MAME handles files using a strict tracking database. As the MAME team finds better, cleaner dumps of original arcade microchips, they change the required file names and contents inside the zip files.

: While a game ROM contains the actual game data (graphics, levels, music), it cannot boot without the underlying motherboard firmware.

: In MAME emulation, the ROM set and BIOS versions must match the emulator's version. For MAME4droid (0.139u1)

It is the standard set used by Mame4Droid on Android , which is notorious for needing specialized BIOS files like neogeo.zip for games to function properly. Why You Need the Specific 0.139u1 BIOS Pack