This is great. I’m not clear on if the bugs you are finding are in Ghidra’s processor model or in the emulator? (Though I think it’s the latter?) Also, why would Ghidra have the best (most accurate?) processor model vs some of the highest quality emulators?

One other question: when the cpu is being emulated at a 50th of its actual speed (or less!) how does replaying recorded input work? Do all games strictly use interrupts to read input or do any poll the state instead (or maybe just at certain sequences or for certain portions of the gameplay)? If the latter, did you have to adjust the key down/key up events you were replaying to avoid a slow-executing cpu missing inputs? (As you might be able to guess, I’m an embedded dev but haven’t dabbled with emulators beyond using them.)

Thanks in advance and again, awesome work!