Posted By
bubis
on 2018-04-24
09:32:11
|  Re: IRQ Interrupt examples
This is what you do if you don't need ROM.
rasterline = 200
sei
sta $ff3f
lda #lo(irq)
sta $fffe
lda #hi(irq)
sta $ffff
lda #2+hi(rasterline)
sta $ff0a
lda #lo(rasterline)
sta $ff0b
dec $ff09
cli
...
irq:
pha
txa
pha
tya
pha
...
dec $ff09
pla
tay
pla
tax
pla
rti
|
