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About 10 years ago I tried to write a gameboy emulator based on a pdf document i found on the internet somewhere. I ended up finding the documentation wrong in
by Gunax 3y ago
About 10 years ago I tried to write a gameboy emulator based on a pdf document i found on the internet somewhere.
I ended up finding the documentation wrong in a handful of places, which made the project tedious. Did you find that document reliable?
- throwaway202351 3y agoNot OP, but if you mean that ~200 page doc, it's pretty good but has some issues and inaccuracies some places, but it might just be me. Some things like how carries are supposed to work in some edge cases, for example, but I think it was written under the assumption that the reader would be familiar with a standard Z80 chip. Something else I noticed was that there were some specs that I guess the gameboy follows, but not exactly. For example with swapping pages, it's supposed to take up to (I forget the actual numbers) 50 cycles, but the actual gameboy always finishes in exactly 38 cycles, and some games are written for that. In the end, what worked for me was finding a working emulator that would output the registers' states every operation, and then making sure mine would match up with it.