Because ROM sets are large (often over 40GB for a full set including CHDs), they are typically hosted on archive-based sites rather than standard download portals.
: MAME is unique because ROMs are not "universal." A ROM set designed for 0.139 will only work reliably with an emulator built on that specific version. Using newer or older ROMs often results in "Missing Files" errors. The "UPD" (Update) Feature mame 0139 romset download upd
: The Internet Archive hosts the complete "Ghostware" collection for MAME 0.139, which includes ROMs, CHDs (hard drive images), and Samples (sound files) [17, 19, 25]. Because ROM sets are large (often over 40GB