mirror of
https://github.com/cc65/cc65.git
synced 2024-12-28 06:30:16 +00:00
25 lines
496 B
ArmAsm
25 lines
496 B
ArmAsm
;
|
|
; 2021-04-01, Greg King
|
|
;
|
|
; void waitvsync (void);
|
|
; /* Wait for the start of the next video field. */
|
|
;
|
|
; VERA's vertical sync causes IRQs which increment the jiffy timer.
|
|
;
|
|
; Updated by ZeroByteOrg to use Kernal API RDTIM to retreive the TIMER variable
|
|
;
|
|
|
|
.export _waitvsync
|
|
.importzp tmp1
|
|
.import RDTIM
|
|
|
|
.proc _waitvsync: near
|
|
jsr RDTIM
|
|
sta tmp1
|
|
keep_waiting:
|
|
jsr RDTIM
|
|
cmp tmp1
|
|
beq keep_waiting
|
|
rts
|
|
.endproc
|