Mainstream MAME evolves constantly. However, around 2015-2016, the development team made a controversial shift: they replaced the old, efficient MAME4ALL core with a more accurate, but slower, iteration. For single-board computers like the Raspberry Pi 3, this was a disaster.
Because of its hybrid nature,
If you can't find a pre-made set, you can build one using and the official MAME 2003-Plus DAT file . Recommended ClrMamePro Settings: Mode : Set to "Non-Merged". mame 2003-plus reference: full non-merged romsets
Once you have your "MAME 2003-Plus Reference Full Non-Merged" folder (let's call it mame2003-plus-roms ), here is how to operationalize it. Mainstream MAME evolves constantly