mirror of
https://github.com/irmen/prog8.git
synced 2024-12-03 13:49:23 +00:00
44 lines
695 B
NASM
44 lines
695 B
NASM
|
; backup/restore the zero page
|
||
|
|
; this is in a separate file so it can be omitted completely if it's not needed.
|
||
|
|
|
||
|
|
_il65_save_zeropage
|
||
|
|
lda #%00101111
|
||
|
|
sta _il65_zp_backup ; default value for $00
|
||
|
|
lda #%00100111
|
||
|
|
sta _il65_zp_backup+1 ; default value for $01
|
||
|
|
ldx #2
|
||
|
|
- lda $00,x
|
||
|
|
sta _il65_zp_backup,x
|
||
|
|
inx
|
||
|
|
bne -
|
||
|
|
rts
|
||
|
|
|
||
|
|
_il65_restore_zeropage
|
||
|
|
php
|
||
|
|
pha
|
||
|
|
txa
|
||
|
|
pha
|
||
|
|
sei
|
||
|
|
|
||
|
|
lda $a0 ; save the current jiffy clock
|
||
|
|
sta _il65_zp_backup+$a0
|
||
|
|
lda $a1
|
||
|
|
sta _il65_zp_backup+$a1
|
||
|
|
lda $a2
|
||
|
|
sta _il65_zp_backup+$a2
|
||
|
|
|
||
|
|
ldx #0
|
||
|
|
- lda _il65_zp_backup,x
|
||
|
|
sta $00,x
|
||
|
|
inx
|
||
|
|
bne -
|
||
|
|
cli
|
||
|
|
pla
|
||
|
|
tax
|
||
|
|
pla
|
||
|
|
plp
|
||
|
|
rts
|
||
|
|
|
||
|
|
_il65_zp_backup
|
||
|
|
.fill 256
|