I heard that old chips without the "C" are dumpable, ie. 1655 but not 16C55.
Maniac (note:it's a PIC1655A) was dumped by kevtris a couple of years ago. I can make it playable in MESS, but not without a few hacks in the MCU core. Apparently the customer could provide I/O config, this isn't implemented in MESS yet.
Oh, and I forgot to mention new additions, Entex Baseball(1) works great in MESS, as does Tomy Pac Man.