mirror of https://github.com/stella-emu/stella.git
119 lines
1.1 KiB
NASM
119 lines
1.1 KiB
NASM
;;A Bankswitcing demo for TigerVision's 3F scheme. 4 2K slices
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;;By Rick Skrbina 5/4/09
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TIA_BASE_ADDRESS = $40 ;Use $40-$7F for TIA access so there is no undesired Bankswitch
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processor 6502
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include "vcs.h"
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include "macro.h"
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seg.u vars
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org $80
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seg slice0
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org $0000
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rorg $F000
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Slice0
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lda #$1F
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sta COLUBK
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rts
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seg slice1
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org $0800
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rorg $F000
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Slice1
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lda #$2F
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sta COLUBK
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rts
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seg slice2
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org $1000
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rorg $F000
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Slice2
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lda #$3F
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sta COLUBK
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rts
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seg slice3
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org $1800
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rorg $F800
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Slice3
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CLEAN_START
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Start_Frame
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lda #2
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sta VBLANK
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sta VSYNC
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sta WSYNC
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sta WSYNC
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sta WSYNC
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lsr
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sta VSYNC
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ldy #37
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VerticalBlank
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sta WSYNC
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dey
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bne VerticalBlank
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lda #0
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sta VBLANK
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lda #$0F
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sta COLUBK
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ldy #48
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Picture0
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sta WSYNC
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dey
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bne Picture0
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lda #0
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sta $3F
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jsr Slice0
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ldy #48
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Picture1
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sta WSYNC
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dey
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bne Picture1
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lda #1
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sta $3F
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jsr Slice1
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ldy #48
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Picture2
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sta WSYNC
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dey
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bne Picture2
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lda #2
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sta $3F
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jsr Slice2
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ldy #48
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Picture3
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sta WSYNC
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dey
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bne Picture3
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lda #2
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sta VBLANK
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ldy #30
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OverScan
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sta WSYNC
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dey
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bne OverScan
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jmp Start_Frame
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org $1FFC
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rorg $FFFC
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.word Slice3
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.byte "RS"
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