Proper way to acknowledge irq
Posted: Wed Dec 06, 2017 1:42 pm
Hi. I'm trying to figure this out.
So I:
1. Set the bit 5 at $4200 for vertical interrupt
2. Set the line to stop at $4209-a
3. Then in the irq handler subroutine, I read $4211,
"and #$80" until it is zero?
This gets me a blank screen.
Thank you for your help in advance.
So I:
1. Set the bit 5 at $4200 for vertical interrupt
2. Set the line to stop at $4209-a
3. Then in the irq handler subroutine, I read $4211,
"and #$80" until it is zero?
This gets me a blank screen.
Thank you for your help in advance.