Check all edge interrupts

This commit is contained in:
Byron Lathi
2023-11-18 15:00:44 -08:00
parent dea6227958
commit 1b78f51933
3 changed files with 65 additions and 13 deletions

View File

@@ -1,23 +1,70 @@
.MACPACK generic
.export _init, _nmi_int, _irq_int
.import tmp1
CMD = $effc
DAT = $effd
.zeropage
finish: .res 1
curr_irq: .res 1
.code
_nmi_int:
_irq_int:
; We should have triggered interrupt 1
stz CMD
lda DAT
cmp curr_irq
bne @bad
lda #$ff
sta CMD
lda #$1
sta DAT
inc curr_irq
beq @good
cli
rti
@good:
lda #$6d
sta $00
sta finish
@bad:
lda #$bd
sta finish
_init:
lda #$20
sta CMD
lda #$ff
sta DAT
lda #$40
sta CMD
lda #$ff
sta DAT
ldx #$ff
txs
ldx #$20 ; enable
ldy #$ff
jsr cmd_all
ldx #$40 ; edge type
ldy #$00
jsr cmd_all
stz curr_irq
cli
@end: bra @end
jmp wait
cmd_all:
txa
add #$20
sta tmp1
loop:
txa
sta CMD
tya
sta DAT
inx
cpx tmp1
blt loop
rts
wait:
bra wait