In a few months, MAME 0.140 would come out. Then 0.150. Then 0.200. Things would break. ROMs would be renamed. New protection chips would be discovered and emulated. The "Complete" set he had today would become outdated, a relic of a specific snapshot in preservation history.
The MAME 0.139 ROMset includes:
MAME (Multiple Arcade Machine Emulator) follows a strict versioning system. Every time a new version is released (roughly once a month), the internal code changes. This changes how the emulator reads the original arcade game ROM chips. mame 0139 romset