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; explosion seen when we're hit by enemy fire.
; currently just flashes the screen. the apple version is
; kinda funky-looking, best way I can describe it is that it
; looks like TV static. would be hard to imitate that on the
; atari. maybe there should be screen-shaking going on?
; original code was in C, and looked like:
;; for(i = 0; i < 3; i++) {
;; unsigned char color = PEEK(710) & 0xf0;
;; unsigned char textcolor = PEEK(709);
;; POKE(709,0);
;; POKE(710, color | 0x0c);
;; jsleep(10);
;; POKE(710, color & 0xf0);
;; jsleep(10);
;; POKE(709,textcolor);
;; }
.export _explosion
.include "atari.inc"
.importzp tmp1, tmp2
.import _jsleep
iloop_count = tmp1
; extern void explosion(void);
_explosion:
; {
ldy #3 ; loop counter, counts 3 2 1
; {
@loop:
lda #$03
sta iloop_count
@iloop:
ldx #0 ; jsleep(2)
lda #$02
jsr _jsleep
ldx #2
@b:
lda VCOUNT
cmp #(4+8)*4
bne @b
@d:
sta WSYNC
lda RANDOM
lsr ; avoid reading I/O registers, I think it can lock up SDX
sta CHBASE
lda VCOUNT
cmp #(4+23)*4
bne @d
lda #$e0
sta CHBASE
lda RTCLOK+2
@c:
cmp RTCLOK+2
beq @c
dex
bne @b
dec iloop_count
bne @iloop
ldx #0 ; jsleep(10)
lda #$0a
jsr _jsleep
dey
bne @loop ; we're done if Y==0
; }
rts
; }
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