In MAME, games are organized into "Parents" (the main version) and "Clones" (alternate versions).
At the time of its release, MAME 0.78 represented a major milestone. It added support for the (Capcom Play System 2) encryption, improved Neo-Geo emulation, and fixed countless driver bugs from earlier versions. mame 0.78 rom set
In modern MAME, ROM management has become a science of parent sets, clone sets, and device ROMs. MAME 0.78 was among the last versions where the was the norm. This meant each game’s ZIP file contained everything needed to run that game on its own. You didn't need a separate "parent" ROM or a "Neo-Geo BIOS" file. This simplicity is a massive draw for beginners. In MAME, games are organized into "Parents" (the