I've been curious how difficult it would be to edit the graphics in a cps1 arcade game. I found this document for the CPS2 and graphic editing for that:
I've found in the past the cps1 and cps2 work similarly for a lot of things so I speculated maybe the graphics in the cps1 work similarly to the cps2. According to the info in the above link it sounds like the graphics are split between multiple roms. I opened up the graphics roms of street fighter 2 champion edition in tile layer pro (sega master system format is the one that seems to work right). I opened the first four and they all seem to contain some of the data for the same tiles. To put it into perspective I plopped the sprite test menu assembled images in between the split rom image data:
It seems if someone wanted to edit the graphics for the cps1 you would need to edit data in four separate roms since the tile data is split between four different roms. I suppose the best approach would be to program a utility that takes an edited graphic and automatically splits and inserts the data for you.
I wonder if it would be difficult to reprogram the game so it reads the data from one rom instead of having it split across four separate roms. I'm curious why it was done this way, perhaps it worked better with the hardware or it was some sort of precaution to stop people from changing the game's graphics?