dos33fsprogs/demos/second/part20_credits/vertical_scroll.s

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294 B
ArmAsm
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2023-10-24 05:56:32 +00:00
hgr_vertical_scroll:
ldx #0
outer_vscroll_loop:
lda hposn_low,X
sta OUTL
lda hposn_high,X
sta OUTH
inx
lda hposn_low,X
sta INL
lda hposn_high,X
sta INH
ldy #39
inner_vscroll_loop:
lda (INL),Y
sta (OUTL),Y
dey
bpl inner_vscroll_loop
cpx #200
bne outer_vscroll_loop
rts