Best example I know of is PocketNES, but that was used by Jaleco in a GBA port: https://waxy.org/2004/07/jaleco_borrows/ https://waxy.org/2004/07/jaleco_borrow

Best example I know of is PocketNES, but that was used by Jaleco in a GBA port: https://waxy.org/2004/07/jaleco_borrows/ https://waxy.org/2004/07/jaleco_borrows/ Nintendo has written or contracted a lot of emulators themselves. The grandparent may be thinking of the pervasive use of the iNES header format, which originated with an unofficial (though not open source) emulator: https://wiki.nesdev.com/w/index.php/INES https://wiki.nesdev.com/w/index.php/INES