diff options
| -rw-r--r-- | bigint48.s | 6 | ||||
| -rw-r--r-- | cartname_5200.s | 14 | ||||
| -rw-r--r-- | cartyear_5200.s | 11 | ||||
| -rw-r--r-- | crt0_5200.s | 183 | ||||
| -rw-r--r-- | hello52.c | 20 |
5 files changed, 232 insertions, 2 deletions
@@ -3,8 +3,10 @@ ; the Atari 800/XL/XE build doesn't use this, it's only for ; the 5200 (though the A8 build can be tested with it). -; .include "atari.inc" ; don't include atari.inc on the 5200, I'll get confused. - FR0 = $d4 ; this is the only label we need from atari.inc +; .include "atari.inc" ; don't include atari.inc on the 5200, + ; I'll get confused even if ca65 doesn't. + FR0 = $d4 ; this is the only label we need from atari.inc. on + ; the 5200, $d4 and up are free zero page. .export _big_copy, _ulong_to_big, _big_cmp, _big_to_ulong, _big_add, _big_sub, _big_negate .export _big_div, _big_mul diff --git a/cartname_5200.s b/cartname_5200.s new file mode 100644 index 0000000..412afaa --- /dev/null +++ b/cartname_5200.s @@ -0,0 +1,14 @@ +; default cartridge name +; +; Christian Groessler, 01-Mar-2014 +; modified for taipan + +; anything in CAPS will rotate colors + +.include "atari.mac" + +.export __CART_NAME__: absolute = 1 + +.segment "CARTNAME" + + scrcode " taipan ALPHA " diff --git a/cartyear_5200.s b/cartyear_5200.s new file mode 100644 index 0000000..e5f1b40 --- /dev/null +++ b/cartyear_5200.s @@ -0,0 +1,11 @@ +; Cartridge copyright year +; +; Christian Groessler, 01-Mar-2014 + +; modified for taipan + +.export __CART_YEAR__: absolute = 1 + +.segment "CARTYEAR" + + .byte $ff, $ff ; $ff in 2nd byte means diagnostic cart diff --git a/crt0_5200.s b/crt0_5200.s new file mode 100644 index 0000000..5210ec1 --- /dev/null +++ b/crt0_5200.s @@ -0,0 +1,183 @@ +; +; Startup code for cc65 (Atari5200 version) +; +; Christian Groessler (chris@groessler.org), 2014 + +; modified for taipan, to work as a diagnostic cart. +; contains code adapted from the 5200 OS ROM. + + .export _exit, start + .export __STARTUP__ : absolute = 1 ; Mark as startup + .import __RAM_START__, __RAM_SIZE__ + .import __RESERVED_MEMORY__ + + .import initlib, donelib, callmain + .import zerobss, copydata + + .include "zeropage.inc" + .include "atari5200.inc" + +;;; start of (slightly modified) OS ROM code. the OS calls us with +;;; interrupts disabled, decimal mode cleared, with the stack pointer +;;; set to $FF. Since this is a diagnostic cart, we have to init the +;;; hardware and set up the interrupt vector table at $0200 (the OS +;;; doesn't do it for us, like it would for a non-diag cart). + +;;; This code is based on Dan Boris's commented disassembly of the 4-port +;;; 5200 BIOS, retrieved from <http://atarihq.com/danb/files/5200BIOS.txt>. + +;;; I've copied just the initialization code, minus the logo/copyright +;;; screen, and modified it to work with either OS revision. + +;;; Everything I've read tells me that the 4-port OS will work on a 2-port +;;; machine (the hardware changes don't break compatibility), so the code +;;; here comes from the 4-port OS. + +; I've gone to a lot of trouble to get the vectors and display list +; set up correctly for either ROM revision... but the display list, at +; least, was really a waste of time: conio is going to set up a GR.1 +; display list... at least until I modify it to use GR.0 instead. + +start: + ldx #0 + txa +@clrloop: + sta POKEY,x ;Clear POKEY registers + sta GTIA,x ;Clear GTIA registers + sta ANTIC,x ;Clear ANTIC registers + sta $00,x ;Clear zero page + inx + bne @clrloop + lda #$F8 + sta CHBASE ;Set Character base to $F800 + +; determine which OS revision we're running under. This affects +; the locations of the vector table and display list in the ROM, +; and is probably the reason a few published 5200 games are +; incompatible with the Rev A ROM. +; rev A has $07 at $fee5, original OS has $61. If there are other +; OS revisions out there in the wild, this code will likely fail +; on them. + + lda #$fe + sta $fb +; sta $fd +; sta $ff + lda $fee5 + cmp #$07 + beq @rev_a + + ; set up $fa to point to vector table, + ; $fc to point to display list start, + ; $fe to point to DL end. + + ; old OS: + lda #$95 + sta $fa +; lda #$c8 +; sta $fc +; lda #$cf +; sta $fe + bne @copy_vectors + +@rev_a: + lda #$ab + sta $fa +; lda #$de +; sta $fc +; lda #$e5 +; sta $fe + +@copy_vectors: + ldy #$0B +@cploop: + lda ($fa),y + sta VIMIRQ,y ;Copy vectors to vector table + dey + bpl @cploop + + lda #$3C ;Set pointer to $3C00 + sta $12 + lda #$00 + sta $11 + + ldx #$0C + tay +@vecloop: + sta ($11),y + dey + bne @vecloop + dec $12 + dex + bpl @vecloop + +;;; taipan doesn't need the OS-provided display list. +;;; conio init will set up a GR.1 DL (at least, until +;;; I modify it to the GR.0 that taipan needs) +;Build display list +; lda #$0D ;Antic mode 13 +; ldx #$4D +;@dl13loop: +; sta $2007,x ;write to display list +; dex +; bpl @dl13loop +; +; ldy #$06 ;Copy start of display list +;@dlloop: +; lda ($fc),y +; sta $2000,y +; dey +; bpl @dlloop +; +; ldy #$04 ;Copy end of display list +;@dlendloop: +; lda ($fe),y +; sta $2055,y +; dey +; bpl @dlendloop +; +; lda #$00 ;Set Display List pointer to $2000 +; sta $05 +; lda #$20 +; sta $06 + + lda #$22 ;Set DMACTL, dlist on/normal background + sta SDMCTL + + lda #$C0 + sta NMIEN ;Enable DLI and VBI + lda #$02 + sta SKCTL ;Enable Keyboard scanning + + .out .sprintf("%d bytes", * - start) +;;; end of OS ROM code, rest of file is standard 5200 crt0.s. + +; Clear the BSS data. + + jsr zerobss + +; Initialize the data. + jsr copydata + +; Set up the stack. + + lda #<(__RAM_START__ + __RAM_SIZE__ - __RESERVED_MEMORY__) + sta sp + lda #>(__RAM_START__ + __RAM_SIZE__ - __RESERVED_MEMORY__) + sta sp+1 ; Set argument stack ptr + +; Call the module constructors. + + jsr initlib + +; Push the command-line arguments; and, call main(). + + jsr callmain + +; Call the module destructors. This is also the exit() entry. + +_exit: jsr donelib ; Run module destructors + +; A 5200 program isn't supposed to exit. + +halt: jmp halt diff --git a/hello52.c b/hello52.c new file mode 100644 index 0000000..eba835d --- /dev/null +++ b/hello52.c @@ -0,0 +1,20 @@ +/* + build as a 32K diagnostic cart: + cl65 -m hello52.map -t atari5200 -Wl -D__CARTSIZE__=0x8000 -o 1.bin hello52.c cartname_5200.s cartyear_5200.s crt0_5200.s + + run with original OS: + atari800 -5200 -cart-type 4 -cart 1.bin + + or run with rev A: + atari800 -5200 -5200-rev a -cart-type 4 -cart 1.bin + +*/ + +#include <conio.h> + +int main(void) { + gotoxy(5, 11); + cputs("HELLO WORLD"); +hang: goto hang; + return 0; +} |