I've got a few 7800 NTSC games which won't play nice with my PAL 7800, so I've decided to change the NTSC-roms to PAL-versions of the same game. I've found the guide for the 32k ones and those worked fine, but now I've got a 48k pcb (One on One) where there are 2 mask roms on the PCB, a 32k and a 16k mask rom. How can I convert the pcb for either one 64k 27c512 eprom or two eproms (32k 27c256 + 16k 27c128)? This is the board in question C026445.