If I ever asked this question, I can't find it anymore. When I load nes roms on my everdrive 64, some games will play and others don't. The ones that don't work say "not a valid ines file" or something similar. Does anyone know where I can nes roms that will all work?
They won't all work. The NES emulator is not very good for the N64 and was not created by KRIKzz so he does not offer support for it. Maybe some people here can help you find better ROMs, but don't expect it to be that great.
I don't think it's a problem of file, more a problem of mapper, simple games should work (Mario 1/2/3, Castlevania 1/2 etc...) complex games wont (Castlevania 3, several japanese games with extra audio...).
