76 lines
2.1 KiB
Plaintext
76 lines
2.1 KiB
Plaintext
; Atari "Hello World" sample code
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; Written by Daniel Boris (dboris@comcast.net)
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; Modified by Steven Hugg @8bitworkshop
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; Assemble with DASM
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processor 6502
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include "atari.inc"
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org $a000 ;Start of left cartridge area
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Start
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ldx #(dlistend-dlist)
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dlloop ;Create Display List
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lda dlist,x ;Get byte
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sta $1000,x ;Copy to RAM
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dex ;next byte
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bpl dlloop
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lda #$06
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sta CHACTL ;Set Character Control
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lda #$84 ;Set color PF2
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sta COLOR0+2
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sta COLOR0+4 ; bakground
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lda #$0F ;Set color PF1
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sta COLOR0+1
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lda #$3f
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sta COLOR0+0
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lda #$58
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sta COLOR0+3
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lda #$00 ;Set Display list pointer
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sta SDLSTL ;Shadow DLISTL
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lda #$10
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sta SDLSTH ;Shadow DLISTH
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lda #$e0 ;Set Charcter Set Base
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sta CHBAS
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lda #$22 ;Enable DMA
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sta SDMCTL ;Shadow DMACTL
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print
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ldy #$00
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cld
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prloop
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lda text1,y ;Get character
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beq wait
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cmp #$60
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bcs lower
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sec
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sbc #$20 ;Convert to ATASCII
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lower
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sta $1800,y ;Store in video memory
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iny ;Next character
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bne prloop
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wait
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nop
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jmp wait
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;Display list data (starts at $1000)
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dlist .byte $70,$70,$70 ;24 blank scanlines
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.byte $42,$00,$18,$02 ;mode 2 @ $1800
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.byte $41,$00,$10 ;JMP -> $1000
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dlistend
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;Text data
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;(will be converted to ATASCII and stored in video RAM)
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text1 .byte "Hello World! " ; ASCII text
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.byte $c0 ; ATASCII
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.byte 0
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;Cartridge footer
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org CARTCS
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.word Start ; cold start address
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.byte $00 ; 0 == cart exists
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.byte $04 ; boot cartridge
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.word Start ; start
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