Why? Because modern MAME has "drifted." A ROM that perfectly emulated Donkey Kong at 0.130 was marked as "bad dump" at 0.140, only to be marked "good" again at 0.200 after new decapping technology revealed the true microprocessor layout. The 0.130 set represents a consensus reality of arcade hardware from 2009—a frozen moment in digital archaeology.
But for the golden age (1978-1998), is arguably 99.5% complete. For 90% of retro gamers, the missing 0.5% is irrelevant. mame 0.130 romset