8bitworkshop/presets/atari8-5200/hello.dasm

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; Atari 5200 "Hello World" sample code
; Written by Daniel Boris (danlb_2000@yahoo.com)
;
; Assemble with DASM
;
processor 6502
include "atari5200.inc"
org $4000 ;Start of cartridge area
sei ;Disable interrupts
cld ;Clear decimal mode
Start
ldx #$00
lda #$00
crloop1
sta $00,x ;Clear zero page
sta $D400,x ;Clear ANTIC
sta $C000,x ;Clear GTIA
sta $E800,x ;Clear POKEY
dex
bne crloop1
ldy #$00 ;Clear Ram
lda #$02 ;Start at $0200
sta $81
lda #$00
sta $80
crloop2
lda #$00
crloop3
sta ($80),y ;Store data
iny ;Next byte
bne crloop3 ;Branch if not done page
inc $81 ;Next page
lda $81
cmp #$40 ;Check if end of RAM
bne crloop2 ;Branch if not
ldx #$2f
dlloop ;Create Display List
lda dlist,x ;Get byte
sta $1000,x ;Copy to RAM
dex ;next byte
bpl dlloop
lda #$03 ;point IRQ vector
sta $200 ;to BIOS routine
lda #$FC
sta $201
lda #$B8 ;point VBI vector
sta $202 ;to BIOS routine
lda #$FC
sta $203
lda #$B2 ;point Deferred VBI
sta $204 ;to BIOS routine
lda #$FC
sta $205
lda #$06
sta CHACTL ;Set Character Control
lda #$84 ;Set color PF2
sta COLOR0+2
sta COLOR0+4 ; bakground
lda #$0F ;Set color PF1
sta COLOR0+1
lda #$3f
sta COLOR0+0
lda #$58
sta COLOR0+3
lda #$00 ;Set Display list pointer
sta SDLSTL ;Shadow DLISTL
sta DLISTL
lda #$10
sta SDLSTH ;Shadow DLISTH
sta DLISTH
lda #$f8 ;Set Charcter Set Base
sta CHBASE
lda #$22 ;Enable DMA
sta SDMCTL ;Shadow DMACTL
lda #$40 ;Enable NMI
sta NMIEN
print
ldy #$00
cld
prloop
lda text1,y ;Get character
beq wait
cmp #$60
bcs lower
sec
sbc #$20 ;Convert to ATASCII
lower
sta $1800,y ;Store in video memory
iny ;Next character
bne prloop
wait
nop
jmp wait
;Display list data (starts at $1000)
dlist .byte $70,$70,$70 ;24 blank scanlines
.byte $42,$00,$18,$02 ;mode 2 @ $1800
.byte $43,$00,$18,$02 ;mode 3 @ $1800
.byte $44,$00,$18,$02 ;mode 4 @ $1800
.byte $45,$00,$18,$02 ;mode 5 @ $1800
.byte $46,$00,$18,$06 ;mode 6 @ $1800
.byte $47,$00,$18,$06 ;mode 7 @ $1800
.byte $41,$00,$10 ;JMP -> $1000
;Text data
org $b100
text1 .byte "Hello World! "
.byte $a1,$a2,$a3
.byte 0
org $bffd
.byte $FF ;Don't display Atari logo
.byte $00,$40 ;Start code at $4000