: A full "working" set typically includes approximately 7,396 games .
If you want to be squeaky clean, buy the Arcade Archives or Hamster releases on Switch/PS4 and use MAME 0.139 only for games not commercially available. mame 0.139 romset
You need a (sometimes called "0.139 ROMs"). It is a matched set – ROMs from any other MAME version (0.138, 0.140, 0.155, etc.) will have mismatched checksums and will not work or will show missing files. : A full "working" set typically includes approximately