I have dumped and tested the following:
BGSB3B PAL – I found this on my Dungeons and Dragons: Tower of Doom board
C2VA3 PAL – This is in the black all-in-one boards. Not sure if its the same for all games, this is from Marvel VS Capcom
I had an issue with the BGSB3B one, it didn’t work initially and just gave a black screen. Doing some logic analysing of the original PAL showed that pin 12 was permenantly LOW and on mine it was set HIGH.
I don’t know or understand a great deal about programming PLDs but I think that pin 12 is set high by the line “!B0 = ‘b’0;”
I think this means set to binary OFF and maybe if its active low then these things are swapped. This is all a huge assumption and am probably way off but by changing the above line to “!B0 = ‘b’1;” all became good and well so I’m claiming it as a victory.