: MAME is strict about BIOS versions. An older neogeo.zip may fail to work with newer versions of MAME because the emulator expects updated dumps of the system files.
Instead, they relied on a central chip containing the system software—the BIOS. When emulating these games, MAME requires a digital dump of that system chip packaged as neogeo.zip to handle basic inputs, audio routing, and regional configurations. Technical Specifications: The Anatomy of neogeo.zip neogeo bios for mame