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About IRQs
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Author:  Muchaserres [ Sat Nov 13, 2004 7:30 am ]
Post subject:  About IRQs

Hi all!

Continuing with my old post "OK, let's talk about accuracy", I'd like to know something. I've been playing around with "Antarctic Adventure (J)" (a classic) sources in order to discover why it is not working on my emu. Using Nintendulator's debugger, I've seen that, after some initialization routines, NMIs get enabled, 0x4015 & 0x4017 regs get updated, and for about 20 scanlines (during VBlank) both CPU and PPU keep running without updating none of CPU registers. My guess is that at this time an IRQ is served. As my emu does not handle any APU part, it runs PRG code during this time, so things get messed.

Am I right?
Thx!

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