Hi
I'm trying to emulate LINE interrupts on ZEsarUX. According to the documentation, line interrupt is enabled when bit 1 of register 2AH set. It seems to be correct, as I tried the Chess demo and it seems it uses it
Then I see other three registers:
HSINT
VSINTL
VSINTH
I guess that an interrupt is fired when the scanline is at the position (VSINTL+VSINTH(bit0)) and t-states on line is HSINT. I think my guessing is right.
But, I have some questions:
-When the line interrupt is fired, do I have to call it like a IM2 interrupt? And, do I have to notify somewhere about this interrupt? I read something (translated to russian) like:
byte D [7: 0] in SD on cycle~ IORQ || ~ M1.
- $ FF - personal,
- $ FD - line,
- $ FB - DMA.
??
-Are these interrupts called even if the cpu has interrupts disabled? (DI)
I tried with the chess demo, the image is not seen well (only top half of the screen), and when I fire the interrupt, only the music goes faster, the display is wrong
Thanks
Cesar