A full "Machine ROM" set for this era typically occupies around 70GB , though this excludes larger CHD (Compressed Hard Disk) files required for more modern 90s titles. Popular Games in the 0.139u1 List
Donkey Kong , Galaga , Centipede , and Frogger . mame 0.139u1 roms list
Mortal Kombat (1-3) , NBA Jam , and Smash TV . A full "Machine ROM" set for this era