mirror of https://github.com/a2-4am/4cade.git
62 lines
1.4 KiB
Plaintext
62 lines
1.4 KiB
Plaintext
;license:MIT
|
|
;(c) 2021 by 4am
|
|
|
|
!cpu 6502
|
|
!to "build/FX.INDEXED/SHR.UD",plain
|
|
*=$A000
|
|
|
|
!source "src/fx/fx.shr.common.a"
|
|
|
|
shrlo = $301 ; $C8 bytes
|
|
shrhi = $38 ; $C8 bytes
|
|
reverseshrlo = $BD01 ; $C8 bytes
|
|
reverseshrhi = $BE01 ; $C8 bytes
|
|
|
|
ldx #(end-start-1) ; copy loop to zero page
|
|
- lda start, x
|
|
sta $00, x
|
|
dex
|
|
bpl -
|
|
|
|
+BUILD_SHR_REVERSE_LOOKUP_TABLES reverseshrlo, reverseshrhi
|
|
+BUILD_SHR_LOOKUP_TABLES shrlo, shrhi
|
|
;X=0
|
|
+COPY_SCB_AND_PALETTES
|
|
;WRITEAUXMEM active
|
|
|
|
ldx #$C8
|
|
jmp loop
|
|
|
|
start
|
|
!pseudopc 0 {
|
|
loop lda shrlo-1, x
|
|
sta <dst+1
|
|
lda shrhi-1, x
|
|
sta <dst+2
|
|
lda reverseshrlo-1, x
|
|
sta <rdst+1
|
|
lda reverseshrhi-1, x
|
|
sta <rdst+2
|
|
ldy #$00
|
|
loop2 lda (<dst+1), y
|
|
dst sta $0000, y ; SMC
|
|
iny
|
|
lda (<rdst+1), y
|
|
rdst sta $0000, y ; SMC
|
|
iny
|
|
cpy #$A0
|
|
bcc loop2
|
|
lda $C000
|
|
bmi exit
|
|
dex
|
|
bne loop
|
|
exit
|
|
rts
|
|
}
|
|
end
|
|
|
|
; if zero page code gets too large, move shrhi to $201
|
|
!if end-start > $38 {
|
|
!error "code is too large: ends at ", end-start
|
|
}
|