More thinking out loud and trying anything... am I setting up my vertical blank interrupt correctly?
Code:
;-----
; install interrupt
move.l VBRPtr,a0
move.l #VerticalBlankInterrupt,INTVECTORL3(a0)
move.w #$c020,INTENA(a6)
Code:
VerticalBlankInterrupt:
movem.l d0/a6,-(sp)
lea CUSTOM,a6
btst #5,$1f(a6) ;check if it's our vertb int.
beq.s .notvb
*--- do stuff here ---*
bsr UpdateFrame
*--- do stuff here ---*
moveq #$20,d0 ;poll irq bit
move.w d0,INTREQ(a6)
move.w d0,INTREQ(a6)
.notvb:
movem.l (sp)+,d0/a6
rte