cc65/libsrc/cbm510/waitvsync.s

29 lines
504 B
ArmAsm

;
; Written by Groepaz <groepaz@gmx.net>
;
; void waitvsync (void);
;
.export _waitvsync
.import PALFLAG
.import sys_bank, restore_bank
.importzp vic
.include "cbm510.inc"
_waitvsync:
jsr sys_bank ; Switch to the system bank
sei
ldy #VIC_CTRL1
@l1:
lda (vic),y
bpl @l1
@l2:
lda (vic),y
bmi @l2
cli
jmp restore_bank