mirror of https://github.com/a2-4am/4cade.git
54 lines
1.1 KiB
Plaintext
54 lines
1.1 KiB
Plaintext
;license:MIT
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;(c) 2021 by 4am
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!cpu 6502
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!to "build/FX.INDEXED/SHR.TWOPASS.LR",plain
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*=$A000
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!source "src/fx/fx.shr.common.a"
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shrlo = $301 ; $C8 bytes
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shrhi = $38 ; $C8 bytes
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ldx #(end-start-1) ; copy loop to zero page
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- lda start, x
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sta $00, x
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dex
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bpl -
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+BUILD_SHR_LOOKUP_TABLES shrlo, shrhi
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+COPY_SCB_AND_PALETTES
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jmp loop1
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start
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!pseudopc 0 {
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loop1 ldy #0
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loop2 ldx #1
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loop3 lda shrlo-1, x
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sta <dst+1
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lda shrhi-1, x
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sta <dst+2
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lda (<dst+1), y
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dst sta $0000, y ; SMC
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inx
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inx
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cpx #$C8
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bcc loop3
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lda $C000
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bmi @exit
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iny
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cpy #$A0
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bne loop2
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dec <loop2+1
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bpl loop1
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@exit sta $C004
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rts
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}
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end
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; if zero page code gets too large, move shrhi to $201
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!if end-start > $38 {
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!error "code is too large: ends at ", end-start
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}
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