It would be trivial to add an option to MAME's UI for "add custom ROM for X" where it was made clear that the files expected were the same as a certain ROM but the checksums weren't being checked. The user would be "protected" because unless they explicitly added this custom ROM ...

Erm, what intentional reasons, out of interest? Either you have a UI that allows you to conveniently run the ROMs you want (which are supported by MAME, ie. if I throw it at MAME it will work, whether the UI thinks it has an invalid checksum or not) or you might as well tell people to set up .cmd fi...

Shouldn't MAME's UI provide some mechanism to add these "unrecognized" hacks, then? Perhaps this one is a hack that was done more recently, but I'd like to play it from the MAME UI and I can't because it obviously says that the game has invalid checksums.

So I've found a bootleg ROM for the arcade SF2: The World Warrior that replaces sf2jh.zip. It's a boss hack of the original Japanese version and seems to be somewhat widespread with a bunch of YouTube videos showing gameplay from it. When I replace sf2jh.zip with it and run it from the commandline (...

Hello,

It seems MAME currently doesn't support emulation of Tetris: The Grand Master 3 - Terror-Instinct, by Arika. Is there any work on this / plans to support it?