Demystifying MAME ROM Sets

Compared to other emulators, MAME is software that is still being developed due to newer arcade systems and games that appear on the market. Contrasted to, say Sega Megadrive or Super Nintendo Entertainment System, older systems are not being developed such that emulators only progressively get better and have to just support a finite set of ROMs.

This leads to some confusion when running a MAME emulator, or even, which MAME emulator version to run a ROM with. One would observe that a lot of players are still using a MAME emulator dated back in 2003, which is counter-intuitive to a software user expecting a newer and better version for the current year.

Picking a MAME emulator version depends on various parameters such as:

the available set of games; upon the release of certain MAME emulator versions, different ROM sets are created based on particular databases. The databases are then used by collectors to find ROMs and assemble a ROM set,
the available hardware; since MAME emulation is an on-going development, a very recent MAME emulator might greatly exceed the constraints of the available hardware

There are some essential milestones in the development of MAME for which certain ROM sets are designed for.

MAME Version	ROM Set
MAME 2000	`0.37b5`
MAME 2003	`0.78`
MAME 2003-Plus	`0.78` with `0.193` rollback set
MAME 2003 Midway	`0.78`
MAME 2009	`0.135u4`
MAME 2010	`0.139`
MAME 2015	`0.160`
MAME 2016	`0.174`

As far as the hardware requirements go, a Raspberry Pi 4 released in June 2020 will run a MAME ROM set from 2016, that is a 0.174 ROM set, extremely poorly with massive slowdowns and lag and will not run a MAME release game from 2020 at all.

Unfortunately, the retro-emulation scene prefers to use small commercial SBCs in order to emulate games but, in what regards MAME at least, Raspberry Pis can only really emulate up to, perhaps, MAME ROM sets released up to 2010. Fortunately, retro-emulation pertains to running games that are older such that releases up to 2010 might seem fine.

On the other hand, collecting all ROM set versions may be beneficial for users that want to use netplay, in particular, over the Internet, anonymously, because the same ROM is required for all players willing to join the game.