9BA0 BD 6B 0B                 .k.
        clc                                     ; 9BA3 18                       .
        adc     sprite_y                        ; 9BA4 65 DF                    e.
        sta     sprite_y                        ; 9BA6 85 DF                    ..
        lda     sprite_y                        ; 9BA8 A5 DF                    ..
        cmp     #$20                            ; 9BAA C9 20                    . 
        bcc     L9B8F                           ; 9BAC 90 E1                    ..
        cmp     #$C0                            ; 9BAE C9 C0                    ..
        bcs     L9B8F                           ; 9BB0 B0 DD                    ..
        lda     sprite_list+129,x               ; 9BB2 BD 6C 0B                 .l.
        bmi     L9BC5                           ; 9BB5 30 0E                    0.
        clc                                     ; 9BB7 18                       .
        adc     $DD                             ; 9BB8 65 DD                    e.
        sta     $DD                             ; 9BBA 85 DD                    ..
        lda     $DE                             ; 9BBC A5 DE                    ..
        adc     #$00                            ; 9BBE 69 00                    i.
        sta     $DE                             ; 9BC0 85 DE                    ..
        jmp     L9BD9                           ; 9BC2 4C D9 9B                 L..

; ----------------------------------------------------------------------------
L9BC5:  eor     #$FF                            ; 9BC5 49 FF                    I.
        clc                                     ; 9BC7 18                       .
        adc     #$01                            ; 9BC8 69 01                    i.
        sta     sprite_x                        ; 9BCA 85 E3                    ..
        sec                                     ; 9BCC 38                       8
        lda     $DD                             ; 9BCD A5 DD                    ..
        sbc     sprite_x                        ; 9BCF E5 E3                    ..
        sta     $DD                             ; 9BD1 85 DD                    ..
        lda     $DE                             ; 9BD3 A5 DE                    ..
        sbc     #$00                            ; 9BD5 E9 00                    ..
        sta     $DE                             ; 9BD7 85 DE                    ..
L9BD9:  lda     #$0D                            ; 9BD9 A9 0D                    ..
        sta     $88                             ; 9BDB 85 88                    ..
        jmp     LA5B2                           ; 9BDD 4C B2 A5                 L..

; ----------------------------------------------------------------------------
L9BE0:  lda     #$10                            ; 9BE0 A9 10                    ..
        sta     $88                             ; 9BE2 85 88                    ..
        jmp     LA5B2                           ; 9BE4 4C B2 A5                 L..

; ----------------------------------------------------------------------------
; queue up an explosion, at first empty slot (or at last slot, if table is full)
start_enemy_explosion:
        ldy     #$00                            ; 9BE7 A0 00                    ..
see_next:
        lda     enemy_explosion_table,y         ; 9BE9 B9 2B 05                 .+.
        beq     see_queue                       ; 9BEC F0 0A                    ..
        tya                                     ; 9BEE 98                       .
        clc                                     ; 9BEF 18                       .
        adc     #$04                            ; 9BF0 69 04                    i.
        tay                                     ; 9BF2 A8                       .
        cpy     #$80                            ; 9BF3 C0 80                    ..
        bcc     see_next                        ; 9BF5 90 F2                    ..
        rts                                     ; 9BF7 60                       `

; ----------------------------------------------------------------------------
see_queue:
        lda     $CA                             ; 9BF8 A5 CA                    ..
        sta     enemy_explosion_table,y         ; 9BFA 99 2B 05                 .+.
        lda     $C9                             ; 9BFD A5 C9                    ..
        sta     enemy_explosion_table+1,y       ; 9BFF 99 2C 05                 .,.
        lda     $CB                             ; 9C02 A5 CB                    ..
        sta     enemy_explosion_table+2,y       ; 9C04 99 2D 05                 .-.
        lda     #$28                            ; 9C07 A9 28                    .(
        sta     enemy_explosion_table+3,y       ; 9C09 99 2E 05                 ...
        rts                                     ; 9C0C 60                       `

; ----------------------------------------------------------------------------
; flash screen when bomb goes off (whether any enemies are on screen or not)
smartbomb_flash:
        lda     #$20                            ; 9C0D A9 20                    . 
sbf_loop:
        pha                                     ; 9C0F 48                       H
        jsr     start_explosion                 ; 9C10 20 1A 9C                  ..
        pla                                     ; 9C13 68                       h
        sec                                     ; 9C14 38                       8
        sbc     #$01                            ; 9C15 E9 01                    ..
        bne     sbf_loop                        ; 9C17 D0 F6                    ..
        rts                                     ; 9C19 60                       `

; ----------------------------------------------------------------------------
; enemy or humanoid explosions, *not* the player's ship
start_explosion:
        lda     $CC                             ; 9C1A A5 CC                    ..
        clc                                     ; 9C1C 18                       .
        adc     #$04                            ; 9C1D 69 04                    i.
        sta     $CC                             ; 9C1F 85 CC                    ..
        cmp     #$80                            ; 9C21 C9 80                    ..
        bcc     L9C29                           ; 9C23 90 04                    ..
        lda     #$00                            ; 9C25 A9 00                    ..
        sta     $CC                             ; 9C27 85 CC                    ..
L9C29:  ldy     $CC                             ; 9C29 A4 CC                    ..
        lda     enemy_explosion_table,y         ; 9C2B B9 2B 05                 .+.
        bne     L9C31                           ; 9C2E D0 01                    ..
        rts                                     ; 9C30 60                       `

; ----------------------------------------------------------------------------
L9C31:  sta     $CA                             ; 9C31 85 CA                    ..
        lda     enemy_explosion_table+1,y       ; 9C33 B9 2C 05                 .,.
        sta     $C9                             ; 9C36 85 C9                    ..
        lda     enemy_explosion_table+2,y       ; 9C38 B9 2D 05                 .-.
        sta     $CB                             ; 9C3B 85 CB                    ..
        jsr     L9C6C                           ; 9C3D 20 6C 9C                  l.
        lda     $C9                             ; 9C40 A5 C9                    ..
        sec                                     ; 9C42 38                       8
        sbc     ship_delta                      ; 9C43 E5 D5                    ..
        sta     $C9                             ; 9C45 85 C9                    ..
        ldx     $CC                             ; 9C47 A6 CC                    ..
        sta     enemy_explosion_table+1,x       ; 9C49 9D 2C 05                 .,.
        inc     enemy_explosion_table+2,x       ; 9C4C FE 2D 05                 .-.
        inc     $CB                             ; 9C4F E6 CB                    ..
        lda     enemy_explosion_table+2,x       ; 9C51 BD 2D 05                 .-.
        cmp     enemy_explosion_table+3,x       ; 9C54 DD 2E 05                 ...
        bcc     L9C5F                           ; 9C57 90 06                    ..
        lda     #$00                            ; 9C59 A9 00                    ..
        sta     enemy_explosion_table,x         ; 9C5B 9D 2B 05                 .+.
        rts                                     ; 9C5E 60                       `

; ----------------------------------------------------------------------------
L9C5F:  jmp     L9C62                           ; 9C5F 4C 62 9C                 Lb.

; ----------------------------------------------------------------------------
L9C62:  lda     #$FF                            ; 9C62 A9 FF                    ..
        sta     $CD                             ; 9C64 85 CD                    ..
        lda     $C030                           ; 9C66 AD 30 C0                 .0.
        jmp     L9C70                           ; 9C69 4C 70 9C                 Lp.

; ----------------------------------------------------------------------------
L9C6C:  lda     #$00                            ; 9C6C A9 00                    ..
        sta     $CD                             ; 9C6E 85 CD                    ..
L9C70:  lda     $CA                             ; 9C70 A5 CA                    ..
        sec                                     ; 9C72 38                       8
        sbc     $CB                             ; 9C73 E5 CB                    ..
        tay                                     ; 9C75 A8                       .
        lda     screen_hi_ptrs,y                ; 9C76 B9 00 1E                 ...
        sta     screen_ptr+1                    ; 9C79 85 C1                    ..
        lda     screen_lo_ptrs,y                ; 9C7B B9 00 1D                 ...
        sta     screen_ptr                      ; 9C7E 85 C0                    ..
        lda     $C9                             ; 9C80 A5 C9                    ..
        sec                                     ; 9C82 38                       8
        sbc     $CB                             ; 9C83 E5 CB                    ..
        tax                                     ; 9C85 AA                       .
        ldy     horiz_offset_table,x            ; 9C86 BC 00 1B                 ...
        lda     random_seed                     ; 9C89 A5 C6                    ..
        and     $CD                             ; 9C8B 25 CD                    %.
        sta     (screen_ptr),y                  ; 9C8D 91 C0                    ..
        ldx     $C9                             ; 9C8F A6 C9                    ..
        ldy     horiz_offset_table,x            ; 9C91 BC 00 1B                 ...
        lda     random_seed                     ; 9C94 A5 C6                    ..
        and     $CD                             ; 9C96 25 CD                    %.
        sta     (screen_ptr),y                  ; 9C98 91 C0                    ..
        lda     $C9                             ; 9C9A A5 C9                    ..
        clc                                     ; 9C9C 18                       .
        adc     $CB                             ; 9C9D 65 CB                    e.
        tax                                     ; 9C9F AA                       .
        ldy     horiz_offset_table,x            ; 9CA0 BC 00 1B                 ...
        lda     random_seed                     ; 9CA3 A5 C6                    ..
        and     $CD                             ; 9CA5 25 CD                    %.
        sta     (screen_ptr),y                  ; 9CA7 91 C0                    ..
        ldy     $CA                             ; 9CA9 A4 CA                    ..
        lda     screen_hi_ptrs,y                ; 9CAB B9 00 1E                 ...
        sta     screen_ptr+1                    ; 9CAE 85 C1                    ..
        lda     screen_lo_ptrs,y                ; 9CB0 B9 00 1D                 ...
        sta     screen_ptr                      ; 9CB3 85 C0                    ..
        lda     $C9                             ; 9CB5 A5 C9                    ..
        sec                                     ; 9CB7 38                       8
        sbc     $CB                             ; 9CB8 E5 CB                    ..
        tax                                     ; 9CBA AA                       .
        ldy     horiz_offset_table,x            ; 9CBB BC 00 1B                 ...
        lda     random_seed                     ; 9CBE A5 C6                    ..
        and     $CD                             ; 9CC0 25 CD                    %.
        sta     (screen_ptr),y                  ; 9CC2 91 C0                    ..
        ldx     $C9                             ; 9CC4 A6 C9                    ..
        ldy     horiz_offset_table,x            ; 9CC6 BC 00 1B                 ...
        lda     random_seed                     ; 9CC9 A5 C6                    ..
        and     $CD                             ; 9CCB 25 CD                    %.
        sta     (screen_ptr),y                  ; 9CCD 91 C0                    ..
        lda     $C9                             ; 9CCF A5 C9                    ..
        clc                                     ; 9CD1 18                       .
        adc     $CB                             ; 9CD2 65 CB                    e.
        tax                                     ; 9CD4 AA                       .
        ldy     horiz_offset_table,x            ; 9CD5 BC 00 1B                 ...
        lda     random_seed                     ; 9CD8 A5 C6                    ..
        and     $CD                             ; 9CDA 25 CD                    %.
        sta     (screen_ptr),y                  ; 9CDC 91 C0                    ..
        lda     $CA                             ; 9CDE A5 CA                    ..
        clc                                     ; 9CE0 18                       .
        adc     $CB                             ; 9CE1 65 CB                    e.
        tay                                     ; 9CE3 A8                       .
        lda     screen_hi_ptrs,y                ; 9CE4 B9 00 1E                 ...
        sta     screen_ptr+1                    ; 9CE7 85 C1                    ..
        lda     screen_lo_ptrs,y                ; 9CE9 B9 00 1D                 ...
        sta     screen_ptr                      ; 9CEC 85 C0                    ..
        lda     $C9                             ; 9CEE A5 C9                    ..
        sec                                     ; 9CF0 38                       8
        sbc     $CB                             ; 9CF1 E5 CB                    ..
        tax                                     ; 9CF3 AA                       .
        ldy     horiz_offset_table,x            ; 9CF4 BC 00 1B                 ...
        lda     random_seed                     ; 9CF7 A5 C6                    ..
        and     $CD                             ; 9CF9 25 CD                    %.
        sta     (screen_ptr),y                  ; 9CFB 91 C0                    ..
        ldx     $C9                             ; 9CFD A6 C9                    ..
        ldy     horiz_offset_table,x            ; 9CFF BC 00 1B                 ...
        lda     random_seed                     ; 9D02 A5 C6                    ..
        and     $CD                             ; 9D04 25 CD                    %.
        sta     (screen_ptr),y                  ; 9D06 91 C0                    ..
        lda     $C9                             ; 9D08 A5 C9                    ..
        clc                                     ; 9D0A 18                       .
        adc     $CB                             ; 9D0B 65 CB                    e.
        tax                                     ; 9D0D AA                       .
        ldy     horiz_offset_table,x            ; 9D0E BC 00 1B                 ...
        lda     random_seed                     ; 9D11 A5 C6                    ..
        and     $CD                             ; 9D13 25 CD                    %.
        sta     (screen_ptr),y                  ; 9D15 91 C0                    ..
        rts                                     ; 9D17 60                       `

; ----------------------------------------------------------------------------
L9D18:  lda     #$A0                            ; 9D18 A9 A0                    ..
        sta     $D3                             ; 9D1A 85 D3                    ..
        ldy     #$00                            ; 9D1C A0 00                    ..
L9D1E:  sta     $05AB,y                         ; 9D1E 99 AB 05                 ...
        sta     $06AB,y                         ; 9D21 99 AB 06                 ...
        sta     $072B,y                         ; 9D24 99 2B 07                 .+.
        sta     $082B,y                         ; 9D27 99 2B 08                 .+.
        sta     $092B,y                         ; 9D2A 99 2B 09                 .+.
        sta     $09AB,y                         ; 9D2D 99 AB 09                 ...
        iny                                     ; 9D30 C8                       .
        bne     L9D1E                           ; 9D31 D0 EB                    ..
        lda     #$05                            ; 9D33 A9 05                    ..
        sta     $D0                             ; 9D35 85 D0                    ..
        lda     #$AB                            ; 9D37 A9 AB                    ..
        sta     $CF                             ; 9D39 85 CF                    ..
L9D3B:  jsr     get_random                      ; 9D3B 20 F2 8C                  ..
        cmp     #$D8                            ; 9D3E C9 D8                    ..
        bcs     L9DAB                           ; 9D40 B0 69                    .i
        ldx     #$01                            ; 9D42 A2 01                    ..
L9D44:  dec     $D3                             ; 9D44 C6 D3                    ..
        lda     $D3                             ; 9D46 A5 D3                    ..
        ldy     #$00                            ; 9D48 A0 00                    ..
        sta     ($CF),y                         ; 9D4A 91 CF                    ..
        jsr     L9D8E                           ; 9D4C 20 8E 9D                  ..
        bcs     L9D62                           ; 9D4F B0 11                    ..
        inc     $D3                             ; 9D51 E6 D3                    ..
        lda     $D3                             ; 9D53 A5 D3                    ..
        sta     ($CF),y                         ; 9D55 91 CF                    ..
        jsr     L9D8E                           ; 9D57 20 8E 9D                  ..
        bcs     L9D62                           ; 9D5A B0 06                    ..
        dex                                     ; 9D5C CA                       .
        bne     L9D44                           ; 9D5D D0 E5                    ..
        jmp     L9D3B                           ; 9D5F 4C 3B 9D                 L;.

; ----------------------------------------------------------------------------
L9D62:  ldy     #$00                            ; 9D62 A0 00                    ..
L9D64:  jsr     L9D9D                           ; 9D64 20 9D 9D                  ..
        lda     ($CF),y                         ; 9D67 B1 CF                    ..
        cmp     #$A0                            ; 9D69 C9 A0                    ..
        bne     L9D64                           ; 9D6B D0 F7                    ..
L9D6D:  lda     #$A0                            ; 9D6D A9 A0                    ..
        sta     ($CF),y                         ; 9D6F 91 CF                    ..
        jsr     L9D8E                           ; 9D71 20 8E 9D                  ..
        bcc     L9D6D                           ; 9D74 90 F7                    ..
        ldx     #$00                            ; 9D76 A2 00                    ..
L9D78:  lda     $05AB,x                         ; 9D78 BD AB 05                 ...
        sta     $082B,x                         ; 9D7B 9D 2B 08                 .+.
        lda     $06AB,x                         ; 9D7E BD AB 06                 ...
        sta     $092B,x                         ; 9D81 9D 2B 09                 .+.
        lda     $072B,x                         ; 9D84 BD 2B 07                 .+.
        sta     $09AB,x                         ; 9D87 9D AB 09                 ...
        inx                                     ; 9D8A E8                       .
        bne     L9D78                           ; 9D8B D0 EB                    ..
        rts                                     ; 9D8D 60                       `

; ----------------------------------------------------------------------------
L9D8E:  inc     $CF                             ; 9D8E E6 CF                    ..
        bne     L9D94                           ; 9D90 D0 02                    ..
        inc     $D0                             ; 9D92 E6 D0                    ..
L9D94:  lda     $CF                             ; 9D94 A5 CF                    ..
        cmp     #$2B                            ; 9D96 C9 2B                    .+
        lda     $D0                             ; 9D98 A5 D0                    ..
        sbc     #$08                            ; 9D9A E9 08                    ..
        rts                                     ; 9D9C 60                       `

; ----------------------------------------------------------------------------
L9D9D:  sec                                     ; 9D9D 38                       8
        lda     $CF                             ; 9D9E A5 CF                    ..
        sbc     #$01                            ; 9DA0 E9 01                    ..
        sta     $CF                             ; 9DA2 85 CF                    ..
        lda     $D0                             ; 9DA4 A5 D0                    ..
        sbc     #$00                            ; 9DA6 E9 00                    ..
        sta     $D0                             ; 9DA8 85 D0                    ..
        rts                                     ; 9DAA 60                       `

; ----------------------------------------------------------------------------
L9DAB:  jsr     get_random                      ; 9DAB 20 F2 8C                  ..
        bmi     L9DDD                           ; 9DAE 30 2D                    0-
        lda     random_seed                     ; 9DB0 A5 C6                    ..
        and     #$1F                            ; 9DB2 29 1F                    ).
        adc     #$02                            ; 9DB4 69 02                    i.
        sta     $D1                             ; 9DB6 85 D1                    ..
        pha                                     ; 9DB8 48                       H
L9DB9:  dec     $D3                             ; 9DB9 C6 D3                    ..
        lda     $D3                             ; 9DBB A5 D3                    ..
        ldy     #$00                            ; 9DBD A0 00                    ..
        sta     ($CF),y                         ; 9DBF 91 CF                    ..
        jsr     L9D8E                           ; 9DC1 20 8E 9D                  ..
        dec     $D1                             ; 9DC4 C6 D1                    ..
        bne     L9DB9                           ; 9DC6 D0 F1                    ..
        pla                                     ; 9DC8 68                       h
        sta     $D1                             ; 9DC9 85 D1                    ..
L9DCB:  inc     $D3                             ; 9DCB E6 D3                    ..
        lda     $D3                             ; 9DCD A5 D3                    ..
        ldy     #$00                            ; 9DCF A0 00                    ..
        sta     ($CF),y                         ; 9DD1 91 CF                    ..
        jsr     L9D8E                           ; 9DD3 20 8E 9D                  ..
        dec     $D1                             ; 9DD6 C6 D1                    ..
        bne     L9DCB                           ; 9DD8 D0 F1                    ..
        jmp     L9D3B                           ; 9DDA 4C 3B 9D                 L;.

; ----------------------------------------------------------------------------
L9DDD:  lda     random_seed                     ; 9DDD A5 C6                    ..
        and     #$07                            ; 9DDF 29 07                    ).
        adc     #$02                            ; 9DE1 69 02                    i.
        sta     $D1                             ; 9DE3 85 D1                    ..
        pha                                     ; 9DE5 48                       H
L9DE6:  inc     $D3                             ; 9DE6 E6 D3                    ..
        lda     $D3                             ; 9DE8 A5 D3                    ..
        ldy     #$00                            ; 9DEA A0 00                    ..
        sta     ($CF),y                         ; 9DEC 91 CF                    ..
        jsr     L9D8E                           ; 9DEE 20 8E 9D                  ..
        dec     $D1                             ; 9DF1 C6 D1                    ..
        bne     L9DE6                           ; 9DF3 D0 F1                    ..
        pla                                     ; 9DF5 68                       h
        sta     $D1                             ; 9DF6 85 D1                    ..
L9DF8:  dec     $D3                             ; 9DF8 C6 D3                    ..
        lda     $D3                             ; 9DFA A5 D3                    ..
        ldy     #$00                            ; 9DFC A0 00                    ..
        sta     ($CF),y                         ; 9DFE 91 CF                    ..
        jsr     L9D8E                           ; 9E00 20 8E 9D                  ..
        dec     $D1                             ; 9E03 C6 D1                    ..
        bne     L9DF8                           ; 9E05 D0 F1                    ..
        jmp     L9D3B                           ; 9E07 4C 3B 9D                 L;.

; ----------------------------------------------------------------------------
; planet explosion sequence. doesn't set planet_dead_flag (that's done by the caller, after this returns)
destroy_planet:
        lda     $CF                             ; 9E0A A5 CF                    ..
        sta     tmp_ptr                         ; 9E0C 85 E7                    ..
        lda     $D0                             ; 9E0E A5 D0                    ..
        sta     tmp_ptr+1                       ; 9E10 85 E8                    ..
        lda     #$00                            ; 9E12 A9 00                    ..
        sta     $C9                             ; 9E14 85 C9                    ..
        lda     #$10                            ; 9E16 A9 10                    ..
L9E18:  pha                                     ; 9E18 48                       H
L9E19:  bit     draw_ok_flag                    ; 9E19 24 AB                    $.
        bmi     L9E19                           ; 9E1B 30 FC                    0.
L9E1D:  bit     draw_ok_flag                    ; 9E1D 24 AB                    $.
        bpl     L9E1D                           ; 9E1F 10 FC                    ..
        jsr     smartbomb_flash                 ; 9E21 20 0D 9C                  ..
        lda     COLOR4                          ; 9E24 AD C8 02                 ...
        eor     #$0F                            ; 9E27 49 0F                    I.
        sta     COLOR4                          ; 9E29 8D C8 02                 ...
        clc                                     ; 9E2C 18                       .
        lda     tmp_ptr                         ; 9E2D A5 E7                    ..
        adc     #$10                            ; 9E2F 69 10                    i.
        sta     tmp_ptr                         ; 9E31 85 E7                    ..
        lda     tmp_ptr+1                       ; 9E33 A5 E8                    ..
        adc     #$00                            ; 9E35 69 00                    i.
        sta     tmp_ptr+1                       ; 9E37 85 E8                    ..
        ldy     #$00                            ; 9E39 A0 00                    ..
        lda     (tmp_ptr),y                     ; 9E3B B1 E7                    ..
        sta     $CA                             ; 9E3D 85 CA                    ..
        clc                                     ; 9E3F 18                       .
        lda     $C9                             ; 9E40 A5 C9                    ..
        adc     #$10                            ; 9E42 69 10                    i.
        sta     $C9                             ; 9E44 85 C9                    ..
        lda     #$01                            ; 9E46 A9 01                    ..
        sta     $CB                             ; 9E48 85 CB                    ..
        jsr     start_enemy_explosion           ; 9E4A 20 E7 9B                  ..
        pla                                     ; 9E4D 68                       h
        sec                                     ; 9E4E 38                       8
        sbc     #$01                            ; 9E4F E9 01                    ..
        bne     L9E18                           ; 9E51 D0 C5                    ..
        lda     #$00                            ; 9E53 A9 00                    ..
        sta     COLOR4                          ; 9E55 8D C8 02                 ...
        jsr     play_planet_explode             ; 9E58 20 78 8E                  x.
        jmp     L9F90                           ; 9E5B 4C 90 9F                 L..

; ----------------------------------------------------------------------------
; XXX don't know how this works yet
clear_scanner_draw_planet_and_humans:
        lda     $CF                             ; 9E5E A5 CF                    ..
        sta     $FC                             ; 9E60 85 FC                    ..
        lda     $D0                             ; 9E62 A5 D0                    ..
        sta     $FD                             ; 9E64 85 FD                    ..
        sec                                     ; 9E66 38                       8
        lda     $FC                             ; 9E67 A5 FC                    ..
        sbc     #$AB                            ; 9E69 E9 AB                    ..
        sta     $8B                             ; 9E6B 85 8B                    ..
        lda     $FD                             ; 9E6D A5 FD                    ..
        sbc     #$05                            ; 9E6F E9 05                    ..
        sta     $8C                             ; 9E71 85 8C                    ..
        lda     ship_delta                      ; 9E73 A5 D5                    ..
        bpl     L9E92                           ; 9E75 10 1B                    ..
        pha                                     ; 9E77 48                       H
        eor     #$FF                            ; 9E78 49 FF                    I.
        clc                                     ; 9E7A 18                       .
        adc     #$01                            ; 9E7B 69 01                    i.
        sta     ship_delta                      ; 9E7D 85 D5                    ..
        sec                                     ; 9E7F 38                       8
        lda     $CF                             ; 9E80 A5 CF                    ..
        sbc     ship_delta                      ; 9E82 E5 D5                    ..
        sta     $CF                             ; 9E84 85 CF                    ..
        lda     $D0                             ; 9E86 A5 D0                    ..
        sbc     #$00                            ; 9E88 E9 00                    ..
        sta     $D0                             ; 9E8A 85 D0                    ..
        pla                                     ; 9E8C 68                       h
        sta     ship_delta                      ; 9E8D 85 D5                    ..
        jmp     L9E9F                           ; 9E8F 4C 9F 9E                 L..

; ----------------------------------------------------------------------------
L9E92:  clc                                     ; 9E92 18                       .
        lda     ship_delta                      ; 9E93 A5 D5                    ..
        adc     $CF                             ; 9E95 65 CF                    e.
        sta     $CF                             ; 9E97 85 CF                    ..
        lda     $D0                             ; 9E99 A5 D0                    ..
        adc     #$00                            ; 9E9B 69 00                    i.
        sta     $D0                             ; 9E9D 85 D0                    ..
L9E9F:  lda     $CF                             ; 9E9F A5 CF                    ..
        cmp     #$AB                            ; 9EA1 C9 AB                    ..
        lda     $D0                             ; 9EA3 A5 D0                    ..
        sbc     #$05                            ; 9EA5 E9 05                    ..
        bcc     L9EC3                           ; 9EA7 90 1A                    ..
        lda     $CF                             ; 9EA9 A5 CF                    ..
        cmp     #$2B                            ; 9EAB C9 2B                    .+
        lda     $D0                             ; 9EAD A5 D0                    ..
        sbc     #$08                            ; 9EAF E9 08                    ..
        bcc     L9ED0                           ; 9EB1 90 1D                    ..
        sec                                     ; 9EB3 38                       8
        lda     $CF                             ; 9EB4 A5 CF                    ..
        sbc     #$80                            ; 9EB6 E9 80                    ..
        sta     $CF                             ; 9EB8 85 CF                    ..
        lda     $D0                             ; 9EBA A5 D0                    ..
        sbc     #$02                            ; 9EBC E9 02                    ..
        sta     $D0                             ; 9EBE 85 D0                    ..
        jmp     L9ED0                           ; 9EC0 4C D0 9E                 L..

; ----------------------------------------------------------------------------
L9EC3:  clc                                     ; 9EC3 18                       .
        lda     $CF                             ; 9EC4 A5 CF                    ..
        adc     #$80                            ; 9EC6 69 80                    i.
        sta     $CF                             ; 9EC8 85 CF                    ..
        lda     $D0                             ; 9ECA A5 D0                    ..
        adc     #$02                            ; 9ECC 69 02                    i.
        sta     $D0                             ; 9ECE 85 D0                    ..
L9ED0:  sec                                     ; 9ED0 38                       8
        lda     $CF                             ; 9ED1 A5 CF                    ..
        sbc     #$AB                            ; 9ED3 E9 AB                    ..
        sta     $89                             ; 9ED5 85 89                    ..
        lda     $D0                             ; 9ED7 A5 D0                    ..
        sbc     #$05                            ; 9ED9 E9 05                    ..
        sta     $8A                             ; 9EDB 85 8A                    ..
        lda     $D7                             ; 9EDD A5 D7                    ..
        sta     $D9                             ; 9EDF 85 D9                    ..
        lda     $D8                             ; 9EE1 A5 D8                    ..
        sta     $DA                             ; 9EE3 85 DA                    ..
        sec                                     ; 9EE5 38                       8
        lda     $D9                             ; 9EE6 A5 D9                    ..
        sbc     #$AB                            ; 9EE8 E9 AB                    ..
        sta     $8F                             ; 9EEA 85 8F                    ..
        lda     $DA                             ; 9EEC A5 DA                    ..
        sbc     #$05                            ; 9EEE E9 05                    ..
        sta     $90                             ; 9EF0 85 90                    ..
        lda     $CF                             ; 9EF2 A5 CF                    ..
        sec                                     ; 9EF4 38                       8
        sbc     #$F0                            ; 9EF5 E9 F0                    ..
        sta     $D7                             ; 9EF7 85 D7                    ..
        lda     $D0                             ; 9EF9 A5 D0                    ..
        sbc     #$00                            ; 9EFB E9 00                    ..
        sta     $D8                             ; 9EFD 85 D8                    ..
        lda     $D7                             ; 9EFF A5 D7                    ..
        cmp     #$AB                            ; 9F01 C9 AB                    ..
        lda     $D8                             ; 9F03 A5 D8                    ..
        sbc     #$05                            ; 9F05 E9 05                    ..
        bcc     L9F23                           ; 9F07 90 1A                    ..
        lda     $D7                             ; 9F09 A5 D7                    ..
        cmp     #$2B                            ; 9F0B C9 2B                    .+
        lda     $D8                             ; 9F0D A5 D8                    ..
        sbc     #$08                            ; 9F0F E9 08                    ..
        bcc     L9F30                           ; 9F11 90 1D                    ..
        sec                                     ; 9F13 38                       8
        lda     $D7                             ; 9F14 A5 D7                    ..
        sbc     #$80                            ; 9F16 E9 80                    ..
        sta     $D7                             ; 9F18 85 D7                    ..
        lda     $D8                             ; 9F1A A5 D8                    ..
        sbc     #$02                            ; 9F1C E9 02                    ..
        sta     $D8                             ; 9F1E 85 D8                    ..
        jmp     L9F30                           ; 9F20 4C 30 9F                 L0.

; ----------------------------------------------------------------------------
L9F23:  clc                                     ; 9F23 18                       .
        lda     $D7                             ; 9F24 A5 D7                    ..
        adc     #$80                            ; 9F26 69 80                    i.
        sta     $D7                             ; 9F28 85 D7                    ..
        lda     $D8                             ; 9F2A A5 D8                    ..
        adc     #$02                            ; 9F2C 69 02                    i.
        sta     $D8                             ; 9F2E 85 D8                    ..
L9F30:  sec                                     ; 9F30 38                       8
        lda     $D7                             ; 9F31 A5 D7                    ..
        sbc     #$AB                            ; 9F33 E9 AB                    ..
        sta     $8D                             ; 9F35 85 8D                    ..
        lda     $D8                             ; 9F37 A5 D8                    ..
        sbc     #$05                            ; 9F39 E9 05                    ..
        sta     $8E                             ; 9F3B 85 8E                    ..
        lda     planet_dead_flag                ; 9F3D A5 A0                    ..
        bmi     L9F44                           ; 9F3F 30 03                    0.
        jmp     L9F45                           ; 9F41 4C 45 9F                 LE.

; ----------------------------------------------------------------------------
L9F44:  rts                                     ; 9F44 60                       `

; ----------------------------------------------------------------------------
L9F45:  lda     $FC                             ; 9F45 A5 FC                    ..
        sta     tmp_ptr                         ; 9F47 85 E7                    ..
        lda     $FD                             ; 9F49 A5 FD                    ..
        sta     tmp_ptr+1                       ; 9F4B 85 E8                    ..
        lda     #$A0                            ; 9F4D A9 A0                    ..
        sta     $D2                             ; 9F4F 85 D2                    ..
L9F51:  ldy     $D2                             ; 9F51 A4 D2                    ..
        lda     (tmp_ptr),y                     ; 9F53 B1 E7                    ..
        tax                                     ; 9F55 AA                       .
        lda     $1DFF,x                         ; 9F56 BD FF 1D                 ...
        sta     screen_ptr+1                    ; 9F59 85 C1                    ..
        lda     pixel_mask_table+255,x          ; 9F5B BD FF 1C                 ...
        sta     screen_ptr                      ; 9F5E 85 C0                    ..
        ldx     $D2                             ; 9F60 A6 D2                    ..
        ldy     $1AFF,x                         ; 9F62 BC FF 1A                 ...
        lda     horiz_offset_table+255,x        ; 9F65 BD FF 1B                 ...
        eor     #$FF                            ; 9F68 49 FF                    I.
        and     (screen_ptr),y                  ; 9F6A 31 C0                    1.
        sta     (screen_ptr),y                  ; 9F6C 91 C0                    ..
        ldy     $D2                             ; 9F6E A4 D2                    ..
        lda     ($CF),y                         ; 9F70 B1 CF                    ..
        tax                                     ; 9F72 AA                       .
        lda     $1DFF,x                         ; 9F73 BD FF 1D                 ...
        sta     screen_ptr+1                    ; 9F76 85 C1                    ..
        lda     pixel_mask_table+255,x          ; 9F78 BD FF 1C                 ...
        sta     screen_ptr                      ; 9F7B 85 C0                    ..
        ldx     $D2                             ; 9F7D A6 D2                    ..
        lda     #$AA                            ; 9F7F A9 AA                    ..
        and     horiz_offset_table+255,x        ; 9F81 3D FF 1B                 =..
        ldy     $1AFF,x                         ; 9F84 BC FF 1A                 ...
        ora     (screen_ptr),y                  ; 9F87 11 C0                    ..
        sta     (screen_ptr),y                  ; 9F89 91 C0                    ..
        dec     $D2                             ; 9F8B C6 D2                    ..
        bne     L9F51                           ; 9F8D D0 C2                    ..
        rts                                     ; 9F8F 60                       `

; ----------------------------------------------------------------------------
L9F90:  lda     #$A0                            ; 9F90 A9 A0                    ..
        sta     $D2                             ; 9F92 85 D2                    ..
L9F94:  ldy     $D2                             ; 9F94 A4 D2                    ..
        lda     ($CF),y                         ; 9F96 B1 CF                    ..
        tax                                     ; 9F98 AA                       .
        lda     $1DFF,x                         ; 9F99 BD FF 1D                 ...
        sta     screen_ptr+1                    ; 9F9C 85 C1                    ..
        lda     pixel_mask_table+255,x          ; 9F9E BD FF 1C                 ...
        sta     screen_ptr                      ; 9FA1 85 C0                    ..
        tya                                     ; 9FA3 98                       .
        tax                                     ; 9FA4 AA                       .
        ldy     $1AFF,x                         ; 9FA5 BC FF 1A                 ...
        lda     #$00                            ; 9FA8 A9 00                    ..
        sta     (screen_ptr),y                  ; 9FAA 91 C0                    ..
        dec     $D2                             ; 9FAC C6 D2                    ..
        bne     L9F94                           ; 9FAE D0 E4                    ..
        rts                                     ; 9FB0 60                       `

; ----------------------------------------------------------------------------
; XXX don't know how this works yet (the planet in the scanner here!)
draw_scanner_border_and_planet:
        lda     planet_dead_flag                ; 9FB1 A5 A0                    ..
        bpl     L9FB8                           ; 9FB3 10 03                    ..
        jmp     LA039                           ; 9FB5 4C 39 A0                 L9.

; ----------------------------------------------------------------------------
L9FB8:  lda     $FE                             ; 9FB8 A5 FE                    ..
        sta     tmp_ptr                         ; 9FBA 85 E7                    ..
        lda     $FF                             ; 9FBC A5 FF                    ..
        sta     tmp_ptr+1                       ; 9FBE 85 E8                    ..
        lda     #$28                            ; 9FC0 A9 28                    .(
        sta     $DB                             ; 9FC2 85 DB                    ..
        lda     #$50                            ; 9FC4 A9 50                    .P
        sta     $DC                             ; 9FC6 85 DC                    ..
L9FC8:  ldy     #$00                            ; 9FC8 A0 00                    ..
        lda     (tmp_ptr),y                     ; 9FCA B1 E7                    ..
        lsr     a                               ; 9FCC 4A                       J
        lsr     a                               ; 9FCD 4A                       J
        lsr     a                               ; 9FCE 4A                       J
        tay                                     ; 9FCF A8                       .
        lda     screen_hi_ptrs,y                ; 9FD0 B9 00 1E                 ...
        sta     screen_ptr+1                    ; 9FD3 85 C1                    ..
        lda     screen_lo_ptrs,y                ; 9FD5 B9 00 1D                 ...
        sta     screen_ptr                      ; 9FD8 85 C0                    ..
        ldx     $DB                             ; 9FDA A6 DB                    ..
        ldy     horiz_offset_table,x            ; 9FDC BC 00 1B                 ...
        lda     #$00                            ; 9FDF A9 00                    ..
        sta     (screen_ptr),y                  ; 9FE1 91 C0                    ..
        inc     $DB                             ; 9FE3 E6 DB                    ..
        clc                                     ; 9FE5 18                       .
        lda     tmp_ptr                         ; 9FE6 A5 E7                    ..
        adc     #$08                            ; 9FE8 69 08                    i.
        sta     tmp_ptr                         ; 9FEA 85 E7                    ..
        bcc     L9FF0                           ; 9FEC 90 02                    ..
        inc     tmp_ptr+1                       ; 9FEE E6 E8                    ..
L9FF0:  dec     $DC                             ; 9FF0 C6 DC                    ..
        bne     L9FC8                           ; 9FF2 D0 D4                    ..
        lda     $D7                             ; 9FF4 A5 D7                    ..
        sta     tmp_ptr                         ; 9FF6 85 E7                    ..
        sta     $FE                             ; 9FF8 85 FE                    ..
        lda     $D8                             ; 9FFA A5 D8                    ..
        sta     tmp_ptr+1                       ; 9FFC 85 E8                    ..
        sta     $FF                             ; 9FFE 85 FF                    ..
        lda     #$28                            ; A000 A9 28                    .(
        sta     $DB                             ; A002 85 DB                    ..
        lda     #$50                            ; A004 A9 50                    .P
        sta     $DC                             ; A006 85 DC                    ..
LA008:  ldy     #$00                            ; A008 A0 00                    ..
        lda     (tmp_ptr),y                     ; A00A B1 E7                    ..
        lsr     a                               ; A00C 4A                       J
        lsr     a                               ; A00D 4A                       J
        lsr     a                               ; A00E 4A                       J
        tay                                     ; A00F A8                       .
        lda     screen_hi_ptrs,y                ; A010 B9 00 1E                 ...
        sta     screen_ptr+1                    ; A013 85 C1                    ..
        lda     screen_lo_ptrs,y                ; A015 B9 00 1D                 ...
        sta     screen_ptr                      ; A018 85 C0                    ..
        ldx     $DB                             ; A01A A6 DB                    ..
        ldy     horiz_offset_table,x            ; A01C BC 00 1B                 ...
        lda     #$55                            ; A01F A9 55                    .U
        and     pixel_mask_table,x              ; A021 3D 00 1C                 =..
        ora     (screen_ptr),y                  ; A024 11 C0                    ..
        sta     (screen_ptr),y                  ; A026 91 C0                    ..
        inc     $DB                             ; A028 E6 DB                    ..
        clc                                     ; A02A 18                       .
        lda     tmp_ptr                         ; A02B A5 E7                    ..
        adc     #$08                            ; A02D 69 08                    i.
        sta     tmp_ptr                         ; A02F 85 E7                    ..
        bcc     LA035                           ; A031 90 02                    ..
        inc     tmp_ptr+1                       ; A033 E6 E8                    ..
LA035:  dec     $DC                             ; A035 C6 DC                    ..
        bne     LA008                           ; A037 D0 CF                    ..
LA039:  lda     level                           ; A039 A5 9A                    ..
        and     #$03                            ; A03B 29 03                    ).
        tay                                     ; A03D A8                       .
        lda     scanner_border_table,y          ; A03E B9 AB A0                 ...
        sta     $BC                             ; A041 85 BC                    ..
        ldy     #$1D                            ; A043 A0 1D                    ..
        lda     screen_hi_ptrs,y                ; A045 B9 00 1E                 ...
        sta     screen_ptr+1                    ; A048 85 C1                    ..
        lda     screen_lo_ptrs,y                ; A04A B9 00 1D                 ...
        sta     screen_ptr                      ; A04D 85 C0                    ..
        ldy     #$27                            ; A04F A0 27                    .'
        ldx     #$00                            ; A051 A2 00                    ..
LA053:  lda     $BC                             ; A053 A5 BC                    ..
        sta     (screen_ptr),y                  ; A055 91 C0                    ..
        inx                                     ; A057 E8                       .
        dey                                     ; A058 88                       .
        bpl     LA053                           ; A059 10 F8                    ..
        ldy     #$00                            ; A05B A0 00                    ..
        lda     screen_hi_ptrs,y                ; A05D B9 00 1E                 ...
        sta     screen_ptr+1                    ; A060 85 C1                    ..
        lda     screen_lo_ptrs,y                ; A062 B9 00 1D                 ...
        sta     screen_ptr                      ; A065 85 C0                    ..
        ldy     #$1E                            ; A067 A0 1E                    ..
        lda     $BC                             ; A069 A5 BC                    ..
        and     #$C0                            ; A06B 29 C0                    ).
        sta     (screen_ptr),y                  ; A06D 91 C0                    ..
        dey                                     ; A06F 88                       .
        ldx     #$00                            ; A070 A2 00                    ..
LA072:  lda     $BC                             ; A072 A5 BC                    ..
        sta     (screen_ptr),y                  ; A074 91 C0                    ..
        dey                                     ; A076 88                       .
        inx                                     ; A077 E8                       .
        cpx     #$14                            ; A078 E0 14                    ..
        bcc     LA072                           ; A07A 90 F6                    ..
        ldy     #$01                            ; A07C A0 01                    ..
        lda     screen_hi_ptrs,y                ; A07E B9 00 1E                 ...
        sta     screen_ptr+1                    ; A081 85 C1                    ..
        lda     screen_lo_ptrs,y                ; A083 B9 00 1D                 ...
        sta     screen_ptr                      ; A086 85 C0                    ..
        ldy     #$15                            ; A088 A0 15                    ..
        lda     #$FF                            ; A08A A9 FF                    ..
LA08C:  sta     (screen_ptr),y                  ; A08C 91 C0                    ..
        dey                                     ; A08E 88                       .
        cpy     #$12                            ; A08F C0 12                    ..
        bcs     LA08C                           ; A091 B0 F9                    ..
        ldy     #$1C                            ; A093 A0 1C                    ..
        lda     screen_hi_ptrs,y                ; A095 B9 00 1E                 ...
        sta     screen_ptr+1                    ; A098 85 C1                    ..
        lda     screen_lo_ptrs,y                ; A09A B9 00 1D                 ...
        sta     screen_ptr                      ; A09D 85 C0                    ..
        ldy     #$15                            ; A09F A0 15                    ..
        lda     #$FF                            ; A0A1 A9 FF                    ..
LA0A3:  sta     (screen_ptr),y                  ; A0A3 91 C0                    ..
        dey                                     ; A0A5 88                       .
        cpy     #$12                            ; A0A6 C0 12                    ..
        bcs     LA0A3                           ; A0A8 B0 F9                    ..
        rts                                     ; A0AA 60                       `

; ----------------------------------------------------------------------------
scanner_border_table:
        .byte   $AA,$55,$FF,$00                 ; A0AB AA 55 FF 00              .U..
; ----------------------------------------------------------------------------
; draw enemies/humanoids in scanner
draw_scanner_sprite:
        sec                                     ; A0AF 38                       8
        lda     $DD                             ; A0B0 A5 DD                    ..
        sbc     $8D                             ; A0B2 E5 8D                    ..
        sta     sprite_x                        ; A0B4 85 E3                    ..
        lda     $DE                             ; A0B6 A5 DE                    ..
        sbc     $8E                             ; A0B8 E5 8E                    ..
        sta     $E4                             ; A0BA 85 E4                    ..
        bcs     LA0CA                           ; A0BC B0 0C                    ..
        lda     sprite_x                        ; A0BE A5 E3                    ..
        adc     #$80                            ; A0C0 69 80                    i.
        sta     sprite_x                        ; A0C2 85 E3                    ..
        lda     $E4                             ; A0C4 A5 E4                    ..
        adc     #$02                            ; A0C6 69 02                    i.
        sta     $E4                             ; A0C8 85 E4                    ..
LA0CA:  lsr     $E4                             ; A0CA 46 E4                    F.
        ror     sprite_x                        ; A0CC 66 E3                    f.
        lsr     $E4                             ; A0CE 46 E4                    F.
        ror     sprite_x                        ; A0D0 66 E3                    f.
        lsr     $E4                             ; A0D2 46 E4                    F.
        ror     sprite_x                        ; A0D4 66 E3                    f.
        clc                                     ; A0D6 18                       .
        lda     sprite_x                        ; A0D7 A5 E3                    ..
        adc     #$28                            ; A0D9 69 28                    i(
        sta     sprite_x                        ; A0DB 85 E3                    ..
        lda     sprite_y                        ; A0DD A5 DF                    ..
        lsr     a                               ; A0DF 4A                       J
        lsr     a                               ; A0E0 4A                       J
        lsr     a                               ; A0E1 4A                       J
        tay                                     ; A0E2 A8                       .
        pha                                     ; A0E3 48                       H
        lda     screen_hi_ptrs,y                ; A0E4 B9 00 1E                 ...
        sta     screen_ptr+1                    ; A0E7 85 C1                    ..
        lda     screen_lo_ptrs,y                ; A0E9 B9 00 1D                 ...
        sta     screen_ptr                      ; A0EC 85 C0                    ..
        ldx     sprite_x                        ; A0EE A6 E3                    ..
        ldy     horiz_offset_table,x            ; A0F0 BC 00 1B                 ...
        lda     scanner_colormask               ; A0F3 A5 A9                    ..
        and     pixel_mask_table,x              ; A0F5 3D 00 1C                 =..
        ora     (screen_ptr),y                  ; A0F8 11 C0                    ..
        sta     (screen_ptr),y                  ; A0FA 91 C0                    ..
        ldy     horiz_offset_table+1,x          ; A0FC BC 01 1B                 ...
        lda     scanner_colormask               ; A0FF A5 A9                    ..
        and     pixel_mask_table+1,x            ; A101 3D 01 1C                 =..
        ora     (screen_ptr),y                  ; A104 11 C0                    ..
        sta     (screen_ptr),y                  ; A106 91 C0                    ..
        pla                                     ; A108 68                       h
        tay                                     ; A109 A8                       .
        lda     screen_hi_ptrs+1,y              ; A10A B9 01 1E                 ...
        sta     screen_ptr+1                    ; A10D 85 C1                    ..
        lda     screen_lo_ptrs+1,y              ; A10F B9 01 1D                 ...
        sta     screen_ptr                      ; A112 85 C0                    ..
        ldy     horiz_offset_table,x            ; A114 BC 00 1B                 ...
        lda     scanner_colormask               ; A117 A5 A9                    ..
        and     pixel_mask_table,x              ; A119 3D 00 1C                 =..
        ora     (screen_ptr),y                  ; A11C 11 C0                    ..
        sta     (screen_ptr),y                  ; A11E 91 C0                    ..
        ldy     horiz_offset_table+1,x          ; A120 BC 01 1B                 ...
        lda     scanner_colormask               ; A123 A5 A9                    ..
        and     pixel_mask_table+1,x            ; A125 3D 01 1C                 =..
        ora     (screen_ptr),y                  ; A128 11 C0                    ..
        sta     (screen_ptr),y                  ; A12A 91 C0                    ..
        rts                                     ; A12C 60                       `

; ----------------------------------------------------------------------------
; erase enemies/humanoids in scanner
erase_scanner_sprite:
        sec                                     ; A12D 38                       8
        lda     $DD                             ; A12E A5 DD                    ..
        sbc     $8F                             ; A130 E5 8F                    ..
        sta     sprite_x                        ; A132 85 E3                    ..
        lda     $DE                             ; A134 A5 DE                    ..
        sbc     $90                             ; A136 E5 90                    ..
        sta     $E4                             ; A138 85 E4                    ..
        bcs     LA148                           ; A13A B0 0C                    ..
        lda     sprite_x                        ; A13C A5 E3                    ..
        adc     #$80                            ; A13E 69 80                    i.
        sta     sprite_x                        ; A140 85 E3                    ..
        lda     $E4                             ; A142 A5 E4                    ..
        adc     #$02                            ; A144 69 02                    i.
        sta     $E4                             ; A146 85 E4                    ..
LA148:  lsr     $E4                             ; A148 46 E4                    F.
        ror     sprite_x                        ; A14A 66 E3                    f.
        lsr     $E4                             ; A14C 46 E4                    F.
        ror     sprite_x                        ; A14E 66 E3                    f.
        lsr     $E4                             ; A150 46 E4                    F.
        ror     sprite_x                        ; A152 66 E3                    f.
        clc                                     ; A154 18                       .
        lda     sprite_x                        ; A155 A5 E3                    ..
        adc     #$28                            ; A157 69 28                    i(
        sta     sprite_x                        ; A159 85 E3                    ..
        lda     sprite_y                        ; A15B A5 DF                    ..
        lsr     a                               ; A15D 4A                       J
        lsr     a                               ; A15E 4A                       J
        lsr     a                               ; A15F 4A                       J
        tay                                     ; A160 A8                       .
        pha                                     ; A161 48                       H
        lda     screen_hi_ptrs,y                ; A162 B9 00 1E                 ...
        sta     screen_ptr+1                    ; A165 85 C1                    ..
        lda     screen_lo_ptrs,y                ; A167 B9 00 1D                 ...
        sta     screen_ptr                      ; A16A 85 C0                    ..
        ldx     sprite_x                        ; A16C A6 E3                    ..
        ldy     horiz_offset_table,x            ; A16E BC 00 1B                 ...
        lda     #$00                            ; A171 A9 00                    ..
        sta     (screen_ptr),y                  ; A173 91 C0                    ..
        ldy     horiz_offset_table+1,x          ; A175 BC 01 1B                 ...
        sta     (screen_ptr),y                  ; A178 91 C0                    ..
        pla                                     ; A17A 68                       h
        tay                                     ; A17B A8                       .
        lda     screen_hi_ptrs+1,y              ; A17C B9 01 1E                 ...
        sta     screen_ptr+1                    ; A17F 85 C1                    ..
        lda     screen_lo_ptrs+1,y              ; A181 B9 01 1D                 ...
        sta     screen_ptr                      ; A184 85 C0                    ..
        ldy     horiz_offset_table,x            ; A186 BC 00 1B                 ...
        lda     #$00                            ; A189 A9 00                    ..
        sta     (screen_ptr),y                  ; A18B 91 C0                    ..
        ldy     horiz_offset_table+1,x          ; A18D BC 01 1B                 ...
        sta     (screen_ptr),y                  ; A190 91 C0                    ..
        rts                                     ; A192 60                       `

; ----------------------------------------------------------------------------
; draw the player's ship (white cross) in the scanner
draw_scanner_ship:
        lda     ship_y_pos                      ; A193 A5 C4                    ..
        lsr     a                               ; A195 4A                       J
        lsr     a                               ; A196 4A                       J
        lsr     a                               ; A197 4A                       J
        sec                                     ; A198 38                       8
        sbc     #$01                            ; A199 E9 01                    ..
        sta     sprite_x                        ; A19B 85 E3                    ..
        tay                                     ; A19D A8                       .
        lda     screen_hi_ptrs,y                ; A19E B9 00 1E                 ...
        sta     screen_ptr+1                    ; A1A1 85 C1                    ..
        lda     screen_lo_ptrs,y                ; A1A3 B9 00 1D                 ...
        sta     screen_ptr                      ; A1A6 85 C0                    ..
        lda     ship_x_pos                      ; A1A8 A5 C3                    ..
        lsr     a                               ; A1AA 4A                       J
        lsr     a                               ; A1AB 4A                       J
        lsr     a                               ; A1AC 4A                       J
        clc                                     ; A1AD 18                       .
        adc     #$46                            ; A1AE 69 46                    iF
        sta     $E4                             ; A1B0 85 E4                    ..
        tax                                     ; A1B2 AA                       .
        ldy     horiz_offset_table,x            ; A1B3 BC 00 1B                 ...
        lda     #$FF                            ; A1B6 A9 FF                    ..
        and     pixel_mask_table,x              ; A1B8 3D 00 1C                 =..
        ora     (screen_ptr),y                  ; A1BB 11 C0                    ..
        sta     (screen_ptr),y                  ; A1BD 91 C0                    ..
        ldy     sprite_x                        ; A1BF A4 E3                    ..
        lda     screen_hi_ptrs+1,y              ; A1C1 B9 01 1E                 ...
        sta     screen_ptr+1                    ; A1C4 85 C1                    ..
        lda     screen_lo_ptrs+1,y              ; A1C6 B9 01 1D                 ...
        sta     screen_ptr                      ; A1C9 85 C0                    ..
        ldx     $E4                             ; A1CB A6 E4                    ..
        ldy     $1AFF,x                         ; A1CD BC FF 1A                 ...
        lda     #$FF                            ; A1D0 A9 FF                    ..
        and     horiz_offset_table+255,x        ; A1D2 3D FF 1B                 =..
        ora     (screen_ptr),y                  ; A1D5 11 C0                    ..
        sta     (screen_ptr),y                  ; A1D7 91 C0                    ..
        ldy     horiz_offset_table,x            ; A1D9 BC 00 1B                 ...
        lda     #$FF                            ; A1DC A9 FF                    ..
        and     pixel_mask_table,x              ; A1DE 3D 00 1C                 =..
        ora     (screen_ptr),y                  ; A1E1 11 C0                    ..
        sta     (screen_ptr),y                  ; A1E3 91 C0                    ..
        ldy     horiz_offset_table+1,x          ; A1E5 BC 01 1B                 ...
        lda     #$FF                            ; A1E8 A9 FF                    ..
        and     pixel_mask_table+1,x            ; A1EA 3D 01 1C                 =..
        ora     (screen_ptr),y                  ; A1ED 11 C0                    ..
        sta     (screen_ptr),y                  ; A1EF 91 C0                    ..
        ldy     sprite_x                        ; A1F1 A4 E3                    ..
        lda     screen_hi_ptrs+2,y              ; A1F3 B9 02 1E                 ...
        sta     screen_ptr+1                    ; A1F6 85 C1                    ..
        lda     screen_lo_ptrs+2,y              ; A1F8 B9 02 1D                 ...
        sta     screen_ptr                      ; A1FB 85 C0                    ..
        ldx     $E4                             ; A1FD A6 E4                    ..
        ldy     horiz_offset_table,x            ; A1FF BC 00 1B                 ...
        lda     #$FF                            ; A202 A9 FF                    ..
        and     pixel_mask_table,x              ; A204 3D 00 1C                 =..
        ora     (screen_ptr),y                  ; A207 11 C0                    ..
        sta     (screen_ptr),y                  ; A209 91 C0                    ..
        rts                                     ; A20B 60                       `

; ----------------------------------------------------------------------------
; erase the player's ship (white cross) in the scanner
erase_scanner_ship:
        lda     ship_y_pos                      ; A20C A5 C4                    ..
        lsr     a                               ; A20E 4A                       J
        lsr     a                               ; A20F 4A                       J
        lsr     a                               ; A210 4A                       J
        sec                                     ; A211 38                       8
        sbc     #$01                            ; A212 E9 01                    ..
        sta     sprite_x                        ; A214 85 E3                    ..
        tay                                     ; A216 A8                       .
        lda     screen_hi_ptrs,y                ; A217 B9 00 1E                 ...
        sta     screen_ptr+1                    ; A21A 85 C1                    ..
        lda     screen_lo_ptrs,y                ; A21C B9 00 1D                 ...
        sta     screen_ptr                      ; A21F 85 C0                    ..
        lda     ship_x_pos                      ; A221 A5 C3                    ..
        lsr     a                               ; A223 4A                       J
        lsr     a                               ; A224 4A                       J
        lsr     a                               ; A225 4A                       J
        clc                                     ; A226 18                       .
        adc     #$46                            ; A227 69 46                    iF
        sta     $E4                             ; A229 85 E4                    ..
        tax                                     ; A22B AA                       .
        ldy     horiz_offset_table,x            ; A22C BC 00 1B                 ...
        lda     #$00                            ; A22F A9 00                    ..
        sta     (screen_ptr),y                  ; A231 91 C0                    ..
        ldy     sprite_x                        ; A233 A4 E3                    ..
        lda     screen_hi_ptrs+1,y              ; A235 B9 01 1E                 ...
        sta     screen_ptr+1                    ; A238 85 C1                    ..
        lda     screen_lo_ptrs+1,y              ; A23A B9 01 1D                 ...
        sta     screen_ptr                      ; A23D 85 C0                    ..
        ldx     $E4                             ; A23F A6 E4                    ..
        ldy     $1AFF,x                         ; A241 BC FF 1A                 ...
        lda     #$00                            ; A244 A9 00                    ..
        sta     (screen_ptr),y                  ; A246 91 C0                    ..
        ldy     horiz_offset_table,x            ; A248 BC 00 1B                 ...
        sta     (screen_ptr),y                  ; A24B 91 C0                    ..
        ldy     horiz_offset_table+1,x          ; A24D BC 01 1B                 ...
        sta     (screen_ptr),y                  ; A250 91 C0                    ..
        ldy     sprite_x                        ; A252 A4 E3                    ..
        lda     screen_hi_ptrs+2,y              ; A254 B9 02 1E                 ...
        sta     screen_ptr+1                    ; A257 85 C1                    ..
        lda     screen_lo_ptrs+2,y              ; A259 B9 02 1D                 ...
        sta     screen_ptr                      ; A25C 85 C0                    ..
        ldx     $E4                             ; A25E A6 E4                    ..
        ldy     horiz_offset_table,x            ; A260 BC 00 1B                 ...
        lda     #$00                            ; A263 A9 00                    ..
        sta     (screen_ptr),y                  ; A265 91 C0                    ..
        rts                                     ; A267 60                       `

; ----------------------------------------------------------------------------
init_work_ram:
        ldy     #$00                            ; A268 A0 00                    ..
LA26A:  lda     #$00                            ; A26A A9 00                    ..
        sta     sprite_list,y                   ; A26C 99 EB 0A                 ...
        sta     sprite_list+128,y               ; A26F 99 6B 0B                 .k.
        sta     enemy_explosion_table,y         ; A272 99 2B 05                 .+.
        sta     actor_list,y                    ; A275 99 6B 0C                 .k.
        iny                                     ; A278 C8                       .
        bpl     LA26A                           ; A279 10 EF                    ..
LA27B:  sta     actor_list,y                    ; A27B 99 6B 0C                 .k.
        iny                                     ; A27E C8                       .
        cpy     #$C0                            ; A27F C0 C0                    ..
        bcc     LA27B                           ; A281 90 F8                    ..
        ldx     #$00                            ; A283 A2 00                    ..
LA285:  lda     #$00                            ; A285 A9 00                    ..
        sta     player_shots_y,x                ; A287 9D 1A 05                 ...
        inx                                     ; A28A E8                       .
        cpx     #$10                            ; A28B E0 10                    ..
        bcc     LA285                           ; A28D 90 F6                    ..
        ldx     #$00                            ; A28F A2 00                    ..
; copy is done because the code is self-modifying
copy_code_to_ram:
        lda     draw_sprite_left,x              ; A291 BD 7B AA                 .{.
        sta     draw_sprite_left_copy,x         ; A294 9D 00 1F                 ...
        lda     draw_sprite_right,x             ; A297 BD D7 AA                 ...
        sta     draw_sprite_right_copy,x        ; A29A 9D 80 1F                 ...
        inx                                     ; A29D E8                       .
        bpl     copy_code_to_ram                ; A29E 10 F1                    ..
        lda     #$2F                            ; A2A0 A9 2F                    ./
        sta     tmp_ptr                         ; A2A2 85 E7                    ..
        lda     #$0D                            ; A2A4 A9 0D                    ..
        sta     tmp_ptr+1                       ; A2A6 85 E8                    ..
        ldy     #$00                            ; A2A8 A0 00                    ..
clr_ram_sprites_loop:
        lda     #$00                            ; A2AA A9 00                    ..
        sta     (tmp_ptr),y                     ; A2AC 91 E7                    ..
        inc     tmp_ptr                         ; A2AE E6 E7                    ..
        bne     crsl_ok                         ; A2B0 D0 02                    ..
        inc     tmp_ptr+1                       ; A2B2 E6 E8                    ..
crsl_ok:lda     tmp_ptr                         ; A2B4 A5 E7                    ..
        cmp     #$2F                            ; A2B6 C9 2F                    ./
        lda     tmp_ptr+1                       ; A2B8 A5 E8                    ..
        sbc     #$14                            ; A2BA E9 14                    ..
        bcc     clr_ram_sprites_loop            ; A2BC 90 EC                    ..
        ldx     #$00                            ; A2BE A2 00                    ..
copy_ram_sprites_loop:
        lda     sprom_humanoid,x                ; A2C0 BD B3 A8                 ...
        sta     sp_humanoid,x                   ; A2C3 9D 2F 0D                 ./.
        lda     sprom_lander_1,x                ; A2C6 BD C3 A8                 ...
        sta     sp_lander_1,x                   ; A2C9 9D 6F 0D                 .o.
        lda     sprom_lander_2,x                ; A2CC BD D3 A8                 ...
        sta     sp_lander_2,x                   ; A2CF 9D AF 0D                 ...
        lda     sprom_mutant_1,x                ; A2D2 BD E3 A8                 ...
        sta     sp_mutant_1,x                   ; A2D5 9D EF 0D                 ...
        lda     sprom_mutant_2,x                ; A2D8 BD F3 A8                 ...
        sta     sp_mutant_2,x                   ; A2DB 9D 2F 0E                 ./.
        lda     sprom_rship_l_1,x               ; A2DE BD 03 A9                 ...
        sta     sp_rship_l_1,x                  ; A2E1 9D 6F 0E                 .o.
        lda     sprom_rship_r_1,x               ; A2E4 BD 13 A9                 ...
        sta     sp_rship_r_1,x                  ; A2E7 9D AF 0E                 ...
        lda     sprom_rship_l_2,x               ; A2EA BD 23 A9                 .#.
        sta     sp_rship_l_2,x                  ; A2ED 9D EF 0E                 ...
        lda     sprom_rship_r_2,x               ; A2F0 BD 33 A9                 .3.
        sta     sp_rship_r_2,x                  ; A2F3 9D 2F 0F                 ./.
        lda     sprom_lship_l_1,x               ; A2F6 BD 43 A9                 .C.
        sta     sp_lship_l_1,x                  ; A2F9 9D 6F 0F                 .o.
        lda     sprom_lship_r_1,x               ; A2FC BD 53 A9                 .S.
        sta     sp_lship_r_1,x                  ; A2FF 9D AF 0F                 ...
        lda     sprom_lship_l_2,x               ; A302 BD 63 A9                 .c.
        sta     sp_lship_l_2,x                  ; A305 9D EF 0F                 ...
        lda     sprom_lship_r_2,x               ; A308 BD 73 A9                 .s.
        sta     sp_lship_r_2,x                  ; A30B 9D 2F 10                 ./.
        lda     sprom_bullet,x                  ; A30E BD 83 A9                 ...
        sta     sp_bullet,x                     ; A311 9D 6F 10                 .o.
        lda     sprom_bomber_1,x                ; A314 BD 93 A9                 ...
        sta     sp_bomber_1,x                   ; A317 9D AF 10                 ...
        lda     sprom_bomber_2,x                ; A31A BD A3 A9                 ...
        sta     sp_bomber_2,x                   ; A31D 9D EF 10                 ...
        lda     sprom_xbomb,x                   ; A320 BD B3 A9                 ...
        sta     sp_xbomb,x                      ; A323 9D 2F 11                 ./.
        lda     sprom_lflame_1,x                ; A326 BD E3 A9                 ...
        sta     sp_lflame_1,x                   ; A329 9D 6F 11                 .o.
        lda     sprom_lflame_2,x                ; A32C BD F3 A9                 ...
        sta     sp_lflame_2,x                   ; A32F 9D AF 11                 ...
        lda     sprom_rflame_1,x                ; A332 BD C3 A9                 ...
        sta     sp_rflame_1,x                   ; A335 9D EF 11                 ...
        lda     sprom_rflame_2,x                ; A338 BD D3 A9                 ...
        sta     sp_rflame_2,x                   ; A33B 9D 2F 12                 ./.
        lda     sprom_pod_1,x                   ; A33E BD 03 AA                 ...
        sta     sp_pod_1,x                      ; A341 9D 6F 12                 .o.
        lda     sprom_pod_2,x                   ; A344 BD 13 AA                 ...
        sta     sp_pod_2,x                      ; A347 9D AF 12                 ...
        lda     sprom_swarmer,x                 ; A34A BD 23 AA                 .#.
        sta     sp_swarmer,x                    ; A34D 9D EF 12                 ...
        lda     sprom_baiter_l,x                ; A350 BD 33 AA                 .3.
        sta     sp_baiter_l,x                   ; A353 9D 2F 13                 ./.
        lda     sprom_baiter_r,x                ; A356 BD 43 AA                 .C.
        sta     sp_baiter_r,x                   ; A359 9D 6F 13                 .o.
        lda     sprom_smartbomb_1,x             ; A35C BD 53 AA                 .S.
        sta     sp_smartbomb_1,x                ; A35F 9D AF 13                 ...
        lda     sprom_smartbomb_2,x             ; A362 BD 63 AA                 .c.
        sta     sp_smartbomb_2,x                ; A365 9D EF 13                 ...
        inx                                     ; A368 E8                       .
        cpx     #$10                            ; A369 E0 10                    ..
        bcs     preshift_all_sprites            ; A36B B0 03                    ..
        jmp     copy_ram_sprites_loop           ; A36D 4C C0 A2                 L..

; ----------------------------------------------------------------------------
; this is why sprites are copied to RAM: we precalculate right-shifted copies, to speed up drawing
preshift_all_sprites:
        lda     #$2F                            ; A370 A9 2F                    ./
        sta     preshift_ptr                    ; A372 85 80                    ..
        lda     #$0D                            ; A374 A9 0D                    ..
        sta     preshift_ptr+1                  ; A376 85 81                    ..
        jsr     preshift_sprite                 ; A378 20 9F AB                  ..
        lda     #$AF                            ; A37B A9 AF                    ..
        sta     preshift_ptr                    ; A37D 85 80                    ..
        lda     #$13                            ; A37F A9 13                    ..
        sta     preshift_ptr+1                  ; A381 85 81                    ..
        jsr     preshift_sprite                 ; A383 20 9F AB                  ..
        lda     #$EF                            ; A386 A9 EF                    ..
        sta     preshift_ptr                    ; A388 85 80                    ..
        lda     #$13                            ; A38A A9 13                    ..
        sta     preshift_ptr+1                  ; A38C 85 81                    ..
        jsr     preshift_sprite                 ; A38E 20 9F AB                  ..
        lda     #$6F                            ; A391 A9 6F                    .o
        sta     preshift_ptr                    ; A393 85 80                    ..
        lda     #$10                            ; A395 A9 10                    ..
        sta     preshift_ptr+1                  ; A397 85 81                    ..
        jsr     preshift_sprite                 ; A399 20 9F AB                  ..
        lda     #$6F                            ; A39C A9 6F                    .o
        sta     preshift_ptr                    ; A39E 85 80                    ..
        lda     #$0D                            ; A3A0 A9 0D                    ..
        sta     preshift_ptr+1                  ; A3A2 85 81                    ..
        jsr     preshift_sprite                 ; A3A4 20 9F AB                  ..
        lda     #$2F                            ; A3A7 A9 2F                    ./
        sta     preshift_ptr                    ; A3A9 85 80                    ..
        lda     #$13                            ; A3AB A9 13                    ..
        sta     preshift_ptr+1                  ; A3AD 85 81                    ..
        jsr     preshift_sprite                 ; A3AF 20 9F AB                  ..
        lda     #$6F                            ; A3B2 A9 6F                    .o
        sta     preshift_ptr                    ; A3B4 85 80                    ..
        lda     #$13                            ; A3B6 A9 13                    ..
        sta     preshift_ptr+1                  ; A3B8 85 81                    ..
        jsr     preshift_sprite                 ; A3BA 20 9F AB                  ..
        lda     #$AF                            ; A3BD A9 AF                    ..
        sta     preshift_ptr                    ; A3BF 85 80                    ..
        lda     #$0D                            ; A3C1 A9 0D                    ..
        sta     preshift_ptr+1                  ; A3C3 85 81                    ..
        jsr     preshift_sprite                 ; A3C5 20 9F AB                  ..
        lda     #$EF                            ; A3C8 A9 EF                    ..
        sta     preshift_ptr                    ; A3CA 85 80                    ..
        lda     #$0D                            ; A3CC A9 0D                    ..
        sta     preshift_ptr+1                  ; A3CE 85 81                    ..
        jsr     preshift_sprite                 ; A3D0 20 9F AB                  ..
        lda     #$2F                            ; A3D3 A9 2F                    ./
        sta     preshift_ptr                    ; A3D5 85 80                    ..
        lda     #$0E                            ; A3D7 A9 0E                    ..
        sta     preshift_ptr+1                  ; A3D9 85 81                    ..
        jsr     preshift_sprite                 ; A3DB 20 9F AB                  ..
        lda     #$6F                            ; A3DE A9 6F                    .o
        sta     preshift_ptr                    ; A3E0 85 80                    ..
        lda     #$0E                            ; A3E2 A9 0E                    ..
        sta     preshift_ptr+1                  ; A3E4 85 81                    ..
        jsr     preshift_sprite                 ; A3E6 20 9F AB                  ..
        lda     #$AF                            ; A3E9 A9 AF                    ..
        sta     preshift_ptr                    ; A3EB 85 80                    ..
        lda     #$0E                            ; A3ED A9 0E                    ..
        sta     preshift_ptr+1                  ; A3EF 85 81                    ..
        jsr     preshift_sprite                 ; A3F1 20 9F AB                  ..
        lda     #$EF                            ; A3F4 A9 EF                    ..
        sta     preshift_ptr                    ; A3F6 85 80                    ..
        lda     #$0E                            ; A3F8 A9 0E                    ..
        sta     preshift_ptr+1                  ; A3FA 85 81                    ..
        jsr     preshift_sprite                 ; A3FC 20 9F AB                  ..
        lda     #$2F                            ; A3FF A9 2F                    ./
        sta     preshift_ptr                    ; A401 85 80                    ..
        lda     #$0F                            ; A403 A9 0F                    ..
        sta     preshift_ptr+1                  ; A405 85 81                    ..
        jsr     preshift_sprite                 ; A407 20 9F AB                  ..
        lda     #$6F                            ; A40A A9 6F                    .o
        sta     preshift_ptr                    ; A40C 85 80                    ..
        lda     #$0F                            ; A40E A9 0F                    ..
        sta     preshift_ptr+1                  ; A410 85 81                    ..
        jsr     preshift_sprite                 ; A412 20 9F AB                  ..
        lda     #$AF                            ; A415 A9 AF                    ..
        sta     preshift_ptr                    ; A417 85 80                    ..
        lda     #$0F                            ; A419 A9 0F                    ..
        sta     preshift_ptr+1                  ; A41B 85 81                    ..
        jsr     preshift_sprite                 ; A41D 20 9F AB                  ..
        lda     #$EF                            ; A420 A9 EF                    ..
        sta     preshift_ptr                    ; A422 85 80                    ..
        lda     #$0F                            ; A424 A9 0F                    ..
        sta     preshift_ptr+1                  ; A426 85 81                    ..
        jsr     preshift_sprite                 ; A428 20 9F AB                  ..
        lda     #$2F                            ; A42B A9 2F                    ./
        sta     preshift_ptr                    ; A42D 85 80                    ..
        lda     #$10                            ; A42F A9 10                    ..
        sta     preshift_ptr+1                  ; A431 85 81                    ..
        jsr     preshift_sprite                 ; A433 20 9F AB                  ..
        lda     #$AF                            ; A436 A9 AF                    ..
        sta     preshift_ptr                    ; A438 85 80                    ..
        lda     #$10                            ; A43A A9 10                    ..
        sta     preshift_ptr+1                  ; A43C 85 81                    ..
        jsr     preshift_sprite                 ; A43E 20 9F AB                  ..
        lda     #$EF                            ; A441 A9 EF                    ..
        sta     preshift_ptr                    ; A443 85 80                    ..
        lda     #$10                            ; A445 A9 10                    ..
        sta     preshift_ptr+1                  ; A447 85 81                    ..
        jsr     preshift_sprite                 ; A449 20 9F AB                  ..
        lda     #$2F                            ; A44C A9 2F                    ./
        sta     preshift_ptr                    ; A44E 85 80                    ..
        lda     #$11                            ; A450 A9 11                    ..
        sta     preshift_ptr+1                  ; A452 85 81                    ..
        jsr     preshift_sprite                 ; A454 20 9F AB                  ..
        lda     #$6F                            ; A457 A9 6F                    .o
        sta     preshift_ptr                    ; A459 85 80                    ..
        lda     #$11                            ; A45B A9 11                    ..
        sta     preshift_ptr+1                  ; A45D 85 81                    ..
        jsr     preshift_sprite                 ; A45F 20 9F AB                  ..
        lda     #$AF                            ; A462 A9 AF                    ..
        sta     preshift_ptr                    ; A464 85 80                    ..
        lda     #$11                            ; A466 A9 11                    ..
        sta     preshift_ptr+1                  ; A468 85 81                    ..
        jsr     preshift_sprite                 ; A46A 20 9F AB                  ..
        lda     #$EF                            ; A46D A9 EF                    ..
        sta     preshift_ptr                    ; A46F 85 80                    ..
        lda     #$11                            ; A471 A9 11                    ..
        sta     preshift_ptr+1                  ; A473 85 81                    ..
        jsr     preshift_sprite                 ; A475 20 9F AB                  ..
        lda     #$2F                            ; A478 A9 2F                    ./
        sta     preshift_ptr                    ; A47A 85 80                    ..
        lda     #$12                            ; A47C A9 12                    ..
        sta     preshift_ptr+1                  ; A47E 85 81                    ..
        jsr     preshift_sprite                 ; A480 20 9F AB                  ..
        lda     #$6F                            ; A483 A9 6F                    .o
        sta     preshift_ptr                    ; A485 85 80                    ..
        lda     #$12                            ; A487 A9 12                    ..
        sta     preshift_ptr+1                  ; A489 85 81                    ..
        jsr     preshift_sprite                 ; A48B 20 9F AB                  ..
        lda     #$AF                            ; A48E A9 AF                    ..
        sta     preshift_ptr                    ; A490 85 80                    ..
        lda     #$12                            ; A492 A9 12                    ..
        sta     preshift_ptr+1                  ; A494 85 81                    ..
        jsr     preshift_sprite                 ; A496 20 9F AB                  ..
        lda     #$EF                            ; A499 A9 EF                    ..
        sta     preshift_ptr                    ; A49B 85 80                    ..
        lda     #$12                            ; A49D A9 12                    ..
        sta     preshift_ptr+1                  ; A49F 85 81                    ..
        jsr     preshift_sprite                 ; A4A1 20 9F AB                  ..
        rts                                     ; A4A4 60                       `

; ----------------------------------------------------------------------------
; search for an empty slot. if found, add current_sprite to list, return with carry clear. if no empty slot, return with carry set.
add_to_sprite_list:
        ldy     #$00                            ; A4A5 A0 00                    ..
asl_next:
        lda     sprite_list,y                   ; A4A7 B9 EB 0A                 ...
        beq     asl_slot_found                  ; A4AA F0 0A                    ..
        tya                                     ; A4AC 98                       .
        clc                                     ; A4AD 18                       .
        adc     #$04                            ; A4AE 69 04                    i.
        tay                                     ; A4B0 A8                       .
        cpy     #$80                            ; A4B1 C0 80                    ..
        bcc     asl_next                        ; A4B3 90 F2                    ..
        rts                                     ; A4B5 60                       `

; ----------------------------------------------------------------------------
asl_slot_found:
        lda     sprite_y                        ; A4B6 A5 DF                    ..
        sta     sprite_list,y                   ; A4B8 99 EB 0A                 ...
        lda     $DD                             ; A4BB A5 DD                    ..
        sta     sprite_list+1,y                 ; A4BD 99 EC 0A                 ...
        lda     $DE                             ; A4C0 A5 DE                    ..
        sta     sprite_list+2,y                 ; A4C2 99 ED 0A                 ...
        lda     current_sprite                  ; A4C5 A5 F9                    ..
        sta     sprite_list+3,y                 ; A4C7 99 EE 0A                 ...
        clc                                     ; A4CA 18                       .
        rts                                     ; A4CB 60                       `

; ----------------------------------------------------------------------------
LA4CC:  lda     #$7C                            ; A4CC A9 7C                    .|
        sta     $98                             ; A4CE 85 98                    ..
        lda     #$00                            ; A4D0 A9 00                    ..
        sta     enemy_count                     ; A4D2 85 9C                    ..
        sta     humanoid_count                  ; A4D4 85 A1                    ..
        sta     $A2                             ; A4D6 85 A2                    ..
        inc     animation_counter               ; A4D8 E6 85                    ..
        jmp     LA520                           ; A4DA 4C 20 A5                 L .

; ----------------------------------------------------------------------------
LA4DD:  lda     $98                             ; A4DD A5 98                    ..
        sec                                     ; A4DF 38                       8
        sbc     #$04                            ; A4E0 E9 04                    ..
        sta     $98                             ; A4E2 85 98                    ..
        bpl     LA520                           ; A4E4 10 3A                    .:
        bit     ship_dead_flag                  ; A4E6 24 EF                    $.
        bpl     LA4ED                           ; A4E8 10 03                    ..
        jmp     start_player_death              ; A4EA 4C 4C B6                 LL.

; ----------------------------------------------------------------------------
LA4ED:  lda     game_type                       ; A4ED A5 E1                    ..
        beq     LA4F6                           ; A4EF F0 05                    ..
        bit     invuln_flag                     ; A4F1 24 ED                    $.
        bpl     LA4F6                           ; A4F3 10 01                    ..
        rts                                     ; A4F5 60                       `

; ----------------------------------------------------------------------------
LA4F6:  lda     enemy_count                     ; A4F6 A5 9C                    ..
        ora     landers_to_spawn                ; A4F8 05 9B                    ..
        ora     baiter_count                    ; A4FA 05 9D                    ..
        bne     LA509                           ; A4FC D0 0B                    ..
        jsr     clear_baiters                   ; A4FE 20 6D B8                  m.
        jsr     clear_temp_enemies              ; A501 20 69 B7                  i.
        pla                                     ; A504 68                       h
        pla                                     ; A505 68                       h
        jmp     next_level                      ; A506 4C C9 83                 L..

; ----------------------------------------------------------------------------
LA509:  lda     planet_dead_flag                ; A509 A5 A0                    ..
        bmi     LA51F                           ; A50B 30 12                    0.
        lda     humanoid_count                  ; A50D A5 A1                    ..
        bne     LA51F                           ; A50F D0 0E                    ..
        jsr     clear_temp_enemies              ; A511 20 69 B7                  i.
        jsr     destroy_planet                  ; A514 20 0A 9E                  ..
        sec                                     ; A517 38                       8
        ror     planet_dead_flag                ; A518 66 A0                    f.
        pla                                     ; A51A 68                       h
        pla                                     ; A51B 68                       h
        jmp     prep_next_level                 ; A51C 4C 65 84                 Le.

; ----------------------------------------------------------------------------
LA51F:  rts                                     ; A51F 60                       `

; ----------------------------------------------------------------------------
LA520:  ldy     $98                             ; A520 A4 98                    ..
        lda     sprite_list,y                   ; A522 B9 EB 0A                 ...
        beq     LA4DD                           ; A525 F0 B6                    ..
        sta     sprite_y                        ; A527 85 DF                    ..
        lda     sprite_list+1,y                 ; A529 B9 EC 0A                 ...
        sta     $DD                             ; A52C 85 DD                    ..
        lda     sprite_list+2,y                 ; A52E B9 ED 0A                 ...
        sta     $DE                             ; A531 85 DE                    ..
        lda     sprite_list+3,y                 ; A533 B9 EE 0A                 ...
        sta     current_sprite                  ; A536 85 F9                    ..
        and     #$07                            ; A538 29 07                    ).
        cmp     #$03                            ; A53A C9 03                    ..
        beq     LA556                           ; A53C F0 18                    ..
        lda     animation_counter               ; A53E A5 85                    ..
        and     #$03                            ; A540 29 03                    ).
        asl     a                               ; A542 0A                       .
        asl     a                               ; A543 0A                       .
        asl     a                               ; A544 0A                       .
        sta     sprite_x                        ; A545 85 E3                    ..
        lda     current_sprite                  ; A547 A5 F9                    ..
        and     #$07                            ; A549 29 07                    ).
        adc     sprite_x                        ; A54B 65 E3                    e.
        tay                                     ; A54D A8                       .
        lda     scanner_colormask_table,y       ; A54E B9 92 A5                 ...
        sta     scanner_colormask               ; A551 85 A9                    ..
        jsr     erase_scanner_sprite            ; A553 20 2D A1                  -.
LA556:  jsr     erase_sprite_XXX                ; A556 20 86 A7                  ..
        bcs     LA56D                           ; A559 B0 12                    ..
        lda     current_sprite                  ; A55B A5 F9                    ..
        cmp     #$07                            ; A55D C9 07                    ..
        bne     LA56D                           ; A55F D0 0C                    ..
; no other enemy is a double-wide sprite, is it?
erase_baiter_right_half:
        lda     sprite_x                        ; A561 A5 E3                    ..
        clc                                     ; A563 18                       .
        adc     #$05                            ; A564 69 05                    i.
        sta     sprite_x                        ; A566 85 E3                    ..
        bcs     LA56D                           ; A568 B0 03                    ..
        jsr     erase_sprite                    ; A56A 20 2C AB                  ,.
LA56D:  lda     current_sprite                  ; A56D A5 F9                    ..
        and     #$07                            ; A56F 29 07                    ).
        asl     a                               ; A571 0A                       .
        tay                                     ; A572 A8                       .
        lda     jump_table,y                    ; A573 B9 82 A5                 ...
        sta     trampoline                      ; A576 85 A7                    ..
        lda     jump_table+1,y                  ; A578 B9 83 A5                 ...
        sta     trampoline+1                    ; A57B 85 A8                    ..
        ldy     $98                             ; A57D A4 98                    ..
        jmp     (trampoline)                    ; A57F 6C A7 00                 l..

; ----------------------------------------------------------------------------
jump_table:
        .addr   spawn_humanoid                  ; A582 E6 AE                    ..
        .addr   spawn_lander                    ; A584 8E B0                    ..
        .addr   spawn_mutant                    ; A586 F4 B2                    ..
        .addr   spawn_enemy_shot                ; A588 86 9B                    ..
        .addr   spawn_bomber                    ; A58A F1 B3                    ..
        .addr   spawn_pod                       ; A58C 85 B4                    ..
        .addr   spawn_swarmer                   ; A58E A5 B4                    ..
        .addr   spawn_baiter                    ; A590 D4 BA                    ..
; ----------------------------------------------------------------------------
scanner_colormask_table:
        .byte   $FF,$55,$AA,$00,$FF,$AA,$AA,$55 ; A592 FF 55 AA 00 FF AA AA 55  .U.....U
        .byte   $FF,$55,$55,$00,$AA,$FF,$AA,$FF ; A59A FF 55 55 00 AA FF AA FF  .UU.....
        .byte   $FF,$55,$AA,$00,$FF,$55,$AA,$55 ; A5A2 FF 55 AA 00 FF 55 AA 55  .U...U.U
        .byte   $FF,$55,$55,$00,$AA,$FF,$AA,$FF ; A5AA FF 55 55 00 AA FF AA FF  .UU.....
; ----------------------------------------------------------------------------
LA5B2:  sec                                     ; A5B2 38                       8
        lda     $DD                             ; A5B3 A5 DD                    ..
        sbc     $89                             ; A5B5 E5 89                    ..
        sta     sprite_x                        ; A5B7 85 E3                    ..
        lda     $DE                             ; A5B9 A5 DE                    ..
        sbc     $8A                             ; A5BB E5 8A                    ..
        sta     $E4                             ; A5BD 85 E4                    ..
        bcs     LA5CD                           ; A5BF B0 0C                    ..
        lda     sprite_x                        ; A5C1 A5 E3                    ..
        adc     #$80                            ; A5C3 69 80                    i.
        sta     sprite_x                        ; A5C5 85 E3                    ..
        lda     $E4                             ; A5C7 A5 E4                    ..
        adc     #$02                            ; A5C9 69 02                    i.
        sta     $E4                             ; A5CB 85 E4                    ..
LA5CD:  lda     $DE                             ; A5CD A5 DE                    ..
        bmi     LA5EB                           ; A5CF 30 1A                    0.
        lda     $DD                             ; A5D1 A5 DD                    ..
        cmp     #$80                            ; A5D3 C9 80                    ..
        lda     $DE                             ; A5D5 A5 DE                    ..
        sbc     #$02                            ; A5D7 E9 02                    ..
        bcc     LA5F8                           ; A5D9 90 1D                    ..
        sec                                     ; A5DB 38                       8
        lda     $DD                             ; A5DC A5 DD                    ..
        sbc     #$80                            ; A5DE E9 80                    ..
        sta     $DD                             ; A5E0 85 DD                    ..
        lda     $DE                             ; A5E2 A5 DE                    ..
        sbc     #$02                            ; A5E4 E9 02                    ..
        sta     $DE                             ; A5E6 85 DE                    ..
        jmp     LA5F8                           ; A5E8 4C F8 A5                 L..

; ----------------------------------------------------------------------------
LA5EB:  clc                                     ; A5EB 18                       .
        lda     $DD                             ; A5EC A5 DD                    ..
        adc     #$80                            ; A5EE 69 80                    i.
        sta     $DD                             ; A5F0 85 DD                    ..
        lda     $DE                             ; A5F2 A5 DE                    ..
        adc     #$02                            ; A5F4 69 02                    i.
        sta     $DE                             ; A5F6 85 DE                    ..
LA5F8:  ldy     $98                             ; A5F8 A4 98                    ..
        lda     sprite_y                        ; A5FA A5 DF                    ..
        sta     sprite_list,y                   ; A5FC 99 EB 0A                 ...
        lda     $DD                             ; A5FF A5 DD                    ..
        sta     sprite_list+1,y                 ; A601 99 EC 0A                 ...
        lda     $DE                             ; A604 A5 DE                    ..
        sta     sprite_list+2,y                 ; A606 99 ED 0A                 ...
        lda     current_sprite                  ; A609 A5 F9                    ..
        sta     sprite_list+3,y                 ; A60B 99 EE 0A                 ...
        lda     current_sprite                  ; A60E A5 F9                    ..
        and     #$07                            ; A610 29 07                    ).
        cmp     #$03                            ; A612 C9 03                    ..
        beq     LA629                           ; A614 F0 13                    ..
        ldx     #$00                            ; A616 A2 00                    ..
LA618:  lda     player_shots_y,x                ; A618 BD 1A 05                 ...
        bne     LA645                           ; A61B D0 28                    .(
LA61D:  txa                                     ; A61D 8A                       .
        clc                                     ; A61E 18                       .
        adc     #$04                            ; A61F 69 04                    i.
        tax                                     ; A621 AA                       .
        cpx     #$10                            ; A622 E0 10                    ..
        bcc     LA618                           ; A624 90 F2                    ..
        jsr     draw_scanner_sprite             ; A626 20 AF A0                  ..
LA629:  jsr     draw_sprite                     ; A629 20 49 A7                  I.
        bcs     LA642                           ; A62C B0 14                    ..
        lda     current_sprite                  ; A62E A5 F9                    ..
        cmp     #$07                            ; A630 C9 07                    ..
        bne     LA642                           ; A632 D0 0E                    ..
        lda     sprite_x                        ; A634 A5 E3                    ..
        clc                                     ; A636 18                       .
        adc     #$05                            ; A637 69 05                    i.
        sta     sprite_x                        ; A639 85 E3                    ..
        bcs     LA642                           ; A63B B0 05                    ..
        lda     #$19                            ; A63D A9 19                    ..
        jsr     draw_sprite_right_copy          ; A63F 20 80 1F                  ..
LA642:  jmp     LA4DD                           ; A642 4C DD A4                 L..

; ----------------------------------------------------------------------------
LA645:  lda     sprite_y                        ; A645 A5 DF                    ..
        cmp     player_shots_y,x                ; A647 DD 1A 05                 ...
        bcs     LA61D                           ; A64A B0 D1                    ..
        adc     #$08                            ; A64C 69 08                    i.
        cmp     player_shots_y,x                ; A64E DD 1A 05                 ...
        bcc     LA61D                           ; A651 90 CA                    ..
        lda     $E4                             ; A653 A5 E4                    ..
        bne     LA61D                           ; A655 D0 C6                    ..
        lda     sprite_x                        ; A657 A5 E3                    ..
        cmp     #$A0                            ; A659 C9 A0                    ..
        bcs     LA61D                           ; A65B B0 C0                    ..
        lda     player_shots_delta,x            ; A65D BD 1D 05                 ...
        bpl     LA676                           ; A660 10 14                    ..
        lda     sprite_x                        ; A662 A5 E3                    ..
        cmp     player_shots_x_start,x          ; A664 DD 1B 05                 ...
        bcs     LA673                           ; A667 B0 0A                    ..
        lda     player_shots_x_end,x            ; A669 BD 1C 05                 ...
        clc                                     ; A66C 18                       .
        adc     #$01                            ; A66D 69 01                    i.
        cmp     sprite_x                        ; A66F C5 E3                    ..
        bcc     LA687                           ; A671 90 14                    ..
LA673:  jmp     LA61D                           ; A673 4C 1D A6                 L..

; ----------------------------------------------------------------------------
LA676:  lda     sprite_x                        ; A676 A5 E3                    ..
        cmp     player_shots_x_start,x          ; A678 DD 1B 05                 ...
        bcc     LA673                           ; A67B 90 F6                    ..
        lda     player_shots_x_end,x            ; A67D BD 1C 05                 ...
        sec                                     ; A680 38                       8
        sbc     #$01                            ; A681 E9 01                    ..
        cmp     sprite_x                        ; A683 C5 E3                    ..
        bcc     LA673                           ; A685 90 EC                    ..
LA687:  lda     #$00                            ; A687 A9 00                    ..
        sta     player_shots_x_end,x            ; A689 9D 1C 05                 ...
        lda     current_sprite                  ; A68C A5 F9                    ..
        cmp     #$05                            ; A68E C9 05                    ..
        bne     LA698                           ; A690 D0 06                    ..
        jsr     spawn_swarmers                  ; A692 20 11 A7                  ..
        jmp     LA6BB                           ; A695 4C BB A6                 L..

; ----------------------------------------------------------------------------
LA698:  cmp     #$11                            ; A698 C9 11                    ..
        bne     LA6BB                           ; A69A D0 1F                    ..
        ldy     $98                             ; A69C A4 98                    ..
        lda     sprite_list+128,y               ; A69E B9 6B 0B                 .k.
        tay                                     ; A6A1 A8                       .
        lda     sprite_list,y                   ; A6A2 B9 EB 0A                 ...
        beq     LA6BB                           ; A6A5 F0 14                    ..
        lda     sprite_list+3,y                 ; A6A7 B9 EE 0A                 ...
        cmp     #$08                            ; A6AA C9 08                    ..
        bne     LA6BB                           ; A6AC D0 0D                    ..
        lda     #$10                            ; A6AE A9 10                    ..
        sta     sprite_list+3,y                 ; A6B0 99 EE 0A                 ...
        lda     #$00                            ; A6B3 A9 00                    ..
        sta     sprite_list+128,y               ; A6B5 99 6B 0B                 .k.
        jsr     play_fall                       ; A6B8 20 08 8E                  ..
LA6BB:  lda     sprite_x                        ; A6BB A5 E3                    ..
        sta     $C9                             ; A6BD 85 C9                    ..
        lda     sprite_y                        ; A6BF A5 DF                    ..
        clc                                     ; A6C1 18                       .
        adc     #$04                            ; A6C2 69 04                    i.
        sta     $CA                             ; A6C4 85 CA                    ..
        lda     #$01                            ; A6C6 A9 01                    ..
        sta     $CB                             ; A6C8 85 CB                    ..
        ldy     $98                             ; A6CA A4 98                    ..
        lda     #$00                            ; A6CC A9 00                    ..
        sta     sprite_list,y                   ; A6CE 99 EB 0A                 ...
        lda     current_sprite                  ; A6D1 A5 F9                    ..
        and     #$07                            ; A6D3 29 07                    ).
        beq     LA6FF                           ; A6D5 F0 28                    .(
        cmp     #$05                            ; A6D7 C9 05                    ..
        beq     LA6F3                           ; A6D9 F0 18                    ..
        cmp     #$07                            ; A6DB C9 07                    ..
        beq     LA6ED                           ; A6DD F0 0E                    ..
        cmp     #$06                            ; A6DF C9 06                    ..
        beq     LA6F9                           ; A6E1 F0 16                    ..
        cmp     #$04                            ; A6E3 C9 04                    ..
        bne     LA705                           ; A6E5 D0 1E                    ..
        jsr     play_lander_died                ; A6E7 20 B4 8D                  ..
        jmp     LA708                           ; A6EA 4C 08 A7                 L..

; ----------------------------------------------------------------------------
LA6ED:  jsr     play_baiter_died                ; A6ED 20 C2 8D                  ..
        jmp     LA708                           ; A6F0 4C 08 A7                 L..

; ----------------------------------------------------------------------------
LA6F3:  jsr     play_pod_died                   ; A6F3 20 D0 8D                  ..
        jmp     LA708                           ; A6F6 4C 08 A7                 L..

; ----------------------------------------------------------------------------
LA6F9:  jsr     play_swarmer_died               ; A6F9 20 A6 8D                  ..
        jmp     LA708                           ; A6FC 4C 08 A7                 L..

; ----------------------------------------------------------------------------
LA6FF:  jsr     play_human_died                 ; A6FF 20 24 8E                  $.
        jmp     LA708                           ; A702 4C 08 A7                 L..

; ----------------------------------------------------------------------------
LA705:  jsr     play_lander_died                ; A705 20 B4 8D                  ..
LA708:  jsr     start_enemy_explosion           ; A708 20 E7 9B                  ..
        jsr     add_cursprite_points            ; A70B 20 AE A7                  ..
        jmp     LA4DD                           ; A70E 4C DD A4                 L..

; ----------------------------------------------------------------------------
; called when a pod dies
spawn_swarmers:
        lda     sprite_y                        ; A711 A5 DF                    ..
        pha                                     ; A713 48                       H
        sec                                     ; A714 38                       8
        sbc     #$12                            ; A715 E9 12                    ..
        sta     sprite_y                        ; A717 85 DF                    ..
        cmp     #$20                            ; A719 C9 20                    . 
        bcs     LA721                           ; A71B B0 04                    ..
        lda     #$20                            ; A71D A9 20                    . 
        sta     sprite_y                        ; A71F 85 DF                    ..
LA721:  lda     #$06                            ; A721 A9 06                    ..
        sta     current_sprite                  ; A723 85 F9                    ..
LA725:  pha                                     ; A725 48                       H
        jsr     add_to_sprite_list              ; A726 20 A5 A4                  ..
        bcs     LA734                           ; A729 B0 09                    ..
        jsr     get_random                      ; A72B 20 F2 8C                  ..
        sta     sprite_list+128,y               ; A72E 99 6B 0B                 .k.
        sta     sprite_list+129,y               ; A731 99 6C 0B                 .l.
LA734:  clc                                     ; A734 18                       .
        lda     sprite_y                        ; A735 A5 DF                    ..
        adc     #$06                            ; A737 69 06                    i.
        sta     sprite_y                        ; A739 85 DF                    ..
        pla                                     ; A73B 68                       h
        sec                                     ; A73C 38                       8
        sbc     #$01                            ; A73D E9 01                    ..
        bne     LA725                           ; A73F D0 E4                    ..
        pla                                     ; A741 68                       h
        sta     sprite_y                        ; A742 85 DF                    ..
        lda     #$05                            ; A744 A9 05                    ..
        sta     current_sprite                  ; A746 85 F9                    ..
        rts                                     ; A748 60                       `

; ----------------------------------------------------------------------------
; draw enemies/humanoids in playfield. return with carry set if there's a ship collision (player died), else clear.
draw_sprite:
        sec                                     ; A749 38                       8
        lda     $DD                             ; A74A A5 DD                    ..
        sbc     $89                             ; A74C E5 89                    ..
        sta     sprite_x                        ; A74E 85 E3                    ..
        lda     $DE                             ; A750 A5 DE                    ..
        sbc     $8A                             ; A752 E5 8A                    ..
        sta     $E4                             ; A754 85 E4                    ..
        bcs     LA764                           ; A756 B0 0C                    ..
        lda     sprite_x                        ; A758 A5 E3                    ..
        adc     #$80                            ; A75A 69 80                    i.
        sta     sprite_x                        ; A75C 85 E3                    ..
        lda     $E4                             ; A75E A5 E4                    ..
        adc     #$02                            ; A760 69 02                    i.
        sta     $E4                             ; A762 85 E4                    ..
LA764:  lda     $E4                             ; A764 A5 E4                    ..
        bne     LA784                           ; A766 D0 1C                    ..
        lda     sprite_x                        ; A768 A5 E3                    ..
        cmp     #$A0                            ; A76A C9 A0                    ..
        bcs     LA784                           ; A76C B0 16                    ..
        lda     current_sprite                  ; A76E A5 F9                    ..
        and     #$07                            ; A770 29 07                    ).
        beq     LA77F                           ; A772 F0 0B                    ..
        lda     sprite_x                        ; A774 A5 E3                    ..
        pha                                     ; A776 48                       H
        jsr     check_ship_collision            ; A777 20 FB B5                  ..
        pla                                     ; A77A 68                       h
        sta     sprite_x                        ; A77B 85 E3                    ..
        bcs     LA784                           ; A77D B0 05                    ..
LA77F:  lda     $88                             ; A77F A5 88                    ..
        jmp     draw_sprite_left_copy           ; A781 4C 00 1F                 L..

; ----------------------------------------------------------------------------
LA784:  sec                                     ; A784 38                       8
        rts                                     ; A785 60                       `

; ----------------------------------------------------------------------------
; XXX wrapper for erase_sprite, dunno why yet
erase_sprite_XXX:
        sec                                     ; A786 38                       8
        lda     $DD                             ; A787 A5 DD                    ..
        sbc     $8B                             ; A789 E5 8B                    ..
        sta     sprite_x                        ; A78B 85 E3                    ..
        lda     $DE                             ; A78D A5 DE                    ..
        sbc     $8C                             ; A78F E5 8C                    ..
        sta     $E4                             ; A791 85 E4                    ..
        bcs     LA7A1                           ; A793 B0 0C                    ..
        lda     sprite_x                        ; A795 A5 E3                    ..
        adc     #$80                            ; A797 69 80                    i.
        sta     sprite_x                        ; A799 85 E3                    ..
        lda     $E4                             ; A79B A5 E4                    ..
        adc     #$02                            ; A79D 69 02                    i.
        sta     $E4                             ; A79F 85 E4                    ..
LA7A1:  lda     $E4                             ; A7A1 A5 E4                    ..
        bne     LA784                           ; A7A3 D0 DF                    ..
        lda     sprite_x                        ; A7A5 A5 E3                    ..
        cmp     #$A0                            ; A7A7 C9 A0                    ..
        bcs     LA784                           ; A7A9 B0 D9                    ..
        jmp     erase_sprite                    ; A7AB 4C 2C AB                 L,.

; ----------------------------------------------------------------------------
; add points to score based on what kind of enemy we killed. does not include points for rescued humans nor end-of-level bonus.
add_cursprite_points:
        lda     current_sprite                  ; A7AE A5 F9                    ..
        and     #$07                            ; A7B0 29 07                    ).
; this entry point takes a sprite type in A, used for end-of-level bonus (and...?)
add_points:
        asl     a                               ; A7B2 0A                       .
        tay                                     ; A7B3 A8                       .
        clc                                     ; A7B4 18                       .
        lda     score_points_table,y            ; A7B5 B9 FD A7                 ...
        adc     score                           ; A7B8 6D 2F 14                 m/.
        sta     score                           ; A7BB 8D 2F 14                 ./.
        cmp     #$64                            ; A7BE C9 64                    .d
        bcc     LA7CA                           ; A7C0 90 08                    ..
        sbc     #$64                            ; A7C2 E9 64                    .d
        sta     score                           ; A7C4 8D 2F 14                 ./.
        inc     score+1                         ; A7C7 EE 30 14                 .0.
LA7CA:  clc                                     ; A7CA 18                       .
        lda     score_points_table+1,y          ; A7CB B9 FE A7                 ...
        adc     score+1                         ; A7CE 6D 30 14                 m0.
        sta     score+1                         ; A7D1 8D 30 14                 .0.
        cmp     #$64                            ; A7D4 C9 64                    .d
; if score+1 rolled over $63 => 0, we passed 10K points. note that *all* changes to the score pass through here, so this check is always done.
check_extra_life:
        bcc     aep_done                        ; A7D6 90 22                    ."
        sbc     #$64                            ; A7D8 E9 64                    .d
        sta     score+1                         ; A7DA 8D 30 14                 .0.
        inc     score+2                         ; A7DD EE 31 14                 .1.
        txa                                     ; A7E0 8A                       .
        pha                                     ; A7E1 48                       H
        jsr     play_extra_life                 ; A7E2 20 5C 8E                  \.
        pla                                     ; A7E5 68                       h
        tax                                     ; A7E6 AA                       .
        inc     lives                           ; A7E7 E6 9E                    ..
        inc     smartbombs                      ; A7E9 E6 A5                    ..
        lda     score+2                         ; A7EB AD 31 14                 .1.
        cmp     #$64                            ; A7EE C9 64                    .d
        bcc     aep_done                        ; A7F0 90 08                    ..
        sbc     #$64                            ; A7F2 E9 64                    .d
        sta     score+2                         ; A7F4 8D 31 14                 .1.
        inc     score+3                         ; A7F7 EE 32 14                 .2.
aep_done:
        lsr     $AD                             ; A7FA 46 AD                    F.
        rts                                     ; A7FC 60                       `

; ----------------------------------------------------------------------------
; binary base 100. msb first (unlike score!). 0132 = 100*$01+$32 = 150 decimal. order: human (0), lander (150), mutant (150), enemy shot or bomber bomb (25, only by colliding with ship), bomber (250), pod (1000), swarmer (200), baiter (200), rest are bonus
score_points_table:
        .word   $0000,$0132,$0132,$0019         ; A7FD 00 00 32 01 32 01 19 00  ..2.2...
        .word   $0232,$0A00,$0200,$0200         ; A805 32 02 00 0A 00 02 00 02  2.......
        .word   $0100,$0200,$0300,$0400         ; A80D 00 01 00 02 00 03 00 04  ........
        .word   $0500                           ; A815 00 05                    ..
; ----------------------------------------------------------------------------
LA817:  ldy     #$00                            ; A817 A0 00                    ..
LA819:  jsr     get_random                      ; A819 20 F2 8C                  ..
        and     #$7F                            ; A81C 29 7F                    ).
        adc     #$20                            ; A81E 69 20                    i 
        sta     $0C2B,y                         ; A820 99 2B 0C                 .+.
        jsr     get_random                      ; A823 20 F2 8C                  ..
        and     #$7F                            ; A826 29 7F                    ).
        sta     $0C2C,y                         ; A828 99 2C 0C                 .,.
        iny                                     ; A82B C8                       .
        iny                                     ; A82C C8                       .
        cpy     #$20                            ; A82D C0 20                    . 
        bcc     LA819                           ; A82F 90 E8                    ..
        rts                                     ; A831 60                       `

; ----------------------------------------------------------------------------
; XXX don't know how this works yet
animate_starfield:
        jsr     get_random                      ; A832 20 F2 8C                  ..
        lda     $95                             ; A835 A5 95                    ..
        clc                                     ; A837 18                       .
        adc     #$02                            ; A838 69 02                    i.
        sta     $95                             ; A83A 85 95                    ..
        cmp     #$20                            ; A83C C9 20                    . 
        bcc     LA844                           ; A83E 90 04                    ..
        lda     #$00                            ; A840 A9 00                    ..
        sta     $95                             ; A842 85 95                    ..
LA844:  ldy     $95                             ; A844 A4 95                    ..
        lda     $0C2B,y                         ; A846 B9 2B 0C                 .+.
        sta     sprite_y                        ; A849 85 DF                    ..
        ldx     $0C2C,y                         ; A84B BE 2C 0C                 .,.
        stx     $DD                             ; A84E 86 DD                    ..
        tay                                     ; A850 A8                       .
        lda     screen_hi_ptrs,y                ; A851 B9 00 1E                 ...
        sta     screen_ptr+1                    ; A854 85 C1                    ..
        lda     screen_lo_ptrs,y                ; A856 B9 00 1D                 ...
        sta     screen_ptr                      ; A859 85 C0                    ..
        lda     #$00                            ; A85B A9 00                    ..
        ldy     horiz_offset_table,x            ; A85D BC 00 1B                 ...
        sta     (screen_ptr),y                  ; A860 91 C0                    ..
        lda     $95                             ; A862 A5 95                    ..
        and     #$02                            ; A864 29 02                    ).
        bne     LA874                           ; A866 D0 0C                    ..
        lda     random_seed+1                   ; A868 A5 C7                    ..
        and     #$1F                            ; A86A 29 1F                    ).
        bne     LA874                           ; A86C D0 06                    ..
        lda     random_seed                     ; A86E A5 C6                    ..
        and     #$7F                            ; A870 29 7F                    ).
        sta     $DD                             ; A872 85 DD                    ..
LA874:  lda     ship_delta                      ; A874 A5 D5                    ..
        bpl     LA88C                           ; A876 10 14                    ..
        eor     #$FF                            ; A878 49 FF                    I.
        clc                                     ; A87A 18                       .
        adc     #$01                            ; A87B 69 01                    i.
        adc     $DD                             ; A87D 65 DD                    e.
        sta     $DD                             ; A87F 85 DD                    ..
        cmp     #$A0                            ; A881 C9 A0                    ..
        bcc     LA899                           ; A883 90 14                    ..
        sbc     #$A0                            ; A885 E9 A0                    ..
        sta     $DD                             ; A887 85 DD                    ..
        jmp     LA899                           ; A889 4C 99 A8                 L..

; ----------------------------------------------------------------------------
LA88C:  lda     $DD                             ; A88C A5 DD                    ..
        sec                                     ; A88E 38                       8
        sbc     ship_delta                      ; A88F E5 D5                    ..
        sta     $DD                             ; A891 85 DD                    ..
        bcs     LA899                           ; A893 B0 04                    ..
        adc     #$A0                            ; A895 69 A0                    i.
        sta     $DD                             ; A897 85 DD                    ..
LA899:  ldy     $95                             ; A899 A4 95                    ..
        lda     $DD                             ; A89B A5 DD                    ..
        sta     $0C2C,y                         ; A89D 99 2C 0C                 .,.
        lda     random_seed                     ; A8A0 A5 C6                    ..
        and     #$07                            ; A8A2 29 07                    ).
        beq     LA8B2                           ; A8A4 F0 0C                    ..
        ldx     $DD                             ; A8A6 A6 DD                    ..
        lda     random_seed                     ; A8A8 A5 C6                    ..
        and     pixel_mask_table,x              ; A8AA 3D 00 1C                 =..
        ldy     horiz_offset_table,x            ; A8AD BC 00 1B                 ...
        sta     (screen_ptr),y                  ; A8B0 91 C0                    ..
LA8B2:  rts                                     ; A8B2 60                       `

; ----------------------------------------------------------------------------
; single-wide, non-animated, copied to $0d2f
sprom_humanoid:
        .byte   $28,$00,$28,$00,$14,$00,$14,$00 ; A8B3 28 00 28 00 14 00 14 00  (.(.....
        .byte   $14,$00,$0C,$00,$0C,$00,$0C,$00 ; A8BB 14 00 0C 00 0C 00 0C 00  ........
; single-wide, animated, copied to $0d6f
sprom_lander_1:
        .byte   $00,$00,$15,$00,$44,$40,$44,$40 ; A8C3 00 00 15 00 44 40 44 40  ....D@D@
        .byte   $15,$00,$04,$00,$15,$00,$44,$40 ; A8CB 15 00 04 00 15 00 44 40  ......D@
; copied to $0daf
sprom_lander_2:
        .byte   $1F,$00,$15,$00,$51,$40,$51,$40 ; A8D3 1F 00 15 00 51 40 51 40  ....Q@Q@
        .byte   $15,$00,$04,$00,$15,$00,$44,$40 ; A8DB 15 00 04 00 15 00 44 40  ......D@
; single-wide, animated, copied to $0def
sprom_mutant_1:
        .byte   $3C,$00,$3D,$00,$6A,$40,$6A,$40 ; A8E3 3C 00 3D 00 6A 40 6A 40  <.=.j@j@
        .byte   $6A,$40,$2A,$00,$19,$00,$48,$40 ; A8EB 6A 40 2A 00 19 00 48 40  j@*...H@
; copied to $0e2f
sprom_mutant_2:
        .byte   $00,$00,$11,$00,$6A,$40,$6A,$40 ; A8F3 00 00 11 00 6A 40 6A 40  ....j@j@
        .byte   $6A,$40,$2A,$00,$19,$00,$48,$40 ; A8FB 6A 40 2A 00 19 00 48 40  j@*...H@
; right-facing ship, double-wide, animated, copied to $0e6f
sprom_rship_l_1:
        .byte   $30,$00,$F4,$00,$EC,$00,$AF,$80 ; A903 30 00 F4 00 EC 00 AF 80  0.......
        .byte   $EB,$80,$AB,$C0,$EB,$C0,$AF,$C0 ; A90B EB 80 AB C0 EB C0 AF C0  ........
; copied to $0eaf
sprom_rship_r_1:
        .byte   $00,$00,$00,$00,$00,$00,$88,$00 ; A913 00 00 00 00 00 00 88 00  ........
        .byte   $88,$00,$FF,$C0,$FC,$00,$00,$00 ; A91B 88 00 FF C0 FC 00 00 00  ........
; copied to $0eef
sprom_rship_l_2:
        .byte   $30,$00,$F4,$00,$BC,$00,$EF,$80 ; A923 30 00 F4 00 BC 00 EF 80  0.......
        .byte   $AB,$80,$EA,$C0,$AB,$C0,$AF,$C0 ; A92B AB 80 EA C0 AB C0 AF C0  ........
; copied to $0f2f
sprom_rship_r_2:
        .byte   $00,$00,$00,$00,$00,$00,$20,$00 ; A933 00 00 00 00 00 00 20 00  ...... .
        .byte   $28,$00,$FF,$C0,$FC,$00,$00,$00 ; A93B 28 00 FF C0 FC 00 00 00  (.......
; left-facing ship, double-wide, animated, copied to $0f6f
sprom_lship_l_1:
        .byte   $00,$00,$00,$00,$00,$00,$08,$80 ; A943 00 00 00 00 00 00 08 80  ........
        .byte   $08,$80,$FF,$C0,$0F,$C0,$00,$00 ; A94B 08 80 FF C0 0F C0 00 00  ........
; copied to $0faf
sprom_lship_r_1:
        .byte   $03,$00,$07,$C0,$0E,$C0,$BE,$80 ; A953 03 00 07 C0 0E C0 BE 80  ........
        .byte   $BA,$C0,$FA,$80,$FA,$C0,$FE,$80 ; A95B BA C0 FA 80 FA C0 FE 80  ........
; copied to $0fef
sprom_lship_l_2:
        .byte   $00,$00,$00,$00,$00,$00,$02,$00 ; A963 00 00 00 00 00 00 02 00  ........
        .byte   $0A,$00,$FF,$C0,$0F,$C0,$00,$00 ; A96B 0A 00 FF C0 0F C0 00 00  ........
; copied to $102f
sprom_lship_r_2:
        .byte   $03,$00,$07,$C0,$0E,$C0,$0F,$80 ; A973 03 00 07 C0 0E C0 0F 80  ........
        .byte   $BA,$80,$FA,$C0,$FA,$80,$FE,$80 ; A97B BA 80 FA C0 FA 80 FE 80  ........
; enemy shot, single-wide, non-animated, copied to $106f
sprom_bullet:
        .byte   $30,$00,$FC,$00,$FC,$00,$30,$00 ; A983 30 00 FC 00 FC 00 30 00  0.....0.
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; A98B 00 00 00 00 00 00 00 00  ........
; single-wide, animated, copied to $10af
sprom_bomber_1:
        .byte   $2A,$80,$2A,$80,$80,$80,$8C,$80 ; A993 2A 80 2A 80 80 80 8C 80  *.*.....
        .byte   $8C,$80,$82,$80,$AA,$00,$00,$00 ; A99B 8C 80 82 80 AA 00 00 00  ........
; copied to $10ef
sprom_bomber_2:
        .byte   $2A,$80,$2A,$80,$FE,$80,$CE,$80 ; A9A3 2A 80 2A 80 FE 80 CE 80  *.*.....
        .byte   $CE,$80,$FE,$80,$AA,$00,$00,$00 ; A9AB CE 80 FE 80 AA 00 00 00  ........
; bomber's bomb, single-wide, non-animated, copied to $112f
sprom_xbomb:
        .byte   $44,$00,$10,$00,$44,$00,$00,$00 ; A9B3 44 00 10 00 44 00 00 00  D...D...
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; A9BB 00 00 00 00 00 00 00 00  ........
; player's exhaust flame, right-facing, single-wide, animated, copied to $11ef
sprom_rflame_1:
        .byte   $00,$00,$02,$80,$0A,$80,$2A,$C0 ; A9C3 00 00 02 80 0A 80 2A C0  ......*.
        .byte   $AB,$00,$2A,$C0,$0A,$80,$02,$80 ; A9CB AB 00 2A C0 0A 80 02 80  ..*.....
; copied to $122f
sprom_rflame_2:
        .byte   $00,$00,$00,$00,$00,$00,$0A,$00 ; A9D3 00 00 00 00 00 00 0A 00  ........
        .byte   $22,$00,$0A,$00,$00,$00,$00,$00 ; A9DB 22 00 0A 00 00 00 00 00  ".......
; player's exhaust flame, left-facing, single-wide, animated, copied to $116f
sprom_lflame_1:
        .byte   $00,$00,$A0,$00,$A8,$00,$EA,$00 ; A9E3 00 00 A0 00 A8 00 EA 00  ........
        .byte   $3A,$80,$EA,$00,$A8,$00,$A0,$00 ; A9EB 3A 80 EA 00 A8 00 A0 00  :.......
; copied to $11af
sprom_lflame_2:
        .byte   $00,$00,$00,$00,$00,$00,$28,$00 ; A9F3 00 00 00 00 00 00 28 00  ......(.
        .byte   $22,$00,$28,$00,$00,$00,$00,$00 ; A9FB 22 00 28 00 00 00 00 00  ".(.....
; single-wide, animated, copied to $126f
sprom_pod_1:
        .byte   $C8,$C0,$2A,$00,$2A,$00,$AE,$80 ; AA03 C8 C0 2A 00 2A 00 AE 80  ..*.*...
        .byte   $2A,$00,$2A,$00,$C8,$C0,$00,$00 ; AA0B 2A 00 2A 00 C8 C0 00 00  *.*.....
; copied to $12af
sprom_pod_2:
        .byte   $0C,$00,$AA,$80,$AE,$80,$E2,$C0 ; AA13 0C 00 AA 80 AE 80 E2 C0  ........
        .byte   $AE,$80,$AA,$80,$0C,$00,$00,$00 ; AA1B AE 80 AA 80 0C 00 00 00  ........
; single-wide, non-animated, copied to $12ef
sprom_swarmer:
        .byte   $08,$00,$2A,$00,$96,$80,$2A,$00 ; AA23 08 00 2A 00 96 80 2A 00  ..*...*.
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; AA2B 00 00 00 00 00 00 00 00  ........
; double-wide, non-animated, copied to $132f
sprom_baiter_l:
        .byte   $01,$40,$08,$00,$28,$80,$55,$40 ; AA33 01 40 08 00 28 80 55 40  .@..(.U@
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; AA3B 00 00 00 00 00 00 00 00  ........
; copied to $136f
sprom_baiter_r:
        .byte   $50,$00,$88,$00,$8A,$00,$55,$40 ; AA43 50 00 88 00 8A 00 55 40  P.....U@
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; AA4B 00 00 00 00 00 00 00 00  ........
; single-wide, animated, copied to $13af
sprom_smartbomb_1:
        .byte   $3C,$C0,$A3,$00,$3C,$C0,$00,$00 ; AA53 3C C0 A3 00 3C C0 00 00  <...<...
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; AA5B 00 00 00 00 00 00 00 00  ........
; copied to $13ef
sprom_smartbomb_2:
        .byte   $3C,$C0,$03,$00,$3C,$C0,$00,$00 ; AA63 3C C0 03 00 3C C0 00 00  <...<...
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; AA6B 00 00 00 00 00 00 00 00  ........
; XXX what (if anything) is this used for?
table_aa73:
        .byte   $02,$BB,$5A,$30,$5F,$EE,$3D,$A8 ; AA73 02 BB 5A 30 5F EE 3D A8  ..Z0_.=.
; ----------------------------------------------------------------------------
; draw left half of ship, enemy, projectile, bomb, human. copied to RAM at draw_sprite_left_copy and called there.
draw_sprite_left:
        asl     a                               ; AA7B 0A                       .
        tay                                     ; AA7C A8                       .
        lda     sprite_ram_addrs,y              ; AA7D B9 57 AB                 .W.
; modify operands of (the RAM copies of) instructions marked with HERE
dsl_selfmod_lo:
        sta     draw_sprite_left_copy+67        ; AA80 8D 43 1F                 .C.
        sta     draw_sprite_left_copy+77        ; AA83 8D 4D 1F                 .M.
        lda     sprite_ram_addrs+1,y            ; AA86 B9 58 AB                 .X.
; modify operands of (the RAM copies of) instructions marked with HERE
dsl_selfmod_hi:
        sta     draw_sprite_left_copy+68        ; AA89 8D 44 1F                 .D.
        sta     draw_sprite_left_copy+78        ; AA8C 8D 4E 1F                 .N.
        lda     sprite_y                        ; AA8F A5 DF                    ..
        sta     tmp_y                           ; AA91 85 82                    ..
        ldx     sprite_x                        ; AA93 A6 E3                    ..
        lda     horiz_offset_table,x            ; AA95 BD 00 1B                 ...
        sta     tmp_hoffset_l                   ; AA98 85 83                    ..
        lda     horiz_offset_table+4,x          ; AA9A BD 04 1B                 ...
        sta     tmp_hoffset_r                   ; AA9D 85 B8                    ..
        ldy     offset_index_table,x            ; AA9F BC 00 1A                 ...
        ldx     sprite_table_offsets,y          ; AAA2 BE 8F AB                 ...
        lda     current_sprite                  ; AAA5 A5 F9                    ..
        and     #$07                            ; AAA7 29 07                    ).
        tay                                     ; AAA9 A8                       .
        lda     sprite_heights,y                ; AAAA B9 97 AB                 ...
        sta     tmp_height                      ; AAAD 85 84                    ..
dsl_loop:
        ldy     tmp_y                           ; AAAF A4 82                    ..
        lda     screen_hi_ptrs,y                ; AAB1 B9 00 1E                 ...
        sta     screen_ptr+1                    ; AAB4 85 C1                    ..
        lda     screen_lo_ptrs,y                ; AAB6 B9 00 1D                 ...
        sta     screen_ptr                      ; AAB9 85 C0                    ..
        ldy     tmp_hoffset_l                   ; AABB A4 83                    ..
; operand gets modified
dsl_HERE_1:
        lda     sprom_humanoid,x                ; AABD BD B3 A8                 ...
        ora     (screen_ptr),y                  ; AAC0 11 C0                    ..
        sta     (screen_ptr),y                  ; AAC2 91 C0                    ..
        ldy     tmp_hoffset_r                   ; AAC4 A4 B8                    ..
        inx                                     ; AAC6 E8                       .
; operand gets modified
dsl_HERE_2:
        lda     sprom_humanoid,x                ; AAC7 BD B3 A8                 ...
        ora     (screen_ptr),y                  ; AACA 11 C0                    ..
        sta     (screen_ptr),y                  ; AACC 91 C0                    ..
        inx                                     ; AACE E8                       .
        inc     tmp_y                           ; AACF E6 82                    ..
        dec     tmp_height                      ; AAD1 C6 84                    ..
        bne     dsl_loop                        ; AAD3 D0 DA                    ..
        clc                                     ; AAD5 18                       .
        rts                                     ; AAD6 60                       `

; ----------------------------------------------------------------------------
; draw right half of ship, enemy, projectile, bomb, human. copied to RAM at draw_sprite_right_copy and called there.
draw_sprite_right:
        asl     a                               ; AAD7 0A                       .
        tay                                     ; AAD8 A8                       .
        lda     sprite_ram_addrs,y              ; AAD9 B9 57 AB                 .W.
; modify operands of (the RAM copies of) instructions marked with HERE
dsr_selfmod_lo:
        sta     draw_sprite_right_copy+61       ; AADC 8D BD 1F                 ...
        sta     draw_sprite_right_copy+71       ; AADF 8D C7 1F                 ...
        lda     sprite_ram_addrs+1,y            ; AAE2 B9 58 AB                 .X.
; modify operands of (the RAM copies of) instructions marked with HERE
dsr_selfmod_hi:
        sta     draw_sprite_right_copy+62       ; AAE5 8D BE 1F                 ...
        sta     draw_sprite_right_copy+72       ; AAE8 8D C8 1F                 ...
        lda     sprite_y                        ; AAEB A5 DF                    ..
        sta     tmp_y                           ; AAED 85 82                    ..
        ldx     sprite_x                        ; AAEF A6 E3                    ..
        lda     horiz_offset_table,x            ; AAF1 BD 00 1B                 ...
        sta     tmp_hoffset_l                   ; AAF4 85 83                    ..
        lda     horiz_offset_table+4,x          ; AAF6 BD 04 1B                 ...
        sta     tmp_hoffset_r                   ; AAF9 85 B8                    ..
        ldy     offset_index_table,x            ; AAFB BC 00 1A                 ...
        ldx     sprite_table_offsets,y          ; AAFE BE 8F AB                 ...
        lda     #$08                            ; AB01 A9 08                    ..
        sta     tmp_height                      ; AB03 85 84                    ..
dsr_loop:
        ldy     tmp_y                           ; AB05 A4 82                    ..
        lda     screen_hi_ptrs,y                ; AB07 B9 00 1E                 ...
        sta     screen_ptr+1                    ; AB0A 85 C1                    ..
        lda     screen_lo_ptrs,y                ; AB0C B9 00 1D                 ...
        sta     screen_ptr                      ; AB0F 85 C0                    ..
        ldy     tmp_hoffset_l                   ; AB11 A4 83                    ..
; operand gets modified
dsr_HERE_1:
        lda     sprom_humanoid,x                ; AB13 BD B3 A8                 ...
        ora     (screen_ptr),y                  ; AB16 11 C0                    ..
        sta     (screen_ptr),y                  ; AB18 91 C0                    ..
        ldy     tmp_hoffset_r                   ; AB1A A4 B8                    ..
        inx                                     ; AB1C E8                       .
; operand gets modified
dsr_HERE_2:
        lda     sprom_humanoid,x                ; AB1D BD B3 A8                 ...
        ora     (screen_ptr),y                  ; AB20 11 C0                    ..
        sta     (screen_ptr),y                  ; AB22 91 C0                    ..
        inx                                     ; AB24 E8                       .
        inc     tmp_y                           ; AB25 E6 82                    ..
        dec     tmp_height                      ; AB27 C6 84                    ..
        bne     dsr_loop                        ; AB29 D0 DA                    ..
        rts                                     ; AB2B 60                       `

; ----------------------------------------------------------------------------
; zero out memory to avoid leaving trails
erase_sprite:
        ldx     sprite_y                        ; AB2C A6 DF                    ..
        lda     current_sprite                  ; AB2E A5 F9                    ..
        and     #$07                            ; AB30 29 07                    ).
        tay                                     ; AB32 A8                       .
        lda     sprite_heights,y                ; AB33 B9 97 AB                 ...
        sta     tmp_height                      ; AB36 85 84                    ..
        ldy     sprite_x                        ; AB38 A4 E3                    ..
        lda     horiz_offset_table,y            ; AB3A B9 00 1B                 ...
        tay                                     ; AB3D A8                       .
LAB3E:  lda     screen_hi_ptrs,x                ; AB3E BD 00 1E                 ...
        sta     screen_ptr+1                    ; AB41 85 C1                    ..
        lda     screen_lo_ptrs,x                ; AB43 BD 00 1D                 ...
        sta     screen_ptr                      ; AB46 85 C0                    ..
        lda     #$00                            ; AB48 A9 00                    ..
        sta     (screen_ptr),y                  ; AB4A 91 C0                    ..
        iny                                     ; AB4C C8                       .
        sta     (screen_ptr),y                  ; AB4D 91 C0                    ..
        dey                                     ; AB4F 88                       .
        inx                                     ; AB50 E8                       .
        dec     tmp_height                      ; AB51 C6 84                    ..
        bne     LAB3E                           ; AB53 D0 E9                    ..
        clc                                     ; AB55 18                       .
        rts                                     ; AB56 60                       `

; ----------------------------------------------------------------------------
; used by draw_sprite_(left|right)
sprite_ram_addrs:
        .addr   sp_humanoid                     ; AB57 2F 0D                    /.
        .addr   sp_lander_1                     ; AB59 6F 0D                    o.
        .addr   sp_lander_2                     ; AB5B AF 0D                    ..
        .addr   sp_mutant_1                     ; AB5D EF 0D                    ..
        .addr   sp_mutant_2                     ; AB5F 2F 0E                    /.
        .addr   sp_rship_l_1                    ; AB61 6F 0E                    o.
        .addr   sp_rship_r_1                    ; AB63 AF 0E                    ..
        .addr   sp_rship_l_2                    ; AB65 EF 0E                    ..
        .addr   sp_rship_r_2                    ; AB67 2F 0F                    /.
        .addr   sp_lship_l_1                    ; AB69 6F 0F                    o.
        .addr   sp_lship_r_1                    ; AB6B AF 0F                    ..
        .addr   sp_lship_l_2                    ; AB6D EF 0F                    ..
        .addr   sp_lship_r_2                    ; AB6F 2F 10                    /.
        .addr   sp_bullet                       ; AB71 6F 10                    o.
        .addr   sp_bomber_1                     ; AB73 AF 10                    ..
        .addr   sp_bomber_2                     ; AB75 EF 10                    ..
        .addr   sp_xbomb                        ; AB77 2F 11                    /.
        .addr   sp_lflame_1                     ; AB79 6F 11                    o.
        .addr   sp_lflame_2                     ; AB7B AF 11                    ..
        .addr   sp_rflame_1                     ; AB7D EF 11                    ..
        .addr   sp_rflame_2                     ; AB7F 2F 12                    /.
        .addr   sp_pod_1                        ; AB81 6F 12                    o.
        .addr   sp_pod_2                        ; AB83 AF 12                    ..
        .addr   sp_swarmer                      ; AB85 EF 12                    ..
        .addr   sp_baiter_l                     ; AB87 2F 13                    /.
        .addr   sp_baiter_r                     ; AB89 6F 13                    o.
        .addr   sp_smartbomb_1                  ; AB8B AF 13                    ..
        .addr   sp_smartbomb_2                  ; AB8D EF 13                    ..
; ----------------------------------------------------------------------------
; basically just a mul-by-16 table
sprite_table_offsets:
        .byte   $00,$10,$20,$30,$40,$50,$60,$70 ; AB8F 00 10 20 30 40 50 60 70  .. 0@P`p
; used to avoid drawing extra empty sprite rows, if they're shorter than full height
sprite_heights:
        .byte   $08,$08,$08,$04,$07,$07,$04,$04 ; AB97 08 08 08 04 07 07 04 04  ........
; ----------------------------------------------------------------------------
; create right-shifted copy of a sprite, 1-3 pixels, at sp_x+$10, sp_x+$20, sp_x+$30
preshift_sprite:
        ldx     #$00                            ; AB9F A2 00                    ..
        lda     #$01                            ; ABA1 A9 01                    ..
        sta     sprite_x                        ; ABA3 85 E3                    ..
        ldy     #$00                            ; ABA5 A0 00                    ..
LABA7:  lda     (preshift_ptr),y                ; ABA7 B1 80                    ..
        sta     pss_temp,x                      ; ABA9 9D 4B 0C                 .K.
        iny                                     ; ABAC C8                       .
        inx                                     ; ABAD E8                       .
        cpx     #$10                            ; ABAE E0 10                    ..
        bcc     LABA7                           ; ABB0 90 F5                    ..
LABB2:  lda     #$08                            ; ABB2 A9 08                    ..
        sta     tmp_height                      ; ABB4 85 84                    ..
        lda     #$02                            ; ABB6 A9 02                    ..
        sta     tmp_y                           ; ABB8 85 82                    ..
        jsr     LABD9                           ; ABBA 20 D9 AB                  ..
        ldy     sprite_x                        ; ABBD A4 E3                    ..
        lda     sprite_table_offsets,y          ; ABBF B9 8F AB                 ...
        tay                                     ; ABC2 A8                       .
        ldx     #$00                            ; ABC3 A2 00                    ..
LABC5:  lda     pss_temp,x                      ; ABC5 BD 4B 0C                 .K.
        sta     (preshift_ptr),y                ; ABC8 91 80                    ..
        iny                                     ; ABCA C8                       .
        inx                                     ; ABCB E8                       .
        cpx     #$10                            ; ABCC E0 10                    ..
        bcc     LABC5                           ; ABCE 90 F5                    ..
        inc     sprite_x                        ; ABD0 E6 E3                    ..
        lda     sprite_x                        ; ABD2 A5 E3                    ..
        cmp     #$04                            ; ABD4 C9 04                    ..
        bcc     LABB2                           ; ABD6 90 DA                    ..
        rts                                     ; ABD8 60                       `

; ----------------------------------------------------------------------------
LABD9:  ldx     #$00                            ; ABD9 A2 00                    ..
LABDB:  ldy     #$02                            ; ABDB A0 02                    ..
LABDD:  lsr     pss_temp,x                      ; ABDD 5E 4B 0C                 ^K.
        ror     $0C4C,x                         ; ABE0 7E 4C 0C                 ~L.
        dey                                     ; ABE3 88                       .
        bne     LABDD                           ; ABE4 D0 F7                    ..
        inx                                     ; ABE6 E8                       .
        inx                                     ; ABE7 E8                       .
        dec     tmp_height                      ; ABE8 C6 84                    ..
        bne     LABDB                           ; ABEA D0 EF                    ..
        rts                                     ; ABEC 60                       `

; ----------------------------------------------------------------------------
; XXX does this apply to humanoids too?
spawn_sprite:
        ldy     #$00                            ; ABED A0 00                    ..
LABEF:  lda     actor_list,y                    ; ABEF B9 6B 0C                 .k.
        beq     LABFE                           ; ABF2 F0 0A                    ..
        tya                                     ; ABF4 98                       .
        clc                                     ; ABF5 18                       .
        adc     #$06                            ; ABF6 69 06                    i.
        tay                                     ; ABF8 A8                       .
        cpy     #$C0                            ; ABF9 C0 C0                    ..
        bcc     LABEF                           ; ABFB 90 F2                    ..
        rts                                     ; ABFD 60                       `

; ----------------------------------------------------------------------------
LABFE:  lda     sprite_y                        ; ABFE A5 DF                    ..
        sta     actor_list,y                    ; AC00 99 6B 0C                 .k.
        lda     $DD                             ; AC03 A5 DD                    ..
        sta     actor_list+1,y                  ; AC05 99 6C 0C                 .l.
        lda     $DE                             ; AC08 A5 DE                    ..
        sta     actor_list+2,y                  ; AC0A 99 6D 0C                 .m.
        lda     current_sprite                  ; AC0D A5 F9                    ..
        sta     actor_list+3,y                  ; AC0F 99 6E 0C                 .n.
        lda     #$30                            ; AC12 A9 30                    .0
        sta     actor_list+4,y                  ; AC14 99 6F 0C                 .o.
        rts                                     ; AC17 60                       `

; ----------------------------------------------------------------------------
LAC18:  lda     #$00                            ; AC18 A9 00                    ..
        sta     $86                             ; AC1A 85 86                    ..
        sta     baiter_count                    ; AC1C 85 9D                    ..
        jmp     LAC2D                           ; AC1E 4C 2D AC                 L-.

; ----------------------------------------------------------------------------
LAC21:  lda     $86                             ; AC21 A5 86                    ..
        clc                                     ; AC23 18                       .
        adc     #$06                            ; AC24 69 06                    i.
        sta     $86                             ; AC26 85 86                    ..
        cmp     #$C0                            ; AC28 C9 C0                    ..
        bcc     LAC2D                           ; AC2A 90 01                    ..
        rts                                     ; AC2C 60                       `

; ----------------------------------------------------------------------------
LAC2D:  ldy     $86                             ; AC2D A4 86                    ..
        lda     actor_list,y                    ; AC2F B9 6B 0C                 .k.
        beq     LAC21                           ; AC32 F0 ED                    ..
        sta     $CA                             ; AC34 85 CA                    ..
        lda     actor_list+3,y                  ; AC36 B9 6E 0C                 .n.
        and     #$07                            ; AC39 29 07                    ).
        cmp     #$07                            ; AC3B C9 07                    ..
        beq     LAC41                           ; AC3D F0 02                    ..
        inc     baiter_count                    ; AC3F E6 9D                    ..
LAC41:  sec                                     ; AC41 38                       8
        lda     actor_list+1,y                  ; AC42 B9 6C 0C                 .l.
        sbc     $8B                             ; AC45 E5 8B                    ..
        sta     sprite_x                        ; AC47 85 E3                    ..
        lda     actor_list+2,y                  ; AC49 B9 6D 0C                 .m.
        sbc     $8C                             ; AC4C E5 8C                    ..
        sta     $E4                             ; AC4E 85 E4                    ..
        bcs     LAC5E                           ; AC50 B0 0C                    ..
        lda     sprite_x                        ; AC52 A5 E3                    ..
        adc     #$80                            ; AC54 69 80                    i.
        sta     sprite_x                        ; AC56 85 E3                    ..
        lda     $E4                             ; AC58 A5 E4                    ..
        adc     #$02                            ; AC5A 69 02                    i.
        sta     $E4                             ; AC5C 85 E4                    ..
LAC5E:  lda     $E4                             ; AC5E A5 E4                    ..
        bne     LAC74                           ; AC60 D0 12                    ..
        lda     sprite_x                        ; AC62 A5 E3                    ..
        cmp     #$A0                            ; AC64 C9 A0                    ..
        bcs     LAC74                           ; AC66 B0 0C                    ..
        lda     sprite_x                        ; AC68 A5 E3                    ..
        sta     $C9                             ; AC6A 85 C9                    ..
        lda     actor_list+4,y                  ; AC6C B9 6F 0C                 .o.
        sta     $CB                             ; AC6F 85 CB                    ..
        jsr     L9C6C                           ; AC71 20 6C 9C                  l.
LAC74:  ldx     $86                             ; AC74 A6 86                    ..
        lda     actor_list+4,x                  ; AC76 BD 6F 0C                 .o.
        sec                                     ; AC79 38                       8
        sbc     #$04                            ; AC7A E9 04                    ..
        sta     actor_list+4,x                  ; AC7C 9D 6F 0C                 .o.
        bne     LACA7                           ; AC7F D0 26                    .&
        lda     actor_list,x                    ; AC81 BD 6B 0C                 .k.
        sta     sprite_y                        ; AC84 85 DF                    ..
        lda     #$00                            ; AC86 A9 00                    ..
        sta     actor_list,x                    ; AC88 9D 6B 0C                 .k.
        lda     actor_list+1,x                  ; AC8B BD 6C 0C                 .l.
        sta     $DD                             ; AC8E 85 DD                    ..
        lda     actor_list+2,x                  ; AC90 BD 6D 0C                 .m.
        sta     $DE                             ; AC93 85 DE                    ..
        lda     actor_list+3,x                  ; AC95 BD 6E 0C                 .n.
        sta     current_sprite                  ; AC98 85 F9                    ..
        jsr     add_to_sprite_list              ; AC9A 20 A5 A4                  ..
        bcs     LACA4                           ; AC9D B0 05                    ..
        lda     #$00                            ; AC9F A9 00                    ..
        sta     sprite_list+128,y               ; ACA1 99 6B 0B                 .k.
LACA4:  jmp     LAC21                           ; ACA4 4C 21 AC                 L!.

; ----------------------------------------------------------------------------
LACA7:  sec                                     ; ACA7 38                       8
        lda     actor_list+1,x                  ; ACA8 BD 6C 0C                 .l.
        sbc     $89                             ; ACAB E5 89                    ..
        sta     sprite_x                        ; ACAD 85 E3                    ..
        lda     actor_list+2,x                  ; ACAF BD 6D 0C                 .m.
        sbc     $8A                             ; ACB2 E5 8A                    ..
        sta     $E4                             ; ACB4 85 E4                    ..
        bcs     LACC4                           ; ACB6 B0 0C                    ..
        lda     sprite_x                        ; ACB8 A5 E3                    ..
        adc     #$80                            ; ACBA 69 80                    i.
        sta     sprite_x                        ; ACBC 85 E3                    ..
        lda     $E4                             ; ACBE A5 E4                    ..
        adc     #$02                            ; ACC0 69 02                    i.
        sta     $E4                             ; ACC2 85 E4                    ..
LACC4:  lda     $E4                             ; ACC4 A5 E4                    ..
        bne     LACDA                           ; ACC6 D0 12                    ..
        lda     sprite_x                        ; ACC8 A5 E3                    ..
        cmp     #$A0                            ; ACCA C9 A0                    ..
        bcs     LACDA                           ; ACCC B0 0C                    ..
        lda     sprite_x                        ; ACCE A5 E3                    ..
        sta     $C9                             ; ACD0 85 C9                    ..
        lda     actor_list+4,x                  ; ACD2 BD 6F 0C                 .o.
        sta     $CB                             ; ACD5 85 CB                    ..
        jsr     L9C62                           ; ACD7 20 62 9C                  b.
LACDA:  jmp     LAC21                           ; ACDA 4C 21 AC                 L!.

; ----------------------------------------------------------------------------
        ldy     #$00                            ; ACDD A0 00                    ..
LACDF:  lda     #$30                            ; ACDF A9 30                    .0
        sta     actor_list+4,y                  ; ACE1 99 6F 0C                 .o.
        tya                                     ; ACE4 98                       .
        clc                                     ; ACE5 18                       .
        adc     #$06                            ; ACE6 69 06                    i.
        tay                                     ; ACE8 A8                       .
        cpy     #$C0                            ; ACE9 C0 C0                    ..
        bcc     LACDF                           ; ACEB 90 F2                    ..
        rts                                     ; ACED 60                       `

; ----------------------------------------------------------------------------
; returns with carry clear if the ship moved, set if not. only checks one axis per call (vert or horiz). XXX magic constants and unknown locations used!
check_ship_move:
        inc     vert_horiz_flag                 ; ACEE EE 2C 0D                 .,.
        lda     vert_horiz_flag                 ; ACF1 AD 2C 0D                 .,.
        and     #$01                            ; ACF4 29 01                    ).
        php                                     ; ACF6 08                       .
        tax                                     ; ACF7 AA                       .
        jsr     read_joystick                   ; ACF8 20 B0 AD                  ..
        plp                                     ; ACFB 28                       (
        beq     check_horiz_move                ; ACFC F0 03                    ..
        jmp     check_vert_move                 ; ACFE 4C 85 AD                 L..

; ----------------------------------------------------------------------------
; check for right (a&$08) or left (a&$04) movement. remember Y holds the result of read_joystick (inverted PORT(A|B) value)
check_horiz_move:
        lsr     exhaust_flag                    ; AD01 4E 2B 0D                 N+.
        tya                                     ; AD04 98                       .
        and     #$0C                            ; AD05 29 0C                    ).
        cmp     #$08                            ; AD07 C9 08                    ..
        beq     thrust_right                    ; AD09 F0 1E                    ..
        cmp     #$04                            ; AD0B C9 04                    ..
        bne     thrust_left                     ; AD0D D0 55                    .U
        inc     inertia_counter                 ; AD0F EE 2D 0D                 .-.
        lda     inertia_counter                 ; AD12 AD 2D 0D                 .-.
        and     #$01                            ; AD15 29 01                    ).
        bne     apply_thrust                    ; AD17 D0 28                    .(
        ldx     horiz_acceleration              ; AD19 AE 2E 0D                 ...
        dex                                     ; AD1C CA                       .
        stx     horiz_acceleration              ; AD1D 8E 2E 0D                 ...
        bpl     apply_thrust                    ; AD20 10 1F                    ..
        inx                                     ; AD22 E8                       .
        stx     horiz_acceleration              ; AD23 8E 2E 0D                 ...
        jmp     apply_thrust                    ; AD26 4C 41 AD                 LA.

; ----------------------------------------------------------------------------
thrust_right:
        inc     inertia_counter                 ; AD29 EE 2D 0D                 .-.
        lda     inertia_counter                 ; AD2C AD 2D 0D                 .-.
        and     #$01                            ; AD2F 29 01                    ).
        bne     apply_thrust                    ; AD31 D0 0E                    ..
        ldx     horiz_acceleration              ; AD33 AE 2E 0D                 ...
        inx                                     ; AD36 E8                       .
        stx     horiz_acceleration              ; AD37 8E 2E 0D                 ...
        cpx     #$0F                            ; AD3A E0 0F                    ..
        bcc     apply_thrust                    ; AD3C 90 03                    ..
        dec     horiz_acceleration              ; AD3E CE 2E 0D                 ...
apply_thrust:
        ldx     horiz_acceleration              ; AD41 AE 2E 0D                 ...
        lda     accel_table,x                   ; AD44 BD A0 AD                 ...
        sta     ship_delta                      ; AD47 85 D5                    ..
        tya                                     ; AD49 98                       .
        and     #$0C                            ; AD4A 29 0C                    ).
        cmp     #$08                            ; AD4C C9 08                    ..
        beq     return_right                    ; AD4E F0 0C                    ..
        cmp     #$04                            ; AD50 C9 04                    ..
        bne     return_carry_set                ; AD52 D0 4A                    .J
        lda     #$88                            ; AD54 A9 88                    ..
        sec                                     ; AD56 38                       8
        ror     exhaust_flag                    ; AD57 6E 2B 0D                 n+.
        clc                                     ; AD5A 18                       .
        rts                                     ; AD5B 60                       `

; ----------------------------------------------------------------------------
return_right:
        lda     #$95                            ; AD5C A9 95                    ..
        sec                                     ; AD5E 38                       8
        ror     exhaust_flag                    ; AD5F 6E 2B 0D                 n+.
        clc                                     ; AD62 18                       .
        rts                                     ; AD63 60                       `

; ----------------------------------------------------------------------------
thrust_left:
        inc     inertia_counter                 ; AD64 EE 2D 0D                 .-.
        lda     inertia_counter                 ; AD67 AD 2D 0D                 .-.
        and     #$03                            ; AD6A 29 03                    ).
        bne     apply_thrust                    ; AD6C D0 D3                    ..
        ldx     horiz_acceleration              ; AD6E AE 2E 0D                 ...
        cpx     #$07                            ; AD71 E0 07                    ..
        beq     apply_thrust                    ; AD73 F0 CC                    ..
        bcc     thrust_ok                       ; AD75 90 07                    ..
        dex                                     ; AD77 CA                       .
        stx     horiz_acceleration              ; AD78 8E 2E 0D                 ...
        jmp     apply_thrust                    ; AD7B 4C 41 AD                 LA.

; ----------------------------------------------------------------------------
thrust_ok:
        inx                                     ; AD7E E8                       .
        stx     horiz_acceleration              ; AD7F 8E 2E 0D                 ...
        jmp     apply_thrust                    ; AD82 4C 41 AD                 LA.

; ----------------------------------------------------------------------------
; check for down (a&$02) or up (a&$01) movement
check_vert_move:
        tya                                     ; AD85 98                       .
        and     #$03                            ; AD86 29 03                    ).
        cmp     #$02                            ; AD88 C9 02                    ..
        beq     move_down                       ; AD8A F0 08                    ..
        cmp     #$01                            ; AD8C C9 01                    ..
        bne     no_vert_move                    ; AD8E D0 08                    ..
; XXX how does this work?
move_up:clc                                     ; AD90 18                       .
        lda     #$C1                            ; AD91 A9 C1                    ..
        rts                                     ; AD93 60                       `

; ----------------------------------------------------------------------------
; XXX how does this work?
move_down:
        lda     #$DA                            ; AD94 A9 DA                    ..
        clc                                     ; AD96 18                       .
        rts                                     ; AD97 60                       `

; ----------------------------------------------------------------------------
; ship not moving up or down XXX how does this work?
no_vert_move:
        lda     #$00                            ; AD98 A9 00                    ..
        sta     $E9                             ; AD9A 85 E9                    ..
        sta     $EA                             ; AD9C 85 EA                    ..
return_carry_set:
        sec                                     ; AD9E 38                       8
        rts                                     ; AD9F 60                       `

; ----------------------------------------------------------------------------
; used for accelerating/decelarating the ship
accel_table:
        .byte   $FA,$FB,$FC,$FD,$FE,$FF,$FF,$00 ; ADA0 FA FB FC FD FE FF FF 00  ........
        .byte   $01,$01,$02,$03,$04,$05,$06,$00 ; ADA8 01 01 02 03 04 05 06 00  ........
; ----------------------------------------------------------------------------
; result in A and Y. notice it's inverted.
read_joystick:
        lda     current_player                  ; ADB0 A5 F1                    ..
        cmp     #$02                            ; ADB2 C9 02                    ..
        beq     read_joystick_p2                ; ADB4 F0 09                    ..
        lda     PORTA                           ; ADB6 AD 00 D3                 ...
        and     #$0F                            ; ADB9 29 0F                    ).
        eor     #$0F                            ; ADBB 49 0F                    I.
        tay                                     ; ADBD A8                       .
        rts                                     ; ADBE 60                       `

; ----------------------------------------------------------------------------
read_joystick_p2:
        lda     PORTA                           ; ADBF AD 00 D3                 ...
        lsr     a                               ; ADC2 4A                       J
        lsr     a                               ; ADC3 4A                       J
        lsr     a                               ; ADC4 4A                       J
        lsr     a                               ; ADC5 4A                       J
        eor     #$0F                            ; ADC6 49 0F                    I.
        tay                                     ; ADC8 A8                       .
        rts                                     ; ADC9 60                       `

; ----------------------------------------------------------------------------
        lda     $11,x                           ; ADCA B5 11                    ..
        cmp     $1437,x                         ; ADCC DD 37 14                 .7.
        bcc     LADD6                           ; ADCF 90 05                    ..
        sta     $1437,x                         ; ADD1 9D 37 14                 .7.
        bcs     LADDE                           ; ADD4 B0 08                    ..
LADD6:  cmp     $1433,x                         ; ADD6 DD 33 14                 .3.
        bcs     LADDE                           ; ADD9 B0 03                    ..
        sta     $1433,x                         ; ADDB 9D 33 14                 .3.
LADDE:  lda     $1437,x                         ; ADDE BD 37 14                 .7.
        clc                                     ; ADE1 18                       .
        adc     $1433,x                         ; ADE2 7D 33 14                 }3.
        ror     a                               ; ADE5 6A                       j
        sta     $1435,x                         ; ADE6 9D 35 14                 .5.
        bit     $F2                             ; ADE9 24 F2                    $.
        bmi     LAE02                           ; ADEB 30 15                    0.
        clc                                     ; ADED 18                       .
        lda     $1435,x                         ; ADEE BD 35 14                 .5.
        adc     table_ae15,x                    ; ADF1 7D 15 AE                 }..
        sta     $EB                             ; ADF4 85 EB                    ..
        sec                                     ; ADF6 38                       8
        lda     $1435,x                         ; ADF7 BD 35 14                 .5.
        sbc     table_ae15,x                    ; ADFA FD 15 AE                 ...
        sta     $EC                             ; ADFD 85 EC                    ..
        jmp     LAE12                           ; ADFF 4C 12 AE                 L..

; ----------------------------------------------------------------------------
LAE02:  clc                                     ; AE02 18                       .
        lda     $1435,x                         ; AE03 BD 35 14                 .5.
        adc     #$10                            ; AE06 69 10                    i.
        sta     $EB                             ; AE08 85 EB                    ..
        sec                                     ; AE0A 38                       8
        lda     $1435,x                         ; AE0B BD 35 14                 .5.
        sbc     #$10                            ; AE0E E9 10                    ..
        sta     $EC                             ; AE10 85 EC                    ..
LAE12:  ldy     $11,x                           ; AE12 B4 11                    ..
        rts                                     ; AE14 60                       `

; ----------------------------------------------------------------------------
table_ae15:
        .byte   $3E,$20                         ; AE15 3E 20                    > 
; ----------------------------------------------------------------------------
LAE17:  lda     #$0A                            ; AE17 A9 0A                    ..
LAE19:  pha                                     ; AE19 48                       H
        jsr     get_random                      ; AE1A 20 F2 8C                  ..
        sta     $DD                             ; AE1D 85 DD                    ..
        lda     random_seed+1                   ; AE1F A5 C7                    ..
        and     #$01                            ; AE21 29 01                    ).
        sta     $DE                             ; AE23 85 DE                    ..
        clc                                     ; AE25 18                       .
        lda     $DD                             ; AE26 A5 DD                    ..
        adc     #$AB                            ; AE28 69 AB                    i.
        sta     tmp_ptr                         ; AE2A 85 E7                    ..
        lda     $DE                             ; AE2C A5 DE                    ..
        adc     #$05                            ; AE2E 69 05                    i.
        sta     tmp_ptr+1                       ; AE30 85 E8                    ..
        ldy     #$00                            ; AE32 A0 00                    ..
        lda     (tmp_ptr),y                     ; AE34 B1 E7                    ..
        clc                                     ; AE36 18                       .
        adc     #$08                            ; AE37 69 08                    i.
        sta     sprite_y                        ; AE39 85 DF                    ..
        lda     #$00                            ; AE3B A9 00                    ..
        sta     current_sprite                  ; AE3D 85 F9                    ..
        jsr     add_to_sprite_list              ; AE3F 20 A5 A4                  ..
        pla                                     ; AE42 68                       h
        sec                                     ; AE43 38                       8
        sbc     #$01                            ; AE44 E9 01                    ..
        bne     LAE19                           ; AE46 D0 D1                    ..
        rts                                     ; AE48 60                       `

; ----------------------------------------------------------------------------
; 3 bytes per entry: # bombers, # pods, # landers per wave
level_spawn_table:
        .byte   $00                             ; AE49 00                       .
lst_pods:
        .byte   $00                             ; AE4A 00                       .
lst_landers:
        .byte   $0F,$03,$01,$14,$04,$03,$14,$06 ; AE4B 0F 03 01 14 04 03 14 06  ........
        .byte   $04,$14                         ; AE53 04 14                    ..
; ----------------------------------------------------------------------------
; at level start, spawn initial set of enemies
level_initial_spawn:
        lda     level                           ; AE55 A5 9A                    ..
        asl     a                               ; AE57 0A                       .
        clc                                     ; AE58 18                       .
        adc     level                           ; AE59 65 9A                    e.
        cmp     #$09                            ; AE5B C9 09                    ..
        bcc     spawn_bombers                   ; AE5D 90 02                    ..
        lda     #$09                            ; AE5F A9 09                    ..
; not sure what's up with location $c6 here
spawn_bombers:
        tax                                     ; AE61 AA                       .
        lda     level_spawn_table,x             ; AE62 BD 49 AE                 .I.
        beq     spawn_pods                      ; AE65 F0 16                    ..
spb_loop:
        pha                                     ; AE67 48                       H
        jsr     get_spawn_pos                   ; AE68 20 0C 8D                  ..
        lda     random_seed                     ; AE6B A5 C6                    ..
        and     #$08                            ; AE6D 29 08                    ).
        clc                                     ; AE6F 18                       .
        adc     #$04                            ; AE70 69 04                    i.
        sta     current_sprite                  ; AE72 85 F9                    ..
        jsr     spawn_sprite                    ; AE74 20 ED AB                  ..
        pla                                     ; AE77 68                       h
        sec                                     ; AE78 38                       8
        sbc     #$01                            ; AE79 E9 01                    ..
        bne     spb_loop                        ; AE7B D0 EA                    ..
spawn_pods:
        lda     lst_pods,x                      ; AE7D BD 4A AE                 .J.
        beq     spawn_landers                   ; AE80 F0 11                    ..
spp_loop:
        pha                                     ; AE82 48                       H
        jsr     get_spawn_pos                   ; AE83 20 0C 8D                  ..
        lda     #$05                            ; AE86 A9 05                    ..
        sta     current_sprite                  ; AE88 85 F9                    ..
        jsr     spawn_sprite                    ; AE8A 20 ED AB                  ..
        pla                                     ; AE8D 68                       h
        sec                                     ; AE8E 38                       8
        sbc     #$01                            ; AE8F E9 01                    ..
        bne     spp_loop                        ; AE91 D0 EF                    ..
spawn_landers:
        lda     lst_landers,x                   ; AE93 BD 4B AE                 .K.
        sta     landers_to_spawn                ; AE96 85 9B                    ..
; also called from outside level_initial_spawn, for subsequent waves
spawn_lander_wave:
        lda     landers_to_spawn                ; AE98 A5 9B                    ..
        beq     lis_done                        ; AE9A F0 49                    .I
        jsr     play_materialize                ; AE9C 20 32 8E                  2.
        jsr     get_spawn_pos                   ; AE9F 20 0C 8D                  ..
        lda     #$01                            ; AEA2 A9 01                    ..
        sta     current_sprite                  ; AEA4 85 F9                    ..
        jsr     spawn_sprite                    ; AEA6 20 ED AB                  ..
        dec     landers_to_spawn                ; AEA9 C6 9B                    ..
        beq     lis_done                        ; AEAB F0 38                    .8
        jsr     get_spawn_pos                   ; AEAD 20 0C 8D                  ..
        lda     #$01                            ; AEB0 A9 01                    ..
        sta     current_sprite                  ; AEB2 85 F9                    ..
        jsr     spawn_sprite                    ; AEB4 20 ED AB                  ..
        dec     landers_to_spawn                ; AEB7 C6 9B                    ..
        beq     lis_done                        ; AEB9 F0 2A                    .*
        jsr     get_spawn_pos                   ; AEBB 20 0C 8D                  ..
        lda     #$01                            ; AEBE A9 01                    ..
        sta     current_sprite                  ; AEC0 85 F9                    ..
        jsr     spawn_sprite                    ; AEC2 20 ED AB                  ..
        dec     landers_to_spawn                ; AEC5 C6 9B                    ..
        beq     lis_done                        ; AEC7 F0 1C                    ..
        jsr     get_spawn_pos                   ; AEC9 20 0C 8D                  ..
        lda     #$01                            ; AECC A9 01                    ..
        sta     current_sprite                  ; AECE 85 F9                    ..
        jsr     spawn_sprite                    ; AED0 20 ED AB                  ..
        dec     landers_to_spawn                ; AED3 C6 9B                    ..
        beq     lis_done                        ; AED5 F0 0E                    ..
        jsr     get_spawn_pos                   ; AED7 20 0C 8D                  ..
        lda     #$01                            ; AEDA A9 01                    ..
        sta     current_sprite                  ; AEDC 85 F9                    ..
        jsr     spawn_sprite                    ; AEDE 20 ED AB                  ..
        dec     landers_to_spawn                ; AEE1 C6 9B                    ..
        beq     lis_done                        ; AEE3 F0 00                    ..
lis_done:
        rts                                     ; AEE5 60                       `

; ----------------------------------------------------------------------------
; 'spawn' not the right word. this does all the logic for humanoids (falling, hitting the ground)
spawn_humanoid:
        ldy     $98                             ; AEE6 A4 98                    ..
        inc     humanoid_count                  ; AEE8 E6 A1                    ..
        lda     current_sprite                  ; AEEA A5 F9                    ..
        beq     LAF55                           ; AEEC F0 67                    .g
        cmp     #$10                            ; AEEE C9 10                    ..
        beq     humanoid_falling                ; AEF0 F0 7C                    .|
        bcc     humanoid_abducted               ; AEF2 90 6B                    .k
; player carrying a humanoid
humanoid_carrying:
        clc                                     ; AEF4 18                       .
        lda     $91                             ; AEF5 A5 91                    ..
        adc     #$02                            ; AEF7 69 02                    i.
        sta     $DD                             ; AEF9 85 DD                    ..
        lda     $92                             ; AEFB A5 92                    ..
        adc     #$00                            ; AEFD 69 00                    i.
        sta     $DE                             ; AEFF 85 DE                    ..
        lda     ship_y_pos                      ; AF01 A5 C4                    ..
        clc                                     ; AF03 18                       .
        adc     #$0A                            ; AF04 69 0A                    i.
        sta     sprite_y                        ; AF06 85 DF                    ..
        clc                                     ; AF08 18                       .
        lda     $DD                             ; AF09 A5 DD                    ..
        adc     #$AB                            ; AF0B 69 AB                    i.
        sta     tmp_ptr                         ; AF0D 85 E7                    ..
        lda     $DE                             ; AF0F A5 DE                    ..
        adc     #$05                            ; AF11 69 05                    i.
        sta     tmp_ptr+1                       ; AF13 85 E8                    ..
        ldy     #$00                            ; AF15 A0 00                    ..
        lda     (tmp_ptr),y                     ; AF17 B1 E7                    ..
        cmp     sprite_y                        ; AF19 C5 DF                    ..
        bcs     LAF4E                           ; AF1B B0 31                    .1
        lda     #$0C                            ; AF1D A9 0C                    ..
        jsr     add_points                      ; AF1F 20 B2 A7                  ..
        lda     #$00                            ; AF22 A9 00                    ..
        sta     current_sprite                  ; AF24 85 F9                    ..
        clc                                     ; AF26 18                       .
        lda     $98                             ; AF27 A5 98                    ..
        lsr     a                               ; AF29 4A                       J
        adc     $DD                             ; AF2A 65 DD                    e.
        sta     $DD                             ; AF2C 85 DD                    ..
        lda     $DE                             ; AF2E A5 DE                    ..
        adc     #$00                            ; AF30 69 00                    i.
        sta     $DE                             ; AF32 85 DE                    ..
        clc                                     ; AF34 18                       .
        lda     $98                             ; AF35 A5 98                    ..
        lsr     a                               ; AF37 4A                       J
        adc     tmp_ptr                         ; AF38 65 E7                    e.
        sta     tmp_ptr                         ; AF3A 85 E7                    ..
        lda     tmp_ptr+1                       ; AF3C A5 E8                    ..
        adc     #$00                            ; AF3E 69 00                    i.
        sta     tmp_ptr+1                       ; AF40 85 E8                    ..
        ldy     #$00                            ; AF42 A0 00                    ..
        lda     (tmp_ptr),y                     ; AF44 B1 E7                    ..
        clc                                     ; AF46 18                       .
        adc     #$08                            ; AF47 69 08                    i.
        sta     sprite_y                        ; AF49 85 DF                    ..
        jsr     play_rescued                    ; AF4B 20 16 8E                  ..
LAF4E:  lda     #$00                            ; AF4E A9 00                    ..
        sta     $88                             ; AF50 85 88                    ..
        jmp     LA5B2                           ; AF52 4C B2 A5                 L..

; ----------------------------------------------------------------------------
LAF55:  jsr     LB047                           ; AF55 20 47 B0                  G.
        lda     #$00                            ; AF58 A9 00                    ..
        sta     $88                             ; AF5A 85 88                    ..
        jmp     LA5B2                           ; AF5C 4C B2 A5                 L..

; ----------------------------------------------------------------------------
; lander carrying a humanoid
humanoid_abducted:
        sec                                     ; AF5F 38                       8
        lda     sprite_y                        ; AF60 A5 DF                    ..
        sbc     sprite_list+128,y               ; AF62 F9 6B 0B                 .k.
        sta     sprite_y                        ; AF65 85 DF                    ..
        lda     #$00                            ; AF67 A9 00                    ..
        sta     $88                             ; AF69 85 88                    ..
        jmp     LA5B2                           ; AF6B 4C B2 A5                 L..

; ----------------------------------------------------------------------------
; called repeatedly while a humanoid is falling
humanoid_falling:
        ldx     $98                             ; AF6E A6 98                    ..
        inc     sprite_list+128,x               ; AF70 FE 6B 0B                 .k.
        lda     sprite_list+128,x               ; AF73 BD 6B 0B                 .k.
        lsr     a                               ; AF76 4A                       J
        lsr     a                               ; AF77 4A                       J
        lsr     a                               ; AF78 4A                       J
        lsr     a                               ; AF79 4A                       J
        lsr     a                               ; AF7A 4A                       J
        clc                                     ; AF7B 18                       .
        adc     #$01                            ; AF7C 69 01                    i.
        clc                                     ; AF7E 18                       .
        adc     sprite_y                        ; AF7F 65 DF                    e.
        sta     sprite_y                        ; AF81 85 DF                    ..
        sec                                     ; AF83 38                       8
        lda     ship_y_pos                      ; AF84 A5 C4                    ..
        sbc     sprite_y                        ; AF86 E5 DF                    ..
        bcs     LAF8E                           ; AF88 B0 04                    ..
        eor     #$FF                            ; AF8A 49 FF                    I.
        adc     #$01                            ; AF8C 69 01                    i.
LAF8E:  cmp     #$0A                            ; AF8E C9 0A                    ..
        bcs     LAFD4                           ; AF90 B0 42                    .B
        sec                                     ; AF92 38                       8
        lda     $DD                             ; AF93 A5 DD                    ..
        sbc     $89                             ; AF95 E5 89                    ..
        sta     sprite_x                        ; AF97 85 E3                    ..
        lda     $DE                             ; AF99 A5 DE                    ..
        sbc     $8A                             ; AF9B E5 8A                    ..
        sta     $E4                             ; AF9D 85 E4                    ..
        bcs     LAFAE                           ; AF9F B0 0D                    ..
        clc                                     ; AFA1 18                       .
        lda     sprite_x                        ; AFA2 A5 E3                    ..
        adc     #$80                            ; AFA4 69 80                    i.
        sta     sprite_x                        ; AFA6 85 E3                    ..
        lda     $E4                             ; AFA8 A5 E4                    ..
        adc     #$02                            ; AFAA 69 02                    i.
        sta     $E4                             ; AFAC 85 E4                    ..
LAFAE:  lda     $E4                             ; AFAE A5 E4                    ..
        bne     LAFD4                           ; AFB0 D0 22                    ."
        lda     sprite_x                        ; AFB2 A5 E3                    ..
        cmp     #$A0                            ; AFB4 C9 A0                    ..
        bcs     LAFD4                           ; AFB6 B0 1C                    ..
        sec                                     ; AFB8 38                       8
        sbc     ship_x_pos                      ; AFB9 E5 C3                    ..
        bcs     LAFC1                           ; AFBB B0 04                    ..
        eor     #$FF                            ; AFBD 49 FF                    I.
        adc     #$01                            ; AFBF 69 01                    i.
LAFC1:  cmp     #$10                            ; AFC1 C9 10                    ..
        bcs     LAFD4                           ; AFC3 B0 0F                    ..
        lda     #$0C                            ; AFC5 A9 0C                    ..
        jsr     add_points                      ; AFC7 20 B2 A7                  ..
        lda     #$18                            ; AFCA A9 18                    ..
        sta     current_sprite                  ; AFCC 85 F9                    ..
        jsr     play_rescued                    ; AFCE 20 16 8E                  ..
        jmp     humanoid_carrying               ; AFD1 4C F4 AE                 L..

; ----------------------------------------------------------------------------
LAFD4:  clc                                     ; AFD4 18                       .
        lda     $DD                             ; AFD5 A5 DD                    ..
        adc     #$AB                            ; AFD7 69 AB                    i.
        sta     tmp_ptr                         ; AFD9 85 E7                    ..
        lda     $DE                             ; AFDB A5 DE                    ..
        adc     #$05                            ; AFDD 69 05                    i.
        sta     tmp_ptr+1                       ; AFDF 85 E8                    ..
        ldy     #$00                            ; AFE1 A0 00                    ..
        lda     (tmp_ptr),y                     ; AFE3 B1 E7                    ..
        cmp     sprite_y                        ; AFE5 C5 DF                    ..
        bcs     LB040                           ; AFE7 B0 57                    .W
        lda     sprite_list+128,x               ; AFE9 BD 6B 0B                 .k.
        cmp     #$28                            ; AFEC C9 28                    .(
        bcs     LAFFF                           ; AFEE B0 0F                    ..
        lda     #$04                            ; AFF0 A9 04                    ..
        jsr     add_points                      ; AFF2 20 B2 A7                  ..
        lda     #$00                            ; AFF5 A9 00                    ..
        sta     current_sprite                  ; AFF7 85 F9                    ..
        jsr     play_rescued                    ; AFF9 20 16 8E                  ..
        jmp     LB040                           ; AFFC 4C 40 B0                 L@.

; ----------------------------------------------------------------------------
LAFFF:  sec                                     ; AFFF 38                       8
        lda     $DD                             ; B000 A5 DD                    ..
        sbc     $89                             ; B002 E5 89                    ..
        sta     sprite_x                        ; B004 85 E3                    ..
        lda     $DE                             ; B006 A5 DE                    ..
        sbc     $8A                             ; B008 E5 8A                    ..
        sta     $E4                             ; B00A 85 E4                    ..
        bcs     LB01A                           ; B00C B0 0C                    ..
        lda     sprite_x                        ; B00E A5 E3                    ..
        adc     #$80                            ; B010 69 80                    i.
        sta     sprite_x                        ; B012 85 E3                    ..
        lda     $E4                             ; B014 A5 E4                    ..
        adc     #$02                            ; B016 69 02                    i.
        sta     $E4                             ; B018 85 E4                    ..
LB01A:  lda     $E4                             ; B01A A5 E4                    ..
        bne     LB033                           ; B01C D0 15                    ..
        lda     sprite_x                        ; B01E A5 E3                    ..
        cmp     #$A0                            ; B020 C9 A0                    ..
        bcs     LB033                           ; B022 B0 0F                    ..
        lda     sprite_x                        ; B024 A5 E3                    ..
        sta     $C9                             ; B026 85 C9                    ..
        lda     sprite_y                        ; B028 A5 DF                    ..
        sta     $CA                             ; B02A 85 CA                    ..
        lda     #$01                            ; B02C A9 01                    ..
        sta     $CB                             ; B02E 85 CB                    ..
        jsr     start_enemy_explosion           ; B030 20 E7 9B                  ..
LB033:  jsr     play_human_died                 ; B033 20 24 8E                  $.
        ldy     $98                             ; B036 A4 98                    ..
        lda     #$00                            ; B038 A9 00                    ..
        sta     sprite_list,y                   ; B03A 99 EB 0A                 ...
        jmp     LA4DD                           ; B03D 4C DD A4                 L..

; ----------------------------------------------------------------------------
LB040:  lda     #$00                            ; B040 A9 00                    ..
        sta     $88                             ; B042 85 88                    ..
        jmp     LA5B2                           ; B044 4C B2 A5                 L..

; ----------------------------------------------------------------------------
LB047:  lda     animation_counter               ; B047 A5 85                    ..
        and     #$07                            ; B049 29 07                    ).
        bne     LB08D                           ; B04B D0 40                    .@
        lda     $98                             ; B04D A5 98                    ..
        and     #$04                            ; B04F 29 04                    ).
        bne     LB05C                           ; B051 D0 09                    ..
        inc     $DD                             ; B053 E6 DD                    ..
        bne     LB077                           ; B055 D0 20                    . 
        inc     $DE                             ; B057 E6 DE                    ..
        jmp     LB077                           ; B059 4C 77 B0                 Lw.

; ----------------------------------------------------------------------------
LB05C:  sec                                     ; B05C 38                       8
        lda     $DD                             ; B05D A5 DD                    ..
        sbc     #$01                            ; B05F E9 01                    ..
        sta     $DD                             ; B061 85 DD                    ..
        lda     $DE                             ; B063 A5 DE                    ..
        sbc     #$00                            ; B065 E9 00                    ..
        sta     $DE                             ; B067 85 DE                    ..
        bcs     LB077                           ; B069 B0 0C                    ..
        lda     $DD                             ; B06B A5 DD                    ..
        adc     #$80                            ; B06D 69 80                    i.
        sta     $DD                             ; B06F 85 DD                    ..
        lda     $DE                             ; B071 A5 DE                    ..
        adc     #$02                            ; B073 69 02                    i.
        sta     $DE                             ; B075 85 DE                    ..
LB077:  clc                                     ; B077 18                       .
        lda     $DD                             ; B078 A5 DD                    ..
        adc     #$AB                            ; B07A 69 AB                    i.
        sta     tmp_ptr                         ; B07C 85 E7                    ..
        lda     $DE                             ; B07E A5 DE                    ..
        adc     #$05                            ; B080 69 05                    i.
        sta     tmp_ptr+1                       ; B082 85 E8                    ..
        ldy     #$00                            ; B084 A0 00                    ..
        lda     (tmp_ptr),y                     ; B086 B1 E7                    ..
        clc                                     ; B088 18                       .
        adc     #$08                            ; B089 69 08                    i.
        sta     sprite_y                        ; B08B 85 DF                    ..
LB08D:  rts                                     ; B08D 60                       `

; ----------------------------------------------------------------------------
spawn_lander:
        lda     #$01                            ; B08E A9 01                    ..
        sta     $B9                             ; B090 85 B9                    ..
        lda     level                           ; B092 A5 9A                    ..
        lsr     a                               ; B094 4A                       J
        lsr     a                               ; B095 4A                       J
        clc                                     ; B096 18                       .
        adc     $B9                             ; B097 65 B9                    e.
        sta     $B9                             ; B099 85 B9                    ..
        lda     $98                             ; B09B A5 98                    ..
        and     #$08                            ; B09D 29 08                    ).
        bne     LB0A3                           ; B09F D0 02                    ..
        inc     $B9                             ; B0A1 E6 B9                    ..
LB0A3:  lda     $B9                             ; B0A3 A5 B9                    ..
        cmp     #$04                            ; B0A5 C9 04                    ..
        bcc     LB0AD                           ; B0A7 90 04                    ..
        lda     #$03                            ; B0A9 A9 03                    ..
        sta     $B9                             ; B0AB 85 B9                    ..
LB0AD:  inc     enemy_count                     ; B0AD E6 9C                    ..
        lda     planet_dead_flag                ; B0AF A5 A0                    ..
        bpl     LB0B9                           ; B0B1 10 06                    ..
        jsr     LB2DE                           ; B0B3 20 DE B2                  ..
        jmp     spawn_mutant                    ; B0B6 4C F4 B2                 L..

; ----------------------------------------------------------------------------
LB0B9:  lda     current_sprite                  ; B0B9 A5 F9                    ..
        cmp     #$09                            ; B0BB C9 09                    ..
        beq     LB0DF                           ; B0BD F0 20                    . 
        bcc     LB0E2                           ; B0BF 90 21                    .!
        lda     #$03                            ; B0C1 A9 03                    ..
        sta     $94                             ; B0C3 85 94                    ..
        lda     animation_counter               ; B0C5 A5 85                    ..
        and     enemy_firing_freq               ; B0C7 25 BB                    %.
        bne     LB0CE                           ; B0C9 D0 03                    ..
        jsr     L9A9C                           ; B0CB 20 9C 9A                  ..
LB0CE:  sec                                     ; B0CE 38                       8
        lda     sprite_y                        ; B0CF A5 DF                    ..
        sbc     $B9                             ; B0D1 E5 B9                    ..
        sta     sprite_y                        ; B0D3 85 DF                    ..
        cmp     #$20                            ; B0D5 C9 20                    . 
        bcs     LB0DC                           ; B0D7 B0 03                    ..
        jsr     LB251                           ; B0D9 20 51 B2                  Q.
LB0DC:  jmp     LB166                           ; B0DC 4C 66 B1                 Lf.

; ----------------------------------------------------------------------------
LB0DF:  jmp     LB18F                           ; B0DF 4C 8F B1                 L..

; ----------------------------------------------------------------------------
LB0E2:  lda     animation_counter               ; B0E2 A5 85                    ..
        and     #$01                            ; B0E4 29 01                    ).
        bne     LB10D                           ; B0E6 D0 25                    .%
        lda     $98                             ; B0E8 A5 98                    ..
        lsr     a                               ; B0EA 4A                       J
        lsr     a                               ; B0EB 4A                       J
        and     #$04                            ; B0EC 29 04                    ).
        bne     LB100                           ; B0EE D0 10                    ..
        clc                                     ; B0F0 18                       .
        lda     $DD                             ; B0F1 A5 DD                    ..
        adc     $B9                             ; B0F3 65 B9                    e.
        sta     $DD                             ; B0F5 85 DD                    ..
        lda     $DE                             ; B0F7 A5 DE                    ..
        adc     #$00                            ; B0F9 69 00                    i.
        sta     $DE                             ; B0FB 85 DE                    ..
        jmp     LB10D                           ; B0FD 4C 0D B1                 L..

; ----------------------------------------------------------------------------
LB100:  sec                                     ; B100 38                       8
        lda     $DD                             ; B101 A5 DD                    ..
        sbc     $B9                             ; B103 E5 B9                    ..
        sta     $DD                             ; B105 85 DD                    ..
        lda     $DE                             ; B107 A5 DE                    ..
        sbc     #$00                            ; B109 E9 00                    ..
        sta     $DE                             ; B10B 85 DE                    ..
LB10D:  lda     $B9                             ; B10D A5 B9                    ..
        lsr     a                               ; B10F 4A                       J
        clc                                     ; B110 18                       .
        adc     #$01                            ; B111 69 01                    i.
        adc     sprite_y                        ; B113 65 DF                    e.
        sta     sprite_y                        ; B115 85 DF                    ..
        clc                                     ; B117 18                       .
        lda     #$AB                            ; B118 A9 AB                    ..
        adc     $DD                             ; B11A 65 DD                    e.
        sta     tmp_ptr                         ; B11C 85 E7                    ..
        lda     #$05                            ; B11E A9 05                    ..
        adc     $DE                             ; B120 65 DE                    e.
        sta     tmp_ptr+1                       ; B122 85 E8                    ..
        ldy     #$00                            ; B124 A0 00                    ..
        lda     (tmp_ptr),y                     ; B126 B1 E7                    ..
        sec                                     ; B128 38                       8
        sbc     #$1E                            ; B129 E9 1E                    ..
        sta     sprite_x                        ; B12B 85 E3                    ..
        lda     sprite_y                        ; B12D A5 DF                    ..
        cmp     sprite_x                        ; B12F C5 E3                    ..
        bcc     LB166                           ; B131 90 33                    .3
        lda     $B9                             ; B133 A5 B9                    ..
        lsr     a                               ; B135 4A                       J
        clc                                     ; B136 18                       .
        adc     #$01                            ; B137 69 01                    i.
        sta     sprite_x                        ; B139 85 E3                    ..
        sec                                     ; B13B 38                       8
        lda     sprite_y                        ; B13C A5 DF                    ..
        sbc     sprite_x                        ; B13E E5 E3                    ..
        sta     sprite_y                        ; B140 85 DF                    ..
        dec     sprite_y                        ; B142 C6 DF                    ..
        lda     current_sprite                  ; B144 A5 F9                    ..
        cmp     #$09                            ; B146 C9 09                    ..
        beq     LB166                           ; B148 F0 1C                    ..
        lda     #$09                            ; B14A A9 09                    ..
        sta     current_sprite                  ; B14C 85 F9                    ..
        jsr     LB22C                           ; B14E 20 2C B2                  ,.
        bcc     LB166                           ; B151 90 13                    ..
        lda     #$01                            ; B153 A9 01                    ..
        sta     current_sprite                  ; B155 85 F9                    ..
        lda     #$03                            ; B157 A9 03                    ..
        sta     $94                             ; B159 85 94                    ..
        lda     animation_counter               ; B15B A5 85                    ..
        adc     #$01                            ; B15D 69 01                    i.
        and     #$03                            ; B15F 29 03                    ).
        bne     LB166                           ; B161 D0 03                    ..
        jsr     L9A9C                           ; B163 20 9C 9A                  ..
LB166:  lda     animation_counter               ; B166 A5 85                    ..
        and     #$02                            ; B168 29 02                    ).
        lsr     a                               ; B16A 4A                       J
        clc                                     ; B16B 18                       .
        adc     #$01                            ; B16C 69 01                    i.
        sta     $88                             ; B16E 85 88                    ..
        lda     animation_counter               ; B170 A5 85                    ..
        adc     $98                             ; B172 65 98                    e.
        and     #$3F                            ; B174 29 3F                    )?
        bne     LB18C                           ; B176 D0 14                    ..
        lda     ship_delta                      ; B178 A5 D5                    ..
        bpl     LB181                           ; B17A 10 05                    ..
        eor     #$FF                            ; B17C 49 FF                    I.
        clc                                     ; B17E 18                       .
        adc     #$01                            ; B17F 69 01                    i.
LB181:  cmp     #$03                            ; B181 C9 03                    ..
        bcc     LB18C                           ; B183 90 07                    ..
        lda     #$03                            ; B185 A9 03                    ..
        sta     $94                             ; B187 85 94                    ..
        jsr     L9A9C                           ; B189 20 9C 9A                  ..
LB18C:  jmp     LA5B2                           ; B18C 4C B2 A5                 L..

; ----------------------------------------------------------------------------
LB18F:  lda     sprite_list+128,y               ; B18F B9 6B 0B                 .k.
        tax                                     ; B192 AA                       .
        lda     sprite_list,x                   ; B193 BD EB 0A                 ...
        beq     LB19D                           ; B196 F0 05                    ..
        lda     sprite_list+3,x                 ; B198 BD EE 0A                 ...
        beq     LB1A9                           ; B19B F0 0C                    ..
LB19D:  jsr     LB22C                           ; B19D 20 2C B2                  ,.
        bcc     LB1A6                           ; B1A0 90 04                    ..
        lda     #$01                            ; B1A2 A9 01                    ..
        sta     current_sprite                  ; B1A4 85 F9                    ..
LB1A6:  jmp     LB166                           ; B1A6 4C 66 B1                 Lf.

; ----------------------------------------------------------------------------
LB1A9:  lda     $DD                             ; B1A9 A5 DD                    ..
        cmp     sprite_list+1,x                 ; B1AB DD EC 0A                 ...
        lda     $DE                             ; B1AE A5 DE                    ..
        sbc     sprite_list+2,x                 ; B1B0 FD ED 0A                 ...
        bcs     LB1C3                           ; B1B3 B0 0E                    ..
        clc                                     ; B1B5 18                       .
        lda     $DD                             ; B1B6 A5 DD                    ..
        adc     $B9                             ; B1B8 65 B9                    e.
        sta     $DD                             ; B1BA 85 DD                    ..
        bcc     LB1C0                           ; B1BC 90 02                    ..
        inc     $DE                             ; B1BE E6 DE                    ..
LB1C0:  jmp     LB10D                           ; B1C0 4C 0D B1                 L..

; ----------------------------------------------------------------------------
LB1C3:  sec                                     ; B1C3 38                       8
        lda     $DD                             ; B1C4 A5 DD                    ..
        sbc     sprite_list+1,x                 ; B1C6 FD EC 0A                 ...
        sta     sprite_x                        ; B1C9 85 E3                    ..
        lda     $DE                             ; B1CB A5 DE                    ..
        sbc     sprite_list+2,x                 ; B1CD FD ED 0A                 ...
        sta     $E4                             ; B1D0 85 E4                    ..
        bcs     LB1E0                           ; B1D2 B0 0C                    ..
        lda     sprite_x                        ; B1D4 A5 E3                    ..
        adc     #$80                            ; B1D6 69 80                    i.
        sta     sprite_x                        ; B1D8 85 E3                    ..
        lda     $E4                             ; B1DA A5 E4                    ..
        adc     #$02                            ; B1DC 69 02                    i.
        sta     $E4                             ; B1DE 85 E4                    ..
LB1E0:  lda     $E4                             ; B1E0 A5 E4                    ..
        bne     LB21C                           ; B1E2 D0 38                    .8
        lda     sprite_x                        ; B1E4 A5 E3                    ..
        cmp     #$03                            ; B1E6 C9 03                    ..
        bcs     LB21C                           ; B1E8 B0 32                    .2
        lda     sprite_list,x                   ; B1EA BD EB 0A                 ...
        sec                                     ; B1ED 38                       8
        sbc     #$0C                            ; B1EE E9 0C                    ..
        cmp     sprite_y                        ; B1F0 C5 DF                    ..
        bcs     LB208                           ; B1F2 B0 14                    ..
        lda     #$11                            ; B1F4 A9 11                    ..
        sta     current_sprite                  ; B1F6 85 F9                    ..
        lda     #$08                            ; B1F8 A9 08                    ..
        sta     sprite_list+3,x                 ; B1FA 9D EE 0A                 ...
        lda     $B9                             ; B1FD A5 B9                    ..
        sta     sprite_list+128,x               ; B1FF 9D 6B 0B                 .k.
        jsr     play_distress                   ; B202 20 40 8E                  @.
        jmp     LB166                           ; B205 4C 66 B1                 Lf.

; ----------------------------------------------------------------------------
LB208:  inc     sprite_y                        ; B208 E6 DF                    ..
        lda     #$03                            ; B20A A9 03                    ..
        sta     $94                             ; B20C 85 94                    ..
        lda     animation_counter               ; B20E A5 85                    ..
        adc     $98                             ; B210 65 98                    e.
        and     enemy_firing_freq               ; B212 25 BB                    %.
        bne     LB219                           ; B214 D0 03                    ..
        jsr     L9A9C                           ; B216 20 9C 9A                  ..
LB219:  jmp     LB166                           ; B219 4C 66 B1                 Lf.

; ----------------------------------------------------------------------------
LB21C:  sec                                     ; B21C 38                       8
        lda     $DD                             ; B21D A5 DD                    ..
        sbc     $B9                             ; B21F E5 B9                    ..
        sta     $DD                             ; B221 85 DD                    ..
        lda     $DE                             ; B223 A5 DE                    ..
        sbc     #$00                            ; B225 E9 00                    ..
        sta     $DE                             ; B227 85 DE                    ..
        jmp     LB10D                           ; B229 4C 0D B1                 L..

; ----------------------------------------------------------------------------
LB22C:  jsr     get_random                      ; B22C 20 F2 8C                  ..
        clc                                     ; B22F 18                       .
        adc     #$01                            ; B230 69 01                    i.
        and     #$0F                            ; B232 29 0F                    ).
        asl     a                               ; B234 0A                       .
        asl     a                               ; B235 0A                       .
        tax                                     ; B236 AA                       .
        lda     sprite_list+3,x                 ; B237 BD EE 0A                 ...
        beq     LB23E                           ; B23A F0 02                    ..
LB23C:  sec                                     ; B23C 38                       8
        rts                                     ; B23D 60                       `

; ----------------------------------------------------------------------------
LB23E:  lda     sprite_list,x                   ; B23E BD EB 0A                 ...
        beq     LB23C                           ; B241 F0 F9                    ..
        txa                                     ; B243 8A                       .
        ldy     $98                             ; B244 A4 98                    ..
        sta     sprite_list+128,y               ; B246 99 6B 0B                 .k.
        clc                                     ; B249 18                       .
        rts                                     ; B24A 60                       `

; ----------------------------------------------------------------------------
        rts                                     ; B24B 60                       `

; ----------------------------------------------------------------------------
LB24C:  lda     #$01                            ; B24C A9 01                    ..
        sta     current_sprite                  ; B24E 85 F9                    ..
        rts                                     ; B250 60                       `

; ----------------------------------------------------------------------------
LB251:  ldy     $98                             ; B251 A4 98                    ..
        lda     sprite_list+128,y               ; B253 B9 6B 0B                 .k.
        tax                                     ; B256 AA                       .
        lda     sprite_list,x                   ; B257 BD EB 0A                 ...
        beq     LB24C                           ; B25A F0 F0                    ..
        lda     sprite_list+3,x                 ; B25C BD EE 0A                 ...
        cmp     #$08                            ; B25F C9 08                    ..
        bne     LB24C                           ; B261 D0 E9                    ..
        lda     sprite_list,x                   ; B263 BD EB 0A                 ...
        sta     sprite_y                        ; B266 85 DF                    ..
        lda     #$00                            ; B268 A9 00                    ..
        sta     sprite_list,x                   ; B26A 9D EB 0A                 ...
        lda     sprite_list+1,x                 ; B26D BD EC 0A                 ...
        sta     $DD                             ; B270 85 DD                    ..
        lda     sprite_list+2,x                 ; B272 BD ED 0A                 ...
        sta     $DE                             ; B275 85 DE                    ..
        lda     $8B                             ; B277 A5 8B                    ..
        pha                                     ; B279 48                       H
        lda     $8C                             ; B27A A5 8C                    ..
        pha                                     ; B27C 48                       H
        lda     $8F                             ; B27D A5 8F                    ..
        pha                                     ; B27F 48                       H
        lda     $90                             ; B280 A5 90                    ..
        pha                                     ; B282 48                       H
        cpx     $98                             ; B283 E4 98                    ..
        bcc     LB297                           ; B285 90 10                    ..
        lda     $89                             ; B287 A5 89                    ..
        sta     $8B                             ; B289 85 8B                    ..
        lda     $8A                             ; B28B A5 8A                    ..
        sta     $8C                             ; B28D 85 8C                    ..
        lda     $8D                             ; B28F A5 8D                    ..
        sta     $8F                             ; B291 85 8F                    ..
        lda     $8E                             ; B293 A5 8E                    ..
        sta     $90                             ; B295 85 90                    ..
LB297:  jsr     erase_scanner_sprite            ; B297 20 2D A1                  -.
        jsr     erase_sprite_XXX                ; B29A 20 86 A7                  ..
        pla                                     ; B29D 68                       h
        sta     $90                             ; B29E 85 90                    ..
        pla                                     ; B2A0 68                       h
        sta     $8F                             ; B2A1 85 8F                    ..
        pla                                     ; B2A3 68                       h
        sta     $8C                             ; B2A4 85 8C                    ..
        pla                                     ; B2A6 68                       h
        sta     $8B                             ; B2A7 85 8B                    ..
        sec                                     ; B2A9 38                       8
        lda     $DD                             ; B2AA A5 DD                    ..
        sbc     $8B                             ; B2AC E5 8B                    ..
        sta     sprite_x                        ; B2AE 85 E3                    ..
        lda     $DE                             ; B2B0 A5 DE                    ..
        sbc     $8C                             ; B2B2 E5 8C                    ..
        sta     $E4                             ; B2B4 85 E4                    ..
        bcs     LB2C4                           ; B2B6 B0 0C                    ..
        lda     sprite_x                        ; B2B8 A5 E3                    ..
        adc     #$80                            ; B2BA 69 80                    i.
        sta     sprite_x                        ; B2BC 85 E3                    ..
        lda     $E4                             ; B2BE A5 E4                    ..
        adc     #$02                            ; B2C0 69 02                    i.
        sta     $E4                             ; B2C2 85 E4                    ..
LB2C4:  lda     $E4                             ; B2C4 A5 E4                    ..
        bne     LB2DB                           ; B2C6 D0 13                    ..
        lda     sprite_x                        ; B2C8 A5 E3                    ..
        cmp     #$A0                            ; B2CA C9 A0                    ..
        bcs     LB2DB                           ; B2CC B0 0D                    ..
        sta     $C9                             ; B2CE 85 C9                    ..
        lda     sprite_y                        ; B2D0 A5 DF                    ..
        sta     $CA                             ; B2D2 85 CA                    ..
        lda     #$01                            ; B2D4 A9 01                    ..
        sta     $CB                             ; B2D6 85 CB                    ..
        jsr     start_enemy_explosion           ; B2D8 20 E7 9B                  ..
LB2DB:  jsr     play_human_died                 ; B2DB 20 24 8E                  $.
LB2DE:  ldy     $98                             ; B2DE A4 98                    ..
        lda     sprite_list,y                   ; B2E0 B9 EB 0A                 ...
        sta     sprite_y                        ; B2E3 85 DF                    ..
        lda     sprite_list+1,y                 ; B2E5 B9 EC 0A                 ...
        sta     $DD                             ; B2E8 85 DD                    ..
        lda     sprite_list+2,y                 ; B2EA B9 ED 0A                 ...
        sta     $DE                             ; B2ED 85 DE                    ..
        lda     #$02                            ; B2EF A9 02                    ..
        sta     current_sprite                  ; B2F1 85 F9                    ..
        rts                                     ; B2F3 60                       `

; ----------------------------------------------------------------------------
spawn_mutant:
        inc     enemy_count                     ; B2F4 E6 9C                    ..
        lda     $91                             ; B2F6 A5 91                    ..
        cmp     $DD                             ; B2F8 C5 DD                    ..
        lda     $92                             ; B2FA A5 92                    ..
        sbc     $DE                             ; B2FC E5 DE                    ..
        bcs     LB319                           ; B2FE B0 19                    ..
        lda     random_seed                     ; B300 A5 C6                    ..
        and     #$03                            ; B302 29 03                    ).
        clc                                     ; B304 18                       .
        adc     #$02                            ; B305 69 02                    i.
        sta     $E5                             ; B307 85 E5                    ..
        sec                                     ; B309 38                       8
        lda     $DD                             ; B30A A5 DD                    ..
        sbc     $E5                             ; B30C E5 E5                    ..
        sta     $DD                             ; B30E 85 DD                    ..
        lda     $DE                             ; B310 A5 DE                    ..
        sbc     #$00                            ; B312 E9 00                    ..
        sta     $DE                             ; B314 85 DE                    ..
        jmp     LB32A                           ; B316 4C 2A B3                 L*.

; ----------------------------------------------------------------------------
LB319:  clc                                     ; B319 18                       .
        lda     random_seed                     ; B31A A5 C6                    ..
        and     #$03                            ; B31C 29 03                    ).
        adc     #$02                            ; B31E 69 02                    i.
        adc     $DD                             ; B320 65 DD                    e.
        sta     $DD                             ; B322 85 DD                    ..
        lda     $DE                             ; B324 A5 DE                    ..
        adc     #$00                            ; B326 69 00                    i.
        sta     $DE                             ; B328 85 DE                    ..
LB32A:  sec                                     ; B32A 38                       8
        lda     $DD                             ; B32B A5 DD                    ..
        sbc     $89                             ; B32D E5 89                    ..
        sta     sprite_x                        ; B32F 85 E3                    ..
        lda     $DE                             ; B331 A5 DE                    ..
        sbc     $8A                             ; B333 E5 8A                    ..
        sta     $E4                             ; B335 85 E4                    ..
        bcs     LB345                           ; B337 B0 0C                    ..
        lda     sprite_x                        ; B339 A5 E3                    ..
        adc     #$80                            ; B33B 69 80                    i.
        sta     sprite_x                        ; B33D 85 E3                    ..
        lda     $E4                             ; B33F A5 E4                    ..
        adc     #$02                            ; B341 69 02                    i.
        sta     $E4                             ; B343 85 E4                    ..
LB345:  lda     $E4                             ; B345 A5 E4                    ..
        bne     LB35E                           ; B347 D0 15                    ..
        lda     sprite_x                        ; B349 A5 E3                    ..
        cmp     #$A0                            ; B34B C9 A0                    ..
        bcs     LB35E                           ; B34D B0 0F                    ..
        sec                                     ; B34F 38                       8
        lda     sprite_x                        ; B350 A5 E3                    ..
        sbc     ship_x_pos                      ; B352 E5 C3                    ..
        bcs     LB35A                           ; B354 B0 04                    ..
        eor     #$FF                            ; B356 49 FF                    I.
        adc     #$01                            ; B358 69 01                    i.
LB35A:  cmp     #$20                            ; B35A C9 20                    . 
        bcc     LB39D                           ; B35C 90 3F                    .?
LB35E:  lda     ship_y_pos                      ; B35E A5 C4                    ..
        clc                                     ; B360 18                       .
        adc     #$40                            ; B361 69 40                    i@
        cmp     #$B0                            ; B363 C9 B0                    ..
        bcc     LB36D                           ; B365 90 06                    ..
        sec                                     ; B367 38                       8
        sbc     #$B0                            ; B368 E9 B0                    ..
        clc                                     ; B36A 18                       .
        adc     #$20                            ; B36B 69 20                    i 
LB36D:  cmp     sprite_y                        ; B36D C5 DF                    ..
        bcs     LB386                           ; B36F B0 15                    ..
        lda     random_seed                     ; B371 A5 C6                    ..
        and     #$03                            ; B373 29 03                    ).
        clc                                     ; B375 18                       .
        adc     #$01                            ; B376 69 01                    i.
        sta     sprite_x                        ; B378 85 E3                    ..
        sec                                     ; B37A 38                       8
        lda     sprite_y                        ; B37B A5 DF                    ..
        sbc     sprite_x                        ; B37D E5 E3                    ..
        sta     sprite_y                        ; B37F 85 DF                    ..
        sta     sprite_y                        ; B381 85 DF                    ..
        jmp     LB3D2                           ; B383 4C D2 B3                 L..

; ----------------------------------------------------------------------------
LB386:  clc                                     ; B386 18                       .
        lda     random_seed                     ; B387 A5 C6                    ..
        and     #$03                            ; B389 29 03                    ).
        clc                                     ; B38B 18                       .
        adc     #$01                            ; B38C 69 01                    i.
        adc     sprite_y                        ; B38E 65 DF                    e.
        sta     sprite_y                        ; B390 85 DF                    ..
        cmp     #$B0                            ; B392 C9 B0                    ..
        bcc     LB3D2                           ; B394 90 3C                    .<
        lda     #$20                            ; B396 A9 20                    . 
        sta     sprite_y                        ; B398 85 DF                    ..
        jmp     LB3D2                           ; B39A 4C D2 B3                 L..

; ----------------------------------------------------------------------------
LB39D:  lda     sprite_y                        ; B39D A5 DF                    ..
        cmp     ship_y_pos                      ; B39F C5 C4                    ..
        bcc     LB3BE                           ; B3A1 90 1B                    ..
        lda     random_seed                     ; B3A3 A5 C6                    ..
        and     #$03                            ; B3A5 29 03                    ).
        clc                                     ; B3A7 18                       .
        adc     #$01                            ; B3A8 69 01                    i.
        sta     sprite_x                        ; B3AA 85 E3                    ..
        sec                                     ; B3AC 38                       8
        lda     sprite_y                        ; B3AD A5 DF                    ..
        sbc     sprite_x                        ; B3AF E5 E3                    ..
        sta     sprite_y                        ; B3B1 85 DF                    ..
        cmp     #$20                            ; B3B3 C9 20                    . 
        bcs     LB3D2                           ; B3B5 B0 1B                    ..
        lda     #$B0                            ; B3B7 A9 B0                    ..
        sta     sprite_y                        ; B3B9 85 DF                    ..
        jmp     LB3D2                           ; B3BB 4C D2 B3                 L..

; ----------------------------------------------------------------------------
LB3BE:  clc                                     ; B3BE 18                       .
        lda     random_seed                     ; B3BF A5 C6                    ..
        and     #$03                            ; B3C1 29 03                    ).
        clc                                     ; B3C3 18                       .
        adc     #$01                            ; B3C4 69 01                    i.
        adc     sprite_y                        ; B3C6 65 DF                    e.
        sta     sprite_y                        ; B3C8 85 DF                    ..
        cmp     #$B0                            ; B3CA C9 B0                    ..
        bcc     LB3D2                           ; B3CC 90 04                    ..
        lda     #$20                            ; B3CE A9 20                    . 
        sta     sprite_y                        ; B3D0 85 DF                    ..
LB3D2:  lda     animation_counter               ; B3D2 A5 85                    ..
        and     #$02                            ; B3D4 29 02                    ).
        lsr     a                               ; B3D6 4A                       J
        clc                                     ; B3D7 18                       .
        adc     #$03                            ; B3D8 69 03                    i.
        sta     $88                             ; B3DA 85 88                    ..
        lda     #$03                            ; B3DC A9 03                    ..
        sta     $94                             ; B3DE 85 94                    ..
        lda     animation_counter               ; B3E0 A5 85                    ..
        adc     #$06                            ; B3E2 69 06                    i.
        and     #$0F                            ; B3E4 29 0F                    ).
        bne     LB3EB                           ; B3E6 D0 03                    ..
        jsr     L9A9C                           ; B3E8 20 9C 9A                  ..
LB3EB:  jsr     ram_self_destruct_1             ; B3EB 20 7F B4                  ..
        jmp     LA5B2                           ; B3EE 4C B2 A5                 L..

; ----------------------------------------------------------------------------
spawn_bomber:
        inc     enemy_count                     ; B3F1 E6 9C                    ..
        lda     current_sprite                  ; B3F3 A5 F9                    ..
        cmp     #$0C                            ; B3F5 C9 0C                    ..
        bcs     LB409                           ; B3F7 B0 10                    ..
        sec                                     ; B3F9 38                       8
        lda     $DD                             ; B3FA A5 DD                    ..
        sbc     #$02                            ; B3FC E9 02                    ..
        sta     $DD                             ; B3FE 85 DD                    ..
        lda     $DE                             ; B400 A5 DE                    ..
        sbc     #$00                            ; B402 E9 00                    ..
        sta     $DE                             ; B404 85 DE                    ..
        jmp     LB416                           ; B406 4C 16 B4                 L..

; ----------------------------------------------------------------------------
LB409:  clc                                     ; B409 18                       .
        lda     $DD                             ; B40A A5 DD                    ..
        adc     #$02                            ; B40C 69 02                    i.
        sta     $DD                             ; B40E 85 DD                    ..
        lda     $DE                             ; B410 A5 DE                    ..
        adc     #$00                            ; B412 69 00                    i.
        sta     $DE                             ; B414 85 DE                    ..
LB416:  ldx     $98                             ; B416 A6 98                    ..
        lda     animation_counter               ; B418 A5 85                    ..
        and     #$03                            ; B41A 29 03                    ).
        bne     LB421                           ; B41C D0 03                    ..
        inc     sprite_list+128,x               ; B41E FE 6B 0B                 .k.
LB421:  lda     sprite_list+128,x               ; B421 BD 6B 0B                 .k.
        and     #$1F                            ; B424 29 1F                    ).
        tax                                     ; B426 AA                       .
        cmp     #$08                            ; B427 C9 08                    ..
        beq     LB42F                           ; B429 F0 04                    ..
        cmp     #$18                            ; B42B C9 18                    ..
        bne     LB43B                           ; B42D D0 0C                    ..
LB42F:  lda     RANDOM                          ; B42F AD 0A D2                 ...
        bpl     LB43B                           ; B432 10 07                    ..
        txa                                     ; B434 8A                       .
        clc                                     ; B435 18                       .
        adc     #$0E                            ; B436 69 0E                    i.
        and     #$1F                            ; B438 29 1F                    ).
        tax                                     ; B43A AA                       .
LB43B:  clc                                     ; B43B 18                       .
        lda     sprite_y                        ; B43C A5 DF                    ..
        adc     swarmer_spawn_y_offsets,x       ; B43E 7D 68 B5                 }h.
        sta     sprite_y                        ; B441 85 DF                    ..
        cmp     #$20                            ; B443 C9 20                    . 
        bcc     LB452                           ; B445 90 0B                    ..
        cmp     #$B0                            ; B447 C9 B0                    ..
        bcc     LB456                           ; B449 90 0B                    ..
        lda     #$20                            ; B44B A9 20                    . 
        sta     sprite_y                        ; B44D 85 DF                    ..
        jmp     LB456                           ; B44F 4C 56 B4                 LV.

; ----------------------------------------------------------------------------
LB452:  lda     #$B0                            ; B452 A9 B0                    ..
        sta     sprite_y                        ; B454 85 DF                    ..
LB456:  lda     ship_y_pos                      ; B456 A5 C4                    ..
        sec                                     ; B458 38                       8
        sbc     sprite_y                        ; B459 E5 DF                    ..
        bcs     LB461                           ; B45B B0 04                    ..
        eor     #$FF                            ; B45D 49 FF                    I.
        adc     #$01                            ; B45F 69 01                    i.
LB461:  cmp     #$20                            ; B461 C9 20                    . 
        bcs     LB472                           ; B463 B0 0D                    ..
        lda     #$0B                            ; B465 A9 0B                    ..
        sta     $94                             ; B467 85 94                    ..
        lda     animation_counter               ; B469 A5 85                    ..
        and     #$03                            ; B46B 29 03                    ).
        bne     LB472                           ; B46D D0 03                    ..
        jsr     L9A9C                           ; B46F 20 9C 9A                  ..
LB472:  lda     animation_counter               ; B472 A5 85                    ..
        and     #$02                            ; B474 29 02                    ).
        lsr     a                               ; B476 4A                       J
        clc                                     ; B477 18                       .
        adc     #$0E                            ; B478 69 0E                    i.
        sta     $88                             ; B47A 85 88                    ..
        jmp     LA5B2                           ; B47C 4C B2 A5                 L..

; ----------------------------------------------------------------------------
; copy protection, causes game to crash next time the player gets killed. called from several places in the code.
ram_self_destruct_1:
        lda     #$02                            ; B47F A9 02                    ..
        sta     ae_loop                         ; B481 8D 3D 98                 .=.
        rts                                     ; B484 60                       `

; ----------------------------------------------------------------------------
spawn_pod:
        inc     enemy_count                     ; B485 E6 9C                    ..
        inc     sprite_y                        ; B487 E6 DF                    ..
        lda     sprite_y                        ; B489 A5 DF                    ..
        cmp     #$B0                            ; B48B C9 B0                    ..
        bcc     LB493                           ; B48D 90 04                    ..
        lda     #$20                            ; B48F A9 20                    . 
        sta     sprite_y                        ; B491 85 DF                    ..
LB493:  inc     $DD                             ; B493 E6 DD                    ..
        bne     LB499                           ; B495 D0 02                    ..
        inc     $DE                             ; B497 E6 DE                    ..
LB499:  lda     animation_counter               ; B499 A5 85                    ..
        and     #$01                            ; B49B 29 01                    ).
        clc                                     ; B49D 18                       .
        adc     #$15                            ; B49E 69 15                    i.
        sta     $88                             ; B4A0 85 88                    ..
        jmp     LA5B2                           ; B4A2 4C B2 A5                 L..

; ----------------------------------------------------------------------------
spawn_swarmer:
        inc     enemy_count                     ; B4A5 E6 9C                    ..
        sec                                     ; B4A7 38                       8
        lda     $91                             ; B4A8 A5 91                    ..
        sbc     $DD                             ; B4AA E5 DD                    ..
        sta     sprite_x                        ; B4AC 85 E3                    ..
        lda     $92                             ; B4AE A5 92                    ..
        sbc     $DE                             ; B4B0 E5 DE                    ..
        sta     $E4                             ; B4B2 85 E4                    ..
        bcs     LB4C8                           ; B4B4 B0 12                    ..
        lda     sprite_x                        ; B4B6 A5 E3                    ..
        eor     #$FF                            ; B4B8 49 FF                    I.
        sta     sprite_x                        ; B4BA 85 E3                    ..
        lda     $E4                             ; B4BC A5 E4                    ..
        eor     #$FF                            ; B4BE 49 FF                    I.
        sta     $E4                             ; B4C0 85 E4                    ..
        inc     sprite_x                        ; B4C2 E6 E3                    ..
        bne     LB4C8                           ; B4C4 D0 02                    ..
        inc     $E4                             ; B4C6 E6 E4                    ..
LB4C8:  lda     $E4                             ; B4C8 A5 E4                    ..
        bne     LB4D2                           ; B4CA D0 06                    ..
        lda     sprite_x                        ; B4CC A5 E3                    ..
        cmp     #$64                            ; B4CE C9 64                    .d
        bcc     LB4DE                           ; B4D0 90 0C                    ..
LB4D2:  lda     $DD                             ; B4D2 A5 DD                    ..
        cmp     $91                             ; B4D4 C5 91                    ..
        lda     $DE                             ; B4D6 A5 DE                    ..
        sbc     $92                             ; B4D8 E5 92                    ..
        ror     a                               ; B4DA 6A                       j
        sta     sprite_list+128,y               ; B4DB 99 6B 0B                 .k.
LB4DE:  ldy     $98                             ; B4DE A4 98                    ..
        lda     sprite_list+128,y               ; B4E0 B9 6B 0B                 .k.
        bmi     LB4F5                           ; B4E3 30 10                    0.
        clc                                     ; B4E5 18                       .
        lda     $DD                             ; B4E6 A5 DD                    ..
        adc     #$02                            ; B4E8 69 02                    i.
        sta     $DD                             ; B4EA 85 DD                    ..
        lda     $DE                             ; B4EC A5 DE                    ..
        adc     #$00                            ; B4EE 69 00                    i.
        sta     $DE                             ; B4F0 85 DE                    ..
        jmp     LB502                           ; B4F2 4C 02 B5                 L..

; ----------------------------------------------------------------------------
LB4F5:  sec                                     ; B4F5 38                       8
        lda     $DD                             ; B4F6 A5 DD                    ..
        sbc     #$02                            ; B4F8 E9 02                    ..
        sta     $DD                             ; B4FA 85 DD                    ..
        lda     $DE                             ; B4FC A5 DE                    ..
        sbc     #$00                            ; B4FE E9 00                    ..
        sta     $DE                             ; B500 85 DE                    ..
LB502:  ldx     $98                             ; B502 A6 98                    ..
        lda     animation_counter               ; B504 A5 85                    ..
        and     #$01                            ; B506 29 01                    ).
        bne     LB50D                           ; B508 D0 03                    ..
        inc     sprite_list+129,x               ; B50A FE 6C 0B                 .l.
LB50D:  lda     sprite_list+129,x               ; B50D BD 6C 0B                 .l.
        and     #$1F                            ; B510 29 1F                    ).
        tax                                     ; B512 AA                       .
        clc                                     ; B513 18                       .
        lda     sprite_y                        ; B514 A5 DF                    ..
        adc     swarmer_spawn_y_offsets,x       ; B516 7D 68 B5                 }h.
        sta     sprite_y                        ; B519 85 DF                    ..
        lda     sprite_y                        ; B51B A5 DF                    ..
        cmp     ship_y_pos                      ; B51D C5 C4                    ..
        bcc     LB526                           ; B51F 90 05                    ..
        dec     sprite_y                        ; B521 C6 DF                    ..
        jmp     LB528                           ; B523 4C 28 B5                 L(.

; ----------------------------------------------------------------------------
LB526:  inc     sprite_y                        ; B526 E6 DF                    ..
LB528:  cmp     #$20                            ; B528 C9 20                    . 
        bcs     LB533                           ; B52A B0 07                    ..
        lda     #$B0                            ; B52C A9 B0                    ..
        sta     sprite_y                        ; B52E 85 DF                    ..
        jmp     LB53B                           ; B530 4C 3B B5                 L;.

; ----------------------------------------------------------------------------
LB533:  cmp     #$B0                            ; B533 C9 B0                    ..
        bcc     LB53B                           ; B535 90 04                    ..
        lda     #$20                            ; B537 A9 20                    . 
        sta     sprite_y                        ; B539 85 DF                    ..
LB53B:  lda     #$03                            ; B53B A9 03                    ..
        sta     $94                             ; B53D 85 94                    ..
        lda     animation_counter               ; B53F A5 85                    ..
        adc     #$04                            ; B541 69 04                    i.
        and     #$0F                            ; B543 29 0F                    ).
        bne     LB561                           ; B545 D0 1A                    ..
        lda     $DD                             ; B547 A5 DD                    ..
        cmp     $91                             ; B549 C5 91                    ..
        lda     $DE                             ; B54B A5 DE                    ..
        sbc     $92                             ; B54D E5 92                    ..
        bcs     LB559                           ; B54F B0 08                    ..
        lda     sprite_list+128,y               ; B551 B9 6B 0B                 .k.
        bpl     LB55E                           ; B554 10 08                    ..
        jmp     LB561                           ; B556 4C 61 B5                 La.

; ----------------------------------------------------------------------------
LB559:  lda     sprite_list+128,y               ; B559 B9 6B 0B                 .k.
        bpl     LB561                           ; B55C 10 03                    ..
LB55E:  jsr     L9A9C                           ; B55E 20 9C 9A                  ..
LB561:  lda     #$17                            ; B561 A9 17                    ..
        sta     $88                             ; B563 85 88                    ..
        jmp     LA5B2                           ; B565 4C B2 A5                 L..

; ----------------------------------------------------------------------------
; XXX I *think* that's what this is
swarmer_spawn_y_offsets:
        .byte   $FD,$FD,$FD,$FE,$FE,$FF,$FF,$00 ; B568 FD FD FD FE FE FF FF 00  ........
        .byte   $00,$01,$01,$02,$02,$03,$03,$03 ; B570 00 01 01 02 02 03 03 03  ........
        .byte   $03,$03,$03,$02,$02,$01,$01,$00 ; B578 03 03 03 02 02 01 01 00  ........
        .byte   $00,$FF,$FF,$FE,$FE,$FD,$FD,$FD ; B580 00 FF FF FE FE FD FD FD  ........
; ----------------------------------------------------------------------------
; zero out memory to avoid leaving trails
erase_ship:
        lda     ship_y_pos                      ; B588 A5 C4                    ..
        sta     sprite_y                        ; B58A 85 DF                    ..
        lda     ship_x_pos                      ; B58C A5 C3                    ..
        sta     sprite_x                        ; B58E 85 E3                    ..
        lda     #$00                            ; B590 A9 00                    ..
        sta     current_sprite                  ; B592 85 F9                    ..
        jsr     erase_sprite                    ; B594 20 2C AB                  ,.
        lda     sprite_x                        ; B597 A5 E3                    ..
        clc                                     ; B599 18                       .
        adc     #$05                            ; B59A 69 05                    i.
        sta     sprite_x                        ; B59C 85 E3                    ..
        jmp     erase_sprite                    ; B59E 4C 2C AB                 L,.

; ----------------------------------------------------------------------------
; draw the player's ship (in playfield, or lives in HUD), but not the rocket exhaust
draw_ship:
        lda     ship_y_pos                      ; B5A1 A5 C4                    ..
        sta     sprite_y                        ; B5A3 85 DF                    ..
        lda     ship_x_pos                      ; B5A5 A5 C3                    ..
        sta     sprite_x                        ; B5A7 85 E3                    ..
        lda     animation_counter               ; B5A9 A5 85                    ..
        and     #$02                            ; B5AB 29 02                    ).
        bne     LB5D5                           ; B5AD D0 26                    .&
        lda     ship_direction                  ; B5AF A5 C5                    ..
        bpl     LB5C4                           ; B5B1 10 11                    ..
        lda     #$09                            ; B5B3 A9 09                    ..
        jsr     draw_sprite_left_copy           ; B5B5 20 00 1F                  ..
        clc                                     ; B5B8 18                       .
        lda     sprite_x                        ; B5B9 A5 E3                    ..
        adc     #$05                            ; B5BB 69 05                    i.
        sta     sprite_x                        ; B5BD 85 E3                    ..
        lda     #$0A                            ; B5BF A9 0A                    ..
        jmp     draw_sprite_right_copy          ; B5C1 4C 80 1F                 L..

; ----------------------------------------------------------------------------
LB5C4:  lda     #$05                            ; B5C4 A9 05                    ..
        jsr     draw_sprite_left_copy           ; B5C6 20 00 1F                  ..
        clc                                     ; B5C9 18                       .
        lda     sprite_x                        ; B5CA A5 E3                    ..
        adc     #$05                            ; B5CC 69 05                    i.
        sta     sprite_x                        ; B5CE 85 E3                    ..
        lda     #$06                            ; B5D0 A9 06                    ..
        jmp     draw_sprite_right_copy          ; B5D2 4C 80 1F                 L..

; ----------------------------------------------------------------------------
LB5D5:  lda     ship_direction                  ; B5D5 A5 C5                    ..
        bpl     LB5EA                           ; B5D7 10 11                    ..
        lda     #$0B                            ; B5D9 A9 0B                    ..
        jsr     draw_sprite_left_copy           ; B5DB 20 00 1F                  ..
        clc                                     ; B5DE 18                       .
        lda     sprite_x                        ; B5DF A5 E3                    ..
        adc     #$05                            ; B5E1 69 05                    i.
        sta     sprite_x                        ; B5E3 85 E3                    ..
        lda     #$0C                            ; B5E5 A9 0C                    ..
        jmp     draw_sprite_right_copy          ; B5E7 4C 80 1F                 L..

; ----------------------------------------------------------------------------
LB5EA:  lda     #$07                            ; B5EA A9 07                    ..
        jsr     draw_sprite_left_copy           ; B5EC 20 00 1F                  ..
        clc                                     ; B5EF 18                       .
        lda     sprite_x                        ; B5F0 A5 E3                    ..
        adc     #$05                            ; B5F2 69 05                    i.
        sta     sprite_x                        ; B5F4 85 E3                    ..
        lda     #$08                            ; B5F6 A9 08                    ..
        jmp     draw_sprite_right_copy          ; B5F8 4C 80 1F                 L..

; ----------------------------------------------------------------------------
; if hit, explode the ship and return with carry set. otherwise, return with carry clear.
check_ship_collision:
        bit     invuln_flag                     ; B5FB 24 ED                    $.
        bpl     not_invuln                      ; B5FD 10 01                    ..
        rts                                     ; B5FF 60                       `

; ----------------------------------------------------------------------------
; bounding box is 20x10, with X offset 3 from actual ship position.
not_invuln:
        lda     ship_y_pos                      ; B600 A5 C4                    ..
        sec                                     ; B602 38                       8
        sbc     sprite_y                        ; B603 E5 DF                    ..
        bcs     ni_cmp_abs_y                    ; B605 B0 04                    ..
        eor     #$FF                            ; B607 49 FF                    I.
        adc     #$01                            ; B609 69 01                    i.
; if(abs(ship_y_pos - sprite_y) < 6) goto ship_collision;
ni_cmp_abs_y:
        cmp     #$06                            ; B60B C9 06                    ..
        bcs     jmp_no_coll                     ; B60D B0 12                    ..
        lda     ship_x_pos                      ; B60F A5 C3                    ..
        clc                                     ; B611 18                       .
        adc     #$03                            ; B612 69 03                    i.
        sec                                     ; B614 38                       8
        sbc     sprite_x                        ; B615 E5 E3                    ..
        bcs     ni_cmp_abs_x                    ; B617 B0 04                    ..
        eor     #$FF                            ; B619 49 FF                    I.
        adc     #$01                            ; B61B 69 01                    i.
; if(abs(ship_x_pos - sprite_x) < 11) goto ship_collision;
ni_cmp_abs_x:
        cmp     #$0B                            ; B61D C9 0B                    ..
        bcc     ship_collision                  ; B61F 90 03                    ..
jmp_no_coll:
        jmp     no_collision                    ; B621 4C 67 B7                 Lg.

; ----------------------------------------------------------------------------
; player ran into something
ship_collision:
        jsr     erase_exhaust                   ; B624 20 62 99                  b.
        sec                                     ; B627 38                       8
        ror     ship_dead_flag                  ; B628 66 EF                    f.
        ldy     $98                             ; B62A A4 98                    ..
        lda     #$00                            ; B62C A9 00                    ..
        sta     sprite_list,y                   ; B62E 99 EB 0A                 ...
        lda     sprite_list+3,y                 ; B631 B9 EE 0A                 ...
        sta     current_sprite                  ; B634 85 F9                    ..
        jsr     add_cursprite_points            ; B636 20 AE A7                  ..
        jsr     draw_scores                     ; B639 20 42 94                  B.
        ldy     $98                             ; B63C A4 98                    ..
        lda     sprite_list+3,y                 ; B63E B9 EE 0A                 ...
        and     #$07                            ; B641 29 07                    ).
        cmp     #$05                            ; B643 C9 05                    ..
        bne     no_swarmers                     ; B645 D0 03                    ..
        jsr     spawn_swarmers                  ; B647 20 11 A7                  ..
no_swarmers:
        sec                                     ; B64A 38                       8
        rts                                     ; B64B 60                       `

; ----------------------------------------------------------------------------
; explosion animation, then bookkeeping
start_player_death:
        lda     #$00                            ; B64C A9 00                    ..
        sta     ship_delta                      ; B64E 85 D5                    ..
        jsr     clear_scanner_draw_planet_and_humans; B650 20 5E 9E              ^.
        lda     #$00                            ; B653 A9 00                    ..
        sta     ship_dead_flag                  ; B655 85 EF                    ..
        jsr     clear_player_shots              ; B657 20 F1 B7                  ..
        lda     #$08                            ; B65A A9 08                    ..
; flash the ship's colors just before it explodes
flash_ship:
        pha                                     ; B65C 48                       H
        sec                                     ; B65D 38                       8
        ror     invuln_flag                     ; B65E 66 ED                    f.
flash_wait_1:
        bit     draw_ok_flag                    ; B660 24 AB                    $.
        bpl     flash_wait_1                    ; B662 10 FC                    ..
        jsr     draw_ship                       ; B664 20 A1 B5                  ..
        jsr     LA4CC                           ; B667 20 CC A4                  ..
        lda     #$38                            ; B66A A9 38                    .8
        sta     COLOR2                          ; B66C 8D C6 02                 ...
flash_wait_2:
        lda     draw_ok_flag                    ; B66F A5 AB                    ..
        bmi     flash_wait_2                    ; B671 30 FC                    0.
flash_wait_3:
        bit     draw_ok_flag                    ; B673 24 AB                    $.
        bpl     flash_wait_3                    ; B675 10 FC                    ..
        jsr     draw_ship                       ; B677 20 A1 B5                  ..
        jsr     LA4CC                           ; B67A 20 CC A4                  ..
        lda     #$7E                            ; B67D A9 7E                    .~
        sta     COLOR2                          ; B67F 8D C6 02                 ...
        pla                                     ; B682 68                       h
        sec                                     ; B683 38                       8
        sbc     #$01                            ; B684 E9 01                    ..
        bne     flash_ship                      ; B686 D0 D4                    ..
        lda     #$00                            ; B688 A9 00                    ..
        sta     invuln_flag                     ; B68A 85 ED                    ..
        jsr     erase_ship                      ; B68C 20 88 B5                  ..
        lda     #$00                            ; B68F A9 00                    ..
        sta     AUDF2                           ; B691 8D 02 D2                 ...
        sta     AUDC2                           ; B694 8D 03 D2                 ...
        jsr     play_ship_died                  ; B697 20 6A 8E                  j.
        lda     #$0F                            ; B69A A9 0F                    ..
        sta     COLOR4                          ; B69C 8D C8 02                 ...
        lda     #$80                            ; B69F A9 80                    ..
        jsr     delay_loop                      ; B6A1 20 74 88                  t.
        lda     #$00                            ; B6A4 A9 00                    ..
        sta     COLOR4                          ; B6A6 8D C8 02                 ...
        lsr     $AD                             ; B6A9 46 AD                    F.
        jsr     draw_scores                     ; B6AB 20 42 94                  B.
        jsr     ship_explosion                  ; B6AE 20 D9 97                  ..
        lda     #$7E                            ; B6B1 A9 7E                    .~
        sta     COLOR2                          ; B6B3 8D C6 02                 ...
        jsr     draw_scores                     ; B6B6 20 42 94                  B.
        lda     enemy_count                     ; B6B9 A5 9C                    ..
        ora     landers_to_spawn                ; B6BB 05 9B                    ..
        ora     baiter_count                    ; B6BD 05 9D                    ..
        bne     player_died_same_level          ; B6BF D0 0E                    ..
; player collided with last enemy, cleared the level, but died
player_died_next_level:
        jsr     clear_baiters                   ; B6C1 20 6D B8                  m.
        jsr     clear_temp_enemies              ; B6C4 20 69 B7                  i.
        dec     lives                           ; B6C7 C6 9E                    ..
        sec                                     ; B6C9 38                       8
        ror     $F7                             ; B6CA 66 F7                    f.
        jmp     next_level                      ; B6CC 4C C9 83                 L..

; ----------------------------------------------------------------------------
player_died_same_level:
        dec     lives                           ; B6CF C6 9E                    ..
LB6D1:  lsr     $F7                             ; B6D1 46 F7                    F.
        lda     lives                           ; B6D3 A5 9E                    ..
        beq     out_of_lives                    ; B6D5 F0 37                    .7
        jsr     clear_baiters                   ; B6D7 20 6D B8                  m.
        jsr     clear_temp_enemies              ; B6DA 20 69 B7                  i.
        lda     players                         ; B6DD A5 E2                    ..
        cmp     #$01                            ; B6DF C9 01                    ..
        beq     LB70B                           ; B6E1 F0 28                    .(
LB6E3:  lda     current_player                  ; B6E3 A5 F1                    ..
        cmp     #$01                            ; B6E5 C9 01                    ..
        beq     LB6F2                           ; B6E7 F0 09                    ..
        jsr     save_p2_state                   ; B6E9 20 0D 8A                  ..
        jsr     load_p1_state                   ; B6EC 20 61 8A                  a.
        jmp     LB6F8                           ; B6EF 4C F8 B6                 L..

; ----------------------------------------------------------------------------
LB6F2:  jsr     save_p1_state                   ; B6F2 20 B9 89                  ..
        jsr     load_p2_state                   ; B6F5 20 B5 8A                  ..
LB6F8:  lda     lives                           ; B6F8 A5 9E                    ..
        bne     LB705                           ; B6FA D0 09                    ..
        lda     current_player                  ; B6FC A5 F1                    ..
        eor     #$03                            ; B6FE 49 03                    I.
        sta     current_player                  ; B700 85 F1                    ..
        jmp     LB6E3                           ; B702 4C E3 B6                 L..

; ----------------------------------------------------------------------------
LB705:  lda     current_player                  ; B705 A5 F1                    ..
        eor     #$03                            ; B707 49 03                    I.
        sta     current_player                  ; B709 85 F1                    ..
LB70B:  jmp     clear_enemy_explosions          ; B70B 4C 5B 84                 L[.

; ----------------------------------------------------------------------------
out_of_lives:
        jsr     clear_screen                    ; B70E 20 A1 B8                  ..
        jsr     draw_scanner_border_and_planet  ; B711 20 B1 9F                  ..
        jsr     draw_p1_lives_and_bombs         ; B714 20 B0 86                  ..
        jsr     draw_p2_lives_and_bombs         ; B717 20 80 87                  ..
        jsr     draw_scores                     ; B71A 20 42 94                  B.
        lda     players                         ; B71D A5 E2                    ..
        cmp     #$01                            ; B71F C9 01                    ..
        beq     LB732                           ; B721 F0 0F                    ..
        lda     current_player                  ; B723 A5 F1                    ..
        cmp     #$01                            ; B725 C9 01                    ..
        beq     LB72F                           ; B727 F0 06                    ..
        jsr     print_p2_text                   ; B729 20 3E 8B                  >.
        jmp     LB732                           ; B72C 4C 32 B7                 L2.

; ----------------------------------------------------------------------------
LB72F:  jsr     print_p1_text                   ; B72F 20 09 8B                  ..
LB732:  jsr     print_game_over                 ; B732 20 1E B8                  ..
        lda     #$00                            ; B735 A9 00                    ..
        sta     start_flag                      ; B737 85 BE                    ..
        sta     select_flag                     ; B739 85 B0                    ..
        lda     players                         ; B73B A5 E2                    ..
        cmp     #$01                            ; B73D C9 01                    ..
        beq     LB753                           ; B73F F0 12                    ..
        lda     current_player                  ; B741 A5 F1                    ..
        cmp     #$01                            ; B743 C9 01                    ..
        beq     LB74E                           ; B745 F0 07                    ..
        lda     p1_sav_lives                    ; B747 AD C6 17                 ...
        beq     LB753                           ; B74A F0 07                    ..
        bne     LB6E3                           ; B74C D0 95                    ..
LB74E:  lda     p2_sav_lives                    ; B74E AD C6 19                 ...
        bne     LB6E3                           ; B751 D0 90                    ..
LB753:  jsr     read_consol                     ; B753 20 A0 BA                  ..
        sec                                     ; B756 38                       8
        ror     pause_flag                      ; B757 66 AF                    f.
        bit     start_flag                      ; B759 24 BE                    $.
        bpl     LB760                           ; B75B 10 03                    ..
        jmp     game_on                         ; B75D 4C 69 83                 Li.

; ----------------------------------------------------------------------------
LB760:  bit     select_flag                     ; B760 24 B0                    $.
        bpl     LB753                           ; B762 10 EF                    ..
        jmp     init_title_screen               ; B764 4C 31 80                 L1.

; ----------------------------------------------------------------------------
no_collision:
        clc                                     ; B767 18                       .
        rts                                     ; B768 60                       `

; ----------------------------------------------------------------------------
; remove baiters, enemy shots, bombs. called when the player dies.
clear_temp_enemies:
        lda     #$00                            ; B769 A9 00                    ..
        sta     $9F                             ; B76B 85 9F                    ..
        jmp     LB781                           ; B76D 4C 81 B7                 L..

; ----------------------------------------------------------------------------
LB770:  lda     $9F                             ; B770 A5 9F                    ..
        clc                                     ; B772 18                       .
        adc     #$04                            ; B773 69 04                    i.
        sta     $9F                             ; B775 85 9F                    ..
        bpl     LB781                           ; B777 10 08                    ..
        lda     #$64                            ; B779 A9 64                    .d
        sta     baiter_count                    ; B77B 85 9D                    ..
        jsr     LB7E0                           ; B77D 20 E0 B7                  ..
        rts                                     ; B780 60                       `

; ----------------------------------------------------------------------------
LB781:  ldy     $9F                             ; B781 A4 9F                    ..
        lda     sprite_list,y                   ; B783 B9 EB 0A                 ...
        beq     LB770                           ; B786 F0 E8                    ..
        lda     sprite_list+3,y                 ; B788 B9 EE 0A                 ...
        and     #$07                            ; B78B 29 07                    ).
        beq     LB7BD                           ; B78D F0 2E                    ..
        cmp     #$01                            ; B78F C9 01                    ..
        beq     LB7AA                           ; B791 F0 17                    ..
        cmp     #$07                            ; B793 C9 07                    ..
        beq     LB79B                           ; B795 F0 04                    ..
        cmp     #$03                            ; B797 C9 03                    ..
        bne     LB7AF                           ; B799 D0 14                    ..
LB79B:  ldy     $9F                             ; B79B A4 9F                    ..
        lda     #$00                            ; B79D A9 00                    ..
        sta     sprite_list,y                   ; B79F 99 EB 0A                 ...
        lda     #$80                            ; B7A2 A9 80                    ..
        sta     sprite_list+2,y                 ; B7A4 99 ED 0A                 ...
        jmp     LB770                           ; B7A7 4C 70 B7                 Lp.

; ----------------------------------------------------------------------------
LB7AA:  lda     #$01                            ; B7AA A9 01                    ..
        sta     sprite_list+3,y                 ; B7AC 99 EE 0A                 ...
LB7AF:  jsr     get_spawn_pos                   ; B7AF 20 0C 8D                  ..
        lda     sprite_list+3,y                 ; B7B2 B9 EE 0A                 ...
        sta     current_sprite                  ; B7B5 85 F9                    ..
        jsr     spawn_sprite                    ; B7B7 20 ED AB                  ..
        jmp     LB79B                           ; B7BA 4C 9B B7                 L..

; ----------------------------------------------------------------------------
LB7BD:  clc                                     ; B7BD 18                       .
        lda     sprite_list+1,y                 ; B7BE B9 EC 0A                 ...
        adc     #$AB                            ; B7C1 69 AB                    i.
        sta     tmp_ptr                         ; B7C3 85 E7                    ..
        lda     sprite_list+2,y                 ; B7C5 B9 ED 0A                 ...
        adc     #$05                            ; B7C8 69 05                    i.
        sta     tmp_ptr+1                       ; B7CA 85 E8                    ..
        ldy     #$00                            ; B7CC A0 00                    ..
        lda     (tmp_ptr),y                     ; B7CE B1 E7                    ..
        sec                                     ; B7D0 38                       8
        sbc     #$04                            ; B7D1 E9 04                    ..
        ldy     $9F                             ; B7D3 A4 9F                    ..
        sta     sprite_list,y                   ; B7D5 99 EB 0A                 ...
        lda     #$00                            ; B7D8 A9 00                    ..
        sta     sprite_list+3,y                 ; B7DA 99 EE 0A                 ...
        jmp     LB770                           ; B7DD 4C 70 B7                 Lp.

; ----------------------------------------------------------------------------
LB7E0:  ldy     #$00                            ; B7E0 A0 00                    ..
LB7E2:  lda     #$30                            ; B7E2 A9 30                    .0
        sta     actor_list+4,y                  ; B7E4 99 6F 0C                 .o.
        tya                                     ; B7E7 98                       .
        clc                                     ; B7E8 18                       .
        adc     #$06                            ; B7E9 69 06                    i.
        tay                                     ; B7EB A8                       .
        cpy     #$C0                            ; B7EC C0 C0                    ..
        bcc     LB7E2                           ; B7EE 90 F2                    ..
        rts                                     ; B7F0 60                       `

; ----------------------------------------------------------------------------
; clear player_shots table and erase shot graphics. called when player dies or enters hyperspace
clear_player_shots:
        ldx     #$00                            ; B7F1 A2 00                    ..
cps_next:
        lda     player_shots_y,x                ; B7F3 BD 1A 05                 ...
        bne     cps_clear                       ; B7F6 D0 0A                    ..
; see if this shot exists
cps_check:
        txa                                     ; B7F8 8A                       .
        clc                                     ; B7F9 18                       .
        adc     #$04                            ; B7FA 69 04                    i.
        tax                                     ; B7FC AA                       .
        cpx     #$10                            ; B7FD E0 10                    ..
        bcc     cps_next                        ; B7FF 90 F2                    ..
        rts                                     ; B801 60                       `

; ----------------------------------------------------------------------------
; shot exists, clear it
cps_clear:
        tay                                     ; B802 A8                       .
        lda     #$00                            ; B803 A9 00                    ..
        sta     player_shots_y,x                ; B805 9D 1A 05                 ...
        lda     screen_hi_ptrs,y                ; B808 B9 00 1E                 ...
        sta     screen_ptr+1                    ; B80B 85 C1                    ..
        lda     screen_lo_ptrs,y                ; B80D B9 00 1D                 ...
        sta     screen_ptr                      ; B810 85 C0                    ..
        ldy     #$27                            ; B812 A0 27                    .'
cps_clear_loop:
        lda     #$00                            ; B814 A9 00                    ..
        sta     (screen_ptr),y                  ; B816 91 C0                    ..
        dey                                     ; B818 88                       .
        bpl     cps_clear_loop                  ; B819 10 F9                    ..
        jmp     cps_check                       ; B81B 4C F8 B7                 L..

; ----------------------------------------------------------------------------
print_game_over:
        lda     #$0C                            ; B81E A9 0C                    ..
        sta     cursor_y                        ; B820 8D 3A 14                 .:.
        lda     #$00                            ; B823 A9 00                    ..
        sta     cursor_x                        ; B825 8D 39 14                 .9.
        ldy     #$00                            ; B828 A0 00                    ..
pgo_nextchar:
        lda     game_over_text,y                ; B82A B9 44 B8                 .D.
        beq     pgo_delay                       ; B82D F0 06                    ..
        jsr     printchar                       ; B82F 20 2E 97                  ..
        iny                                     ; B832 C8                       .
        bne     pgo_nextchar                    ; B833 D0 F5                    ..
pgo_delay:
        lda     #$0A                            ; B835 A9 0A                    ..
pgo_delay_loop:
        pha                                     ; B837 48                       H
        lda     #$FF                            ; B838 A9 FF                    ..
        jsr     delay_loop                      ; B83A 20 74 88                  t.
        pla                                     ; B83D 68                       h
        sec                                     ; B83E 38                       8
        sbc     #$01                            ; B83F E9 01                    ..
        bne     pgo_delay_loop                  ; B841 D0 F4                    ..
        rts                                     ; B843 60                       `

; ----------------------------------------------------------------------------
; '           G A M E  O V E R             '
game_over_text:
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0 ; B844 A0 A0 A0 A0 A0 A0 A0 A0  ........
        .byte   $A0,$A0,$A0,$C7,$A0,$C1,$A0,$CD ; B84C A0 A0 A0 C7 A0 C1 A0 CD  ........
        .byte   $A0,$C5,$A0,$A0,$CF,$A0,$D6,$A0 ; B854 A0 C5 A0 A0 CF A0 D6 A0  ........
        .byte   $C5,$A0,$D2,$A0,$A0,$A0,$A0,$A0 ; B85C C5 A0 D2 A0 A0 A0 A0 A0  ........
        .byte   $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0 ; B864 A0 A0 A0 A0 A0 A0 A0 A0  ........
        .byte   $00                             ; B86C 00                       .
; ----------------------------------------------------------------------------
; XXX I think this is correct, but disabling it doesn't do what I think it should
clear_baiters:
        ldy     #$00                            ; B86D A0 00                    ..
        lda     #$00                            ; B86F A9 00                    ..
LB871:  lda     actor_list+3,y                  ; B871 B9 6E 0C                 .n.
        and     #$07                            ; B874 29 07                    ).
        cmp     #$07                            ; B876 C9 07                    ..
        bne     LB87F                           ; B878 D0 05                    ..
        lda     #$00                            ; B87A A9 00                    ..
        sta     actor_list,y                    ; B87C 99 6B 0C                 .k.
LB87F:  tya                                     ; B87F 98                       .
        clc                                     ; B880 18                       .
        adc     #$06                            ; B881 69 06                    i.
        tay                                     ; B883 A8                       .
        cpy     #$C0                            ; B884 C0 C0                    ..
        bcc     LB871                           ; B886 90 E9                    ..
        rts                                     ; B888 60                       `

; ----------------------------------------------------------------------------
init_hardware:
        sei                                     ; B889 78                       x
        cld                                     ; B88A D8                       .
        lda     #$00                            ; B88B A9 00                    ..
        sta     SDMCTL                          ; B88D 8D 2F 02                 ./.
        sta     DMACTL                          ; B890 8D 00 D4                 ...
        sta     NMIEN                           ; B893 8D 0E D4                 ...
        sta     POKMSK                          ; B896 85 10                    ..
        sta     IRQEN                           ; B898 8D 0E D2                 ...
        jsr     clear_screen                    ; B89B 20 A1 B8                  ..
        jmp     init_screen_ptrs                ; B89E 4C 02 B9                 L..

; ----------------------------------------------------------------------------
; zero out $2218 - $4017 (screen actually ends at $3fc7). the only place where ram above $3fff is accessed (written to, never read, so it's OK on a 16K Atari)
clear_screen:
        ldx     #$00                            ; B8A1 A2 00                    ..
        txa                                     ; B8A3 8A                       .
LB8A4:  sta     screen_ram,x                    ; B8A4 9D 18 22                 .."
        sta     screen_ram+256,x                ; B8A7 9D 18 23                 ..#
        sta     screen_ram+512,x                ; B8AA 9D 18 24                 ..$
        sta     screen_ram+768,x                ; B8AD 9D 18 25                 ..%
        sta     screen_ram+1024,x               ; B8B0 9D 18 26                 ..&
        sta     screen_ram+1280,x               ; B8B3 9D 18 27                 ..'
        sta     screen_ram+1536,x               ; B8B6 9D 18 28                 ..(
        sta     screen_ram+1792,x               ; B8B9 9D 18 29                 ..)
        sta     screen_ram+2048,x               ; B8BC 9D 18 2A                 ..*
        sta     screen_ram+2304,x               ; B8BF 9D 18 2B                 ..+
        sta     screen_ram+2560,x               ; B8C2 9D 18 2C                 ..,
        sta     screen_ram+2816,x               ; B8C5 9D 18 2D                 ..-
        sta     screen_ram+3072,x               ; B8C8 9D 18 2E                 ...
        sta     screen_ram+3328,x               ; B8CB 9D 18 2F                 ../
        sta     screen_ram+3584,x               ; B8CE 9D 18 30                 ..0
        sta     screen_ram+3840,x               ; B8D1 9D 18 31                 ..1
        sta     screen_ram+4096,x               ; B8D4 9D 18 32                 ..2
        sta     screen_ram+4352,x               ; B8D7 9D 18 33                 ..3
        sta     screen_ram+4608,x               ; B8DA 9D 18 34                 ..4
        sta     screen_ram+4864,x               ; B8DD 9D 18 35                 ..5
        sta     screen_ram+5120,x               ; B8E0 9D 18 36                 ..6
        sta     screen_ram+5376,x               ; B8E3 9D 18 37                 ..7
        sta     screen_ram+5632,x               ; B8E6 9D 18 38                 ..8
        sta     screen_ram+5888,x               ; B8E9 9D 18 39                 ..9
        sta     screen_ram+6144,x               ; B8EC 9D 18 3A                 ..:
        sta     screen_ram+6400,x               ; B8EF 9D 18 3B                 ..;
        sta     screen_ram+6656,x               ; B8F2 9D 18 3C                 ..<
        sta     screen_ram+6912,x               ; B8F5 9D 18 3D                 ..=
        sta     screen_ram+7168,x               ; B8F8 9D 18 3E                 ..>
        sta     screen_ram+7424,x               ; B8FB 9D 18 3F                 ..?
        inx                                     ; B8FE E8                       .
        bne     LB8A4                           ; B8FF D0 A3                    ..
        rts                                     ; B901 60                       `

; ----------------------------------------------------------------------------
init_screen_ptrs:
        lda     #$18                            ; B902 A9 18                    ..
        sta     tmp_ptr                         ; B904 85 E7                    ..
        lda     #$22                            ; B906 A9 22                    ."
        sta     tmp_ptr+1                       ; B908 85 E8                    ..
        ldx     #$C0                            ; B90A A2 C0                    ..
        ldy     #$00                            ; B90C A0 00                    ..
_isp_loop:
        lda     tmp_ptr                         ; B90E A5 E7                    ..
        sta     screen_lo_ptrs,y                ; B910 99 00 1D                 ...
        lda     tmp_ptr+1                       ; B913 A5 E8                    ..
        sta     screen_hi_ptrs,y                ; B915 99 00 1E                 ...
        clc                                     ; B918 18                       .
        lda     tmp_ptr                         ; B919 A5 E7                    ..
        adc     #$28                            ; B91B 69 28                    i(
        sta     tmp_ptr                         ; B91D 85 E7                    ..
        lda     tmp_ptr+1                       ; B91F A5 E8                    ..
        adc     #$00                            ; B921 69 00                    i.
        sta     tmp_ptr+1                       ; B923 85 E8                    ..
        iny                                     ; B925 C8                       .
        dex                                     ; B926 CA                       .
        bne     _isp_loop                       ; B927 D0 E5                    ..
LB929:  lda     #$E0                            ; B929 A9 E0                    ..
        sta     screen_lo_ptrs,y                ; B92B 99 00 1D                 ...
        sta     screen_hi_ptrs,y                ; B92E 99 00 1E                 ...
        iny                                     ; B931 C8                       .
        bne     LB929                           ; B932 D0 F5                    ..
        ldy     #$00                            ; B934 A0 00                    ..
        tya                                     ; B936 98                       .
; fill $1a00-$1aff with repeating pattern 00 01 02 03 ...
fill_offset_index_table:
        sta     offset_index_table,y            ; B937 99 00 1A                 ...
        clc                                     ; B93A 18                       .
        adc     #$01                            ; B93B 69 01                    i.
        cmp     #$04                            ; B93D C9 04                    ..
        bcc     LB943                           ; B93F 90 02                    ..
        lda     #$00                            ; B941 A9 00                    ..
LB943:  iny                                     ; B943 C8                       .
        bne     fill_offset_index_table         ; B944 D0 F1                    ..
        ldy     #$00                            ; B946 A0 00                    ..
        lda     #$C0                            ; B948 A9 C0                    ..
fill_pixel_mask_table:
        sta     pixel_mask_table,y              ; B94A 99 00 1C                 ...
        lsr     a                               ; B94D 4A                       J
        lsr     a                               ; B94E 4A                       J
        bne     LB953                           ; B94F D0 02                    ..
        lda     #$C0                            ; B951 A9 C0                    ..
LB953:  iny                                     ; B953 C8                       .
        bne     fill_pixel_mask_table           ; B954 D0 F4                    ..
        ldy     #$00                            ; B956 A0 00                    ..
        lda     #$00                            ; B958 A9 00                    ..
; fill horizontal offset table (if that's what it really is): 00 00 00 00 01 01 01 01 ... to 27 27 27 27, which repeats to the end of the page
fill_hoffset_table:
        ldx     #$04                            ; B95A A2 04                    ..
LB95C:  sta     horiz_offset_table,y            ; B95C 99 00 1B                 ...
        iny                                     ; B95F C8                       .
        beq     LB96C                           ; B960 F0 0A                    ..
        dex                                     ; B962 CA                       .
        bne     LB95C                           ; B963 D0 F7                    ..
        clc                                     ; B965 18                       .
        adc     #$01                            ; B966 69 01                    i.
        cpy     #$00                            ; B968 C0 00                    ..
        bne     fill_hoffset_table              ; B96A D0 EE                    ..
LB96C:  ldy     #$00                            ; B96C A0 00                    ..
LB96E:  lda     horiz_offset_table,y            ; B96E B9 00 1B                 ...
        cmp     #$28                            ; B971 C9 28                    .(
        bcc     LB97A                           ; B973 90 05                    ..
        lda     #$27                            ; B975 A9 27                    .'
        sta     horiz_offset_table,y            ; B977 99 00 1B                 ...
LB97A:  iny                                     ; B97A C8                       .
        bne     LB96E                           ; B97B D0 F1                    ..
; create display list at dlist_ram
setup_display_list:
        lda     #$70                            ; B97D A9 70                    .p
        sta     dlist_ram                       ; B97F 8D 00 20                 .. 
        sta     dlist_ram+1                     ; B982 8D 01 20                 .. 
        sta     dlist_ram+2                     ; B985 8D 02 20                 .. 
        lda     #$4E                            ; B988 A9 4E                    .N
        sta     dlist_ram+3                     ; B98A 8D 03 20                 .. 
        lda     #$18                            ; B98D A9 18                    ..
        sta     dlist_ram+4                     ; B98F 8D 04 20                 .. 
        lda     #$22                            ; B992 A9 22                    ."
        sta     dlist_ram+5                     ; B994 8D 05 20                 .. 
        ldy     #$58                            ; B997 A0 58                    .X
        ldx     #$00                            ; B999 A2 00                    ..
LB99B:  lda     #$0E                            ; B99B A9 0E                    ..
        cpx     #$00                            ; B99D E0 00                    ..
        bne     LB9A3                           ; B99F D0 02                    ..
        ora     #$80                            ; B9A1 09 80                    ..
LB9A3:  sta     dlist_ram+6,x                   ; B9A3 9D 06 20                 .. 
        inx                                     ; B9A6 E8                       .
        dey                                     ; B9A7 88                       .
        bne     LB99B                           ; B9A8 D0 F1                    ..
        lda     #$4E                            ; B9AA A9 4E                    .N
        sta     dlist_ram+6,x                   ; B9AC 9D 06 20                 .. 
        lda     #$00                            ; B9AF A9 00                    ..
        sta     dlist_ram+7,x                   ; B9B1 9D 07 20                 .. 
        lda     #$30                            ; B9B4 A9 30                    .0
        sta     dlist_ram+8,x                   ; B9B6 9D 08 20                 .. 
        ldy     #$65                            ; B9B9 A0 65                    .e
LB9BB:  lda     #$0E                            ; B9BB A9 0E                    ..
        sta     dlist_ram+9,x                   ; B9BD 9D 09 20                 .. 
        inx                                     ; B9C0 E8                       .
        dey                                     ; B9C1 88                       .
        bne     LB9BB                           ; B9C2 D0 F7                    ..
        lda     #$8E                            ; B9C4 A9 8E                    ..
        sta     dlist_ram+8,x                   ; B9C6 9D 08 20                 .. 
        lda     #$41                            ; B9C9 A9 41                    .A
        sta     dlist_ram+9,x                   ; B9CB 9D 09 20                 .. 
        lda     #$00                            ; B9CE A9 00                    ..
        sta     dlist_ram+10,x                  ; B9D0 9D 0A 20                 .. 
        lda     #$20                            ; B9D3 A9 20                    . 
        sta     dlist_ram+11,x                  ; B9D5 9D 0B 20                 .. 
setup_vectors:
        lda     #$46                            ; B9D8 A9 46                    .F
        sta     VDSLST                          ; B9DA 8D 00 02                 ...
        lda     #$BA                            ; B9DD A9 BA                    ..
        sta     VDSLST+1                        ; B9DF 8D 01 02                 ...
        lda     #$6D                            ; B9E2 A9 6D                    .m
        sta     VKEYBD                          ; B9E4 8D 08 02                 ...
        lda     #$BA                            ; B9E7 A9 BA                    ..
        sta     VKEYBD_hi                       ; B9E9 8D 09 02                 ...
        lda     #$00                            ; B9EC A9 00                    ..
        sta     spacebar_flag                   ; B9EE 85 AC                    ..
        sta     hyperspace_flag                 ; B9F0 85 AE                    ..
        sta     pause_flag                      ; B9F2 85 AF                    ..
        sta     select_flag                     ; B9F4 85 B0                    ..
        lda     #$00                            ; B9F6 A9 00                    ..
        sta     SDLSTL                          ; B9F8 8D 30 02                 .0.
        lda     #$20                            ; B9FB A9 20                    . 
        sta     SDLSTH                          ; B9FD 8D 31 02                 .1.
        lda     #$22                            ; BA00 A9 22                    ."
        sta     DMACTL                          ; BA02 8D 00 D4                 ...
        sta     SDMCTL                          ; BA05 8D 2F 02                 ./.
        lda     #$00                            ; BA08 A9 00                    ..
        sta     COLOR4                          ; BA0A 8D C8 02                 ...
        lda     #$CA                            ; BA0D A9 CA                    ..
        sta     COLOR0                          ; BA0F 8D C4 02                 ...
        lda     #$38                            ; BA12 A9 38                    .8
        sta     COLOR1                          ; BA14 8D C5 02                 ...
        lda     #$7E                            ; BA17 A9 7E                    .~
        sta     COLOR2                          ; BA19 8D C6 02                 ...
        lda     #$04                            ; BA1C A9 04                    ..
        sta     PACTL                           ; BA1E 8D 02 D3                 ...
        lda     #$03                            ; BA21 A9 03                    ..
        sta     SKCTL                           ; BA23 8D 0F D2                 ...
        lda     #$00                            ; BA26 A9 00                    ..
        sta     GRACTL                          ; BA28 8D 1D D0                 ...
        sta     AUDCTL                          ; BA2B 8D 08 D2                 ...
        lda     #$01                            ; BA2E A9 01                    ..
        sta     PRIOR                           ; BA30 8D 1B D0                 ...
        lda     #$04                            ; BA33 A9 04                    ..
        sta     CONSOL                          ; BA35 8D 1F D0                 ...
        lda     #$C0                            ; BA38 A9 C0                    ..
        sta     POKMSK                          ; BA3A 85 10                    ..
        sta     IRQEN                           ; BA3C 8D 0E D2                 ...
        lda     #$C0                            ; BA3F A9 C0                    ..
        sta     NMIEN                           ; BA41 8D 0E D4                 ...
        cli                                     ; BA44 58                       X
        rts                                     ; BA45 60                       `

; ----------------------------------------------------------------------------
; stuffed into VDSLST in setup_vectors
dli_handler:
        pha                                     ; BA46 48                       H
        lda     VCOUNT                          ; BA47 AD 0B D4                 ...
        cmp     #$64                            ; BA4A C9 64                    .d
        bcc     top_dli_handler                 ; BA4C 90 0B                    ..
; handle 2nd DLI (VCOUNT == $6F)
bottom_dli_handler:
        sec                                     ; BA4E 38                       8
        ror     draw_ok_flag                    ; BA4F 66 AB                    f.
        lda     key_debounce_ctr                ; BA51 A5 F0                    ..
        bmi     LBA57                           ; BA53 30 02                    0.
        inc     key_debounce_ctr                ; BA55 E6 F0                    ..
LBA57:  pla                                     ; BA57 68                       h
        rti                                     ; BA58 40                       @

; ----------------------------------------------------------------------------
; handle first DLI (VCOUNT == $10)
top_dli_handler:
        lsr     draw_ok_flag                    ; BA59 46 AB                    F.
        txa                                     ; BA5B 8A                       .
        pha                                     ; BA5C 48                       H
        tya                                     ; BA5D 98                       .
        pha                                     ; BA5E 48                       H
        jsr     update_sound                    ; BA5F 20 27 8D                  '.
        pla                                     ; BA62 68                       h
        tay                                     ; BA63 A8                       .
        pla                                     ; BA64 68                       h
        tax                                     ; BA65 AA                       .
        pla                                     ; BA66 68                       h
        rti                                     ; BA67 40                       @

; ----------------------------------------------------------------------------
        sec                                     ; BA68 38                       8
        ror     spacebar_flag                   ; BA69 66 AC                    f.
        pla                                     ; BA6B 68                       h
        rti                                     ; BA6C 40                       @

; ----------------------------------------------------------------------------
; stuffed into VKEYBD in setup_vectors
vkeybd_handler:
        lda     key_debounce_ctr                ; BA6D A5 F0                    ..
        cmp     #$10                            ; BA6F C9 10                    ..
        bcs     check_key_code                  ; BA71 B0 03                    ..
        jmp     vkeybd_finish                   ; BA73 4C 98 BA                 L..

; ----------------------------------------------------------------------------
; keypress is debounced, see which key was hit
check_key_code:
        lda     KBCODE                          ; BA76 AD 09 D2                 ...
        sta     last_kbcode                     ; BA79 85 E0                    ..
        cmp     #$1C                            ; BA7B C9 1C                    ..
        beq     esc_pressed                     ; BA7D F0 10                    ..
        cmp     #$21                            ; BA7F C9 21                    .!
        beq     space_pressed                   ; BA81 F0 06                    ..
; neither space nor esc was pressed. either some other key, or no key ($ff)
other_key_pressed:
        sec                                     ; BA83 38                       8
        ror     hyperspace_flag                 ; BA84 66 AE                    f.
        jmp     vkeybd_finish                   ; BA86 4C 98 BA                 L..

; ----------------------------------------------------------------------------
; detonate smart bomb if any left, when game is playing
space_pressed:
        sec                                     ; BA89 38                       8
        ror     spacebar_flag                   ; BA8A 66 AC                    f.
        jmp     vkeybd_finish                   ; BA8C 4C 98 BA                 L..

; ----------------------------------------------------------------------------
; toggle pause mode, when game is playing
esc_pressed:
        lda     pause_flag                      ; BA8F A5 AF                    ..
        eor     #$80                            ; BA91 49 80                    I.
        sta     pause_flag                      ; BA93 85 AF                    ..
        jmp     vkeybd_finish                   ; BA95 4C 98 BA                 L..

; ----------------------------------------------------------------------------
; reset debounce counter and exit
vkeybd_finish:
        lda     #$00                            ; BA98 A9 00                    ..
        sta     key_debounce_ctr                ; BA9A 85 F0                    ..
        sta     ATRACT                          ; BA9C 85 4D                    .M
        pla                                     ; BA9E 68                       h
        rti                                     ; BA9F 40                       @

; ----------------------------------------------------------------------------
; see if start or select are pressed, set flags
read_consol:
        lda     #$08                            ; BAA0 A9 08                    ..
        sta     CONSOL                          ; BAA2 8D 1F D0                 ...
        lda     CONSOL                          ; BAA5 AD 1F D0                 ...
        and     #$07                            ; BAA8 29 07                    ).
        eor     #$07                            ; BAAA 49 07                    I.
        cmp     #$01                            ; BAAC C9 01                    ..
        beq     start_pressed                   ; BAAE F0 16                    ..
        cmp     #$02                            ; BAB0 C9 02                    ..
        beq     select_pressed                  ; BAB2 F0 01                    ..
; several code paths jump here instead of doing their own RTS
consol_done:
        rts                                     ; BAB4 60                       `

; ----------------------------------------------------------------------------
; user pressed select key, ignore if game is playing & not paused
select_pressed:
        bit     pause_flag                      ; BAB5 24 AF                    $.
        bmi     handle_select                   ; BAB7 30 03                    0.
        jmp     consol_done                     ; BAB9 4C B4 BA                 L..

; ----------------------------------------------------------------------------
handle_select:
        sec                                     ; BABC 38                       8
        ror     select_flag                     ; BABD 66 B0                    f.
        lda     #$00                            ; BABF A9 00                    ..
        sta     ATRACT                          ; BAC1 85 4D                    .M
        jmp     consol_done                     ; BAC3 4C B4 BA                 L..

; ----------------------------------------------------------------------------
; user pressed start key, ignore if game is playing & not paused
start_pressed:
        bit     pause_flag                      ; BAC6 24 AF                    $.
        bpl     ignore_start                    ; BAC8 10 07                    ..
        sec                                     ; BACA 38                       8
        ror     start_flag                      ; BACB 66 BE                    f.
        lda     #$00                            ; BACD A9 00                    ..
        sta     ATRACT                          ; BACF 85 4D                    .M
; don't handle start key while game is playing & not paused
ignore_start:
        jmp     consol_done                     ; BAD1 4C B4 BA                 L..

; ----------------------------------------------------------------------------
spawn_baiter:
        lda     sprite_y                        ; BAD4 A5 DF                    ..
        cmp     ship_y_pos                      ; BAD6 C5 C4                    ..
        bcs     LBADF                           ; BAD8 B0 05                    ..
        inc     sprite_y                        ; BADA E6 DF                    ..
        jmp     LBAE1                           ; BADC 4C E1 BA                 L..

; ----------------------------------------------------------------------------
LBADF:  dec     sprite_y                        ; BADF C6 DF                    ..
LBAE1:  lda     ship_delta                      ; BAE1 A5 D5                    ..
        bpl     LBAEA                           ; BAE3 10 05                    ..
        eor     #$FF                            ; BAE5 49 FF                    I.
        clc                                     ; BAE7 18                       .
        adc     #$01                            ; BAE8 69 01                    i.
LBAEA:  clc                                     ; BAEA 18                       .
        adc     #$02                            ; BAEB 69 02                    i.
        sta     $E5                             ; BAED 85 E5                    ..
        sec                                     ; BAEF 38                       8
        lda     $91                             ; BAF0 A5 91                    ..
        sbc     $DD                             ; BAF2 E5 DD                    ..
        sta     sprite_x                        ; BAF4 85 E3                    ..
        lda     $92                             ; BAF6 A5 92                    ..
        sbc     $DE                             ; BAF8 E5 DE                    ..
        sta     $E4                             ; BAFA 85 E4                    ..
        bcs     LBB10                           ; BAFC B0 12                    ..
        lda     sprite_x                        ; BAFE A5 E3                    ..
        eor     #$FF                            ; BB00 49 FF                    I.
        sta     sprite_x                        ; BB02 85 E3                    ..
        lda     $E4                             ; BB04 A5 E4                    ..
        eor     #$FF                            ; BB06 49 FF                    I.
        sta     $E4                             ; BB08 85 E4                    ..
        inc     sprite_x                        ; BB0A E6 E3                    ..
        bne     LBB10                           ; BB0C D0 02                    ..
        inc     $E4                             ; BB0E E6 E4                    ..
LBB10:  lda     $E4                             ; BB10 A5 E4                    ..
        bne     LBB28                           ; BB12 D0 14                    ..
        lda     sprite_x                        ; BB14 A5 E3                    ..
        cmp     #$20                            ; BB16 C9 20                    . 
        bcs     LBB28                           ; BB18 B0 0E                    ..
        ldy     $98                             ; BB1A A4 98                    ..
        lda     sprite_list+128,y               ; BB1C B9 6B 0B                 .k.
        sta     $E5                             ; BB1F 85 E5                    ..
        lda     sprite_list+129,y               ; BB21 B9 6C 0B                 .l.
        bpl     LBB4E                           ; BB24 10 28                    .(
        bmi     LBB32                           ; BB26 30 0A                    0.
LBB28:  lda     $DD                             ; BB28 A5 DD                    ..
        cmp     $91                             ; BB2A C5 91                    ..
        lda     $DE                             ; BB2C A5 DE                    ..
        sbc     $92                             ; BB2E E5 92                    ..
        bcc     LBB4E                           ; BB30 90 1C                    ..
LBB32:  sec                                     ; BB32 38                       8
        lda     $DD                             ; BB33 A5 DD                    ..
        sbc     $E5                             ; BB35 E5 E5                    ..
        sta     $DD                             ; BB37 85 DD                    ..
        lda     $DE                             ; BB39 A5 DE                    ..
        sbc     #$00                            ; BB3B E9 00                    ..
        sta     $DE                             ; BB3D 85 DE                    ..
        ldy     $98                             ; BB3F A4 98                    ..
        lda     $E5                             ; BB41 A5 E5                    ..
        sta     sprite_list+128,y               ; BB43 99 6B 0B                 .k.
        lda     #$FF                            ; BB46 A9 FF                    ..
        sta     sprite_list+129,y               ; BB48 99 6C 0B                 .l.
        jmp     LBB65                           ; BB4B 4C 65 BB                 Le.

; ----------------------------------------------------------------------------
LBB4E:  clc                                     ; BB4E 18                       .
        lda     $E5                             ; BB4F A5 E5                    ..
        adc     $DD                             ; BB51 65 DD                    e.
        sta     $DD                             ; BB53 85 DD                    ..
        lda     $DE                             ; BB55 A5 DE                    ..
        adc     #$00                            ; BB57 69 00                    i.
        sta     $DE                             ; BB59 85 DE                    ..
        ldy     $98                             ; BB5B A4 98                    ..
        lda     $E5                             ; BB5D A5 E5                    ..
        sta     sprite_list+128,y               ; BB5F 99 6B 0B                 .k.
        sta     sprite_list+129,y               ; BB62 99 6C 0B                 .l.
LBB65:  lda     #$03                            ; BB65 A9 03                    ..
        sta     $94                             ; BB67 85 94                    ..
        lda     animation_counter               ; BB69 A5 85                    ..
        adc     #$0C                            ; BB6B 69 0C                    i.
        and     #$07                            ; BB6D 29 07                    ).
        bne     LBB74                           ; BB6F D0 03                    ..
        jsr     L9A9C                           ; BB71 20 9C 9A                  ..
LBB74:  lda     #$18                            ; BB74 A9 18                    ..
        sta     $88                             ; BB76 85 88                    ..
        jmp     LA5B2                           ; BB78 4C B2 A5                 L..

; ----------------------------------------------------------------------------
; decide whether to spawn a baiter
baiter_check:
        lda     level_jiffies_hi                ; BB7B A5 F6                    ..
        beq     bc_done                         ; BB7D F0 23                    .#
        cmp     #$02                            ; BB7F C9 02                    ..
        bcs     bc_spawn                        ; BB81 B0 0A                    ..
        lda     enemy_count                     ; BB83 A5 9C                    ..
        ora     landers_to_spawn                ; BB85 05 9B                    ..
        ora     baiter_count                    ; BB87 05 9D                    ..
        cmp     #$04                            ; BB89 C9 04                    ..
        bcs     bc_done                         ; BB8B B0 15                    ..
; yes, spawn it
bc_spawn:
        jsr     get_spawn_pos                   ; BB8D 20 0C 8D                  ..
        lda     $91                             ; BB90 A5 91                    ..
        sta     $DD                             ; BB92 85 DD                    ..
        lda     $92                             ; BB94 A5 92                    ..
        sta     $DE                             ; BB96 85 DE                    ..
        lda     #$07                            ; BB98 A9 07                    ..
        sta     current_sprite                  ; BB9A 85 F9                    ..
        jsr     spawn_sprite                    ; BB9C 20 ED AB                  ..
        jsr     play_materialize                ; BB9F 20 32 8E                  2.
bc_done:rts                                     ; BBA2 60                       `

; ----------------------------------------------------------------------------
filler_bba3:
        .byte   $00,$00,$00,$08,$00,$00,$00,$00 ; BBA3 00 00 00 08 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BBAB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$08,$00,$00,$00,$00 ; BBB3 00 00 00 08 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BBBB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$08,$00,$00,$00,$00 ; BBC3 00 00 00 08 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BBCB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$08,$00,$00,$00,$00 ; BBD3 00 00 00 08 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BBDB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$08,$00,$00,$00,$00 ; BBE3 00 00 00 08 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BBEB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$08,$00,$00,$00,$00 ; BBF3 00 00 00 08 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BBFB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC03 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC0B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC13 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC1B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC23 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC2B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC33 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC3B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC43 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC4B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC53 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC5B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC63 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC6B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC73 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC7B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC83 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC8B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC93 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BC9B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BCA3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BCAB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$10 ; BCB3 00 00 00 00 00 00 00 10  ........
        .byte   $00,$00,$00,$00,$08,$00,$00,$10 ; BCBB 00 00 00 00 08 00 00 10  ........
        .byte   $02,$08,$00,$00,$01,$00,$00,$10 ; BCC3 02 08 00 00 01 00 00 10  ........
        .byte   $00,$00,$00,$00,$09,$00,$00,$10 ; BCCB 00 00 00 00 09 00 00 10  ........
        .byte   $02,$08,$00,$00,$01,$00,$00,$10 ; BCD3 02 08 00 00 01 00 00 10  ........
        .byte   $00,$00,$00,$00,$08,$00,$00,$10 ; BCDB 00 00 00 00 08 00 00 10  ........
        .byte   $02,$08,$00,$00,$01,$00,$00,$10 ; BCE3 02 08 00 00 01 00 00 10  ........
        .byte   $00,$00,$00,$00,$08,$00,$00,$10 ; BCEB 00 00 00 00 08 00 00 10  ........
        .byte   $02,$08,$00,$00,$00,$00,$00,$10 ; BCF3 02 08 00 00 00 00 00 10  ........
        .byte   $00,$00,$00,$00,$08,$00,$01,$00 ; BCFB 00 00 00 00 08 00 01 00  ........
        .byte   $00,$00,$01,$00,$01,$00,$00,$00 ; BD03 00 00 01 00 01 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$01,$00 ; BD0B 00 00 00 00 00 00 01 00  ........
        .byte   $00,$00,$01,$00,$01,$00,$00,$00 ; BD13 00 00 01 00 01 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD1B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD23 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD2B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD33 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD3B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD43 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD4B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD53 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD5B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD63 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD6B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD73 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD7B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD83 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD8B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD93 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BD9B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDA3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDAB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDB3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDBB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDC3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDCB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDD3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDDB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDE3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDEB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDF3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BDFB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE03 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE0B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE13 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE1B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE23 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE2B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE33 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE3B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE43 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE4B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE53 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE5B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE63 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE6B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE73 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE7B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE83 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE8B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE93 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BE9B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BEA3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BEAB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BEB3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BEBB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BEC3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BECB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BED3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BEDB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BEE3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BEEB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BEF3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BEFB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF03 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF0B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF13 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF1B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF23 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF2B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF33 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF3B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF43 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF4B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF53 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF5B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF63 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF6B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF73 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF7B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF83 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF8B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF93 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BF9B 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BFA3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BFAB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BFB3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BFBB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BFC3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BFCB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BFD3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BFDB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BFE3 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$00,$00,$00 ; BFEB 00 00 00 00 00 00 00 00  ........
        .byte   $00,$00,$00,$00,$00,$FF,$00     ; BFF3 00 00 00 00 00 FF 00     .......
; ----------------------------------------------------------------------------
cart_a_start:
        .addr   init_cart                       ; BFFA 00 80                    ..
; ----------------------------------------------------------------------------
; 0 = cart present
cart_a_present:
        .byte   $00                             ; BFFC 00                       .
; no disk boot, yes init+start the cart, non-diagnostic
cart_a_opts:
        .byte   $04                             ; BFFD 04                       .
; ----------------------------------------------------------------------------
cart_a_init:
        .addr   init_cart                       ; BFFE 00 80                    ..