Vas Crabb made some improvements to Cat and Mouse a while back, but in the end we discovered that one of the graphic roms had been dumped as half size.
We knew Vernimark owned a PCB of this game, so I got in contact with f205v to ask him if he could double check the ROM and dump it as the correct type. This process took a couple of weeks, but eventually f205v got back to me to tell me that the job had been done.
Using these details, and a bit of deduction Vas was able to find how the game banks the sprite ROM; on the PCB there’s a wire leading around the PCB from one of the pins on the chip at L14 (the graphic rom) which I guess has something to do with it, see the image linked below. In emulation terms, it’s an otherwise unused bit of the sound latch. Also note, the position next to the socket is marked for a 2716, which is presumably why the rom ended up being dumped half size, the ROM on the PCB is actually a 2732.
Vas also improved the colours in the game using the close-up of the resistor network
however it is possible one of the values is still slightly wrong because the 3rd resistor down on the left-most column looks like it might hav been repaired / replaced in the past, as Vas noted in the driver
“Blue uses 47R and 820R on the PCB we have a photo of, although the 47R resistor looks like it could be a bad repair (opposite orientation and burn marks on PCB)”
So if anybody else has a Cat and Mouse to double check that it would be good, the impact of it potentially being wrong is nothing serious, as the value we’re using works well, but it would be good to know the original value for sure. Also if anybody has a Cat and Mouse PCB that runs the ‘set 2’ from MAME then the last program rom on that set still needs redumping, it should also be a 2732, not a 2716, Vernimark was unable to help with that because his PCB is the ‘set 1’ PCB in MAME.
Anyway, here are some screenshots of it running with the improved colours and correct sprites; the old lady with broom sprite was completely missing in the previous graphic roms, as was one of the orientations for the dog.