mirror of
https://github.com/sehugg/8bitworkshop.git
synced 2024-11-25 03:34:05 +00:00
73 lines
1.3 KiB
NASM
73 lines
1.3 KiB
NASM
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processor 6502
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include "basicheader.dasm"
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Src equ $02
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Dest equ $04
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Start:
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lda #$38 ; 25 rows, on, bitmap
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sta $d011 ; VIC control #1
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lda #$18 ; 40 column, multicolor
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sta $d016 ; VIC control #2
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lda #$02
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sta $dd00 ; set VIC bank ($4000-$7FFF)
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lda #$80
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sta $d018 ; set VIC screen to $6000
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lda XtraData+0
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sta $d020 ; border
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sta $d021 ; background
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lda #0
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sta Dest
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; copy char memory
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lda #<CharData
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sta Src
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lda #>CharData
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sta Src+1
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lda #$40
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sta Dest+1
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ldx #$20
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jsr CopyMem
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; copy screen memory
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lda #<ScreenData
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sta Src
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lda #>ScreenData
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sta Src+1
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lda #$60
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sta Dest+1
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ldx #$04
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jsr CopyMem
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; copy color RAM
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lda #<ColorData
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sta Src
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lda #>ColorData
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sta Src+1
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lda #$d8
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sta Dest+1
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ldx #4
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jsr CopyMem
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; infinite loop
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jmp .
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; copy data from Src to Dest
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; X = number of bytes * 256
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CopyMem
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ldy #0
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.Loop
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lda (Src),y
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sta (Dest),y
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iny
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bne .Loop
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inc Src+1
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inc Dest+1
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dex
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bne .Loop
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rts
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; bitmap data
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CharData equ .
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ScreenData equ CharData+8000
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ColorData equ ScreenData+1000
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XtraData equ ColorData+1000
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incbin "badspacerobots-c64.multi.bin"
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