Does anyone know if there's a fix to make Tapper work in Mame .212? I've searched the web + posted at Mamedev forums but can't find any information about this. There are a number of games apparently based on the same code that also don't work.
I doubt you're referring to
this open bug report about frameskip+throttling, so it sounds like you are either missing a driver file (midssio.zip?)
or using a ROMset that doesn't match your version of MAME.
Penalty points if you're using a "no-nag" build
before confirming that all of the desired games/drivers work properly.

Those info screens are
very useful for troubleshooting.

Scott