I found a good tutorial/demo on doing a split screen effect with the MMC3 irq, originally written in nbasic. I used nbasic to translate this to nesasm, and then I hand-translated it to asm6.
The demo does not work in Nestopia or Nintendulator, but does work in JNES and FCEUXD. The IRQ routine should be setting the background color to green, but it appears as though it is never happening. It is almost as though "cli" is being ignored...which must mean something else is wrong.
http://www.geocities.com/zomcoder/splitscreen_mmc3.asm
Any help would be appreciated.
The demo does not work in Nestopia or Nintendulator, but does work in JNES and FCEUXD. The IRQ routine should be setting the background color to green, but it appears as though it is never happening. It is almost as though "cli" is being ignored...which must mean something else is wrong.
http://www.geocities.com/zomcoder/splitscreen_mmc3.asm
Any help would be appreciated.