Look for neogeo.zip in your ROM set. If you want to play Metal Slug or King of Fighters , copy neogeo.zip into the roms folder alongside the game zip files. Other common BIOS files include:
Installing MAME 0.239 ROMs is not difficult, but it is unforgiving. The emulator demands perfection because it emulates hardware at the circuit level. If a single byte of a ROM is off, the game crashes. mame 0239 roms install