David Haywood's Homepage
MAME work and other stuff
February 8, 2016 Haze Categories: General News. 5 Comments on A game of Cat and Mouse

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.

f205v updated his site with the details .

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.

Cat and Mouse Cat and Mouse Cat and Mouse
Cat and Mouse Cat and Mouse Cat and Mouse


You can follow any responses to this entry through the RSS 2.0 feed.

hello program ROM 2B is a 2732 and I gave the dump to f205v with the rest of the dump. I hope this is useful

vernimark > we already had a good dump of program rom 2B for set 1 (f205v / you dumped it a few years ago) It’s very much appreciated.

your set is ‘catnmous’ in MAME (aka ‘set 1’)

‘catnmousa’ (aka ‘set 2’) is from a different PCB with different code revision, and needs a different rom for 2B, so whoever owns that PCB needs to dump it (if the PCB still exists) unfortunately we don’t know who dumped that set or if they still have the PCB.

I don’t know the difference between the 2 sets, maybe one version is a bug fix, or a more difficult / easier version, but without the missing ROM data for that version the 2nd set can’t run.

thank you for the explanation. In case I’ll found another board I’ll check.

I actually used the photo to determine how the sprite ROM banking works: you can see that the extra address wire run on the component side of the PCB is soldered to an output pin on one of the sound latch chips. This is a great example of how important decent quality photos can be. A list of “major” chips is not sufficient.

BTW vernimark would you be able to identify the crystal and TTL chips on the sound PCB? The photo has too much glare and fringing to read them.

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.