l_oliveira
Grand Master
CPS1 has a lot of tricky, protection related problems to tackle:
Mapping of graphics roms are controlled by a PAL/GAL which vary per game.
If you look my videos of the Daimakaimura game you will notice the sprites are screwed up on my game, that's because the sprites data are being put on a wrong position of the GFX roms memory space.
Mapping of graphic registers on CPS1 games are different per game (as per different CPS-B chip types and also extra protections like reading the chip ID register and multiply check. Also there's a PAL which set the CPS-B chip register base address for the CPS-B chip. Finally, a few select games use odd memory maps (again set by a differently programmed PAL chip).
I have the impression that this French B board MCU patches the roms as they are loaded into the board. A CPS1 multigame would be a lot trickier to make than a CPS2 one, due to the fact that CPS2 games don't need much patching, just decryption to work in it.
Mapping of graphics roms are controlled by a PAL/GAL which vary per game.
If you look my videos of the Daimakaimura game you will notice the sprites are screwed up on my game, that's because the sprites data are being put on a wrong position of the GFX roms memory space.
Mapping of graphic registers on CPS1 games are different per game (as per different CPS-B chip types and also extra protections like reading the chip ID register and multiply check. Also there's a PAL which set the CPS-B chip register base address for the CPS-B chip. Finally, a few select games use odd memory maps (again set by a differently programmed PAL chip).
I have the impression that this French B board MCU patches the roms as they are loaded into the board. A CPS1 multigame would be a lot trickier to make than a CPS2 one, due to the fact that CPS2 games don't need much patching, just decryption to work in it.