11 March 2016 - Forum Rules

Main Menu

MAME Checksum error

Started by Bugnug, January 16, 2023, 10:40:38 PM

Previous topic - Next topic


After years of wanting to play Super puzzle fighter 2 but being unable to due to being colourblind, yesterday I stumbled across thecoloursguy patch to turn the yellow gems white.

After patching I tried to play it on Mame and would get a checksum error with the patched file 'pzf.04'.
After hours of trying different methods of patching/mame versions/different patches with no luck i came across some info that you can run mame roms with checksum errors from the command prompt (see below) and it will still have an error but you will then be able to continue on into the game if you choose to do so. I did this and the game worked perfectly with white gems.

E:\MAME PC>mame.exe spf2t
    EXPECTED: CRC(b80649e2) SHA1(5bfccd656aea7ff82e9a20bb5856f4ab99b5a007)
       FOUND: CRC(01bf5ff5) SHA1(e24b145fbfb753467bdbbf106b75875399cae88e)
WARNING: the machine might not run correctly.

So I know the patching and rom is working.

Is there any way that I can bypass this check in the Mame UI? It seems weird that it can from the cmd prompt but not the UI.

I don't want to play on my PC i want to use the ROM on a rpi2jamma setup in an arcade machine so the cmd prompt option is useless to me unfortunately.

Is there something I'm missing as I'm a noob?
Thecolorsguy makes note in his Rom/Iso info
pzf.04 before the patch: b80649e2
pzf.04 after the patch: 01bf5ff5

Which is what is contained in the error report above. Am i supposed to do something with this info?

Any help will be much appreciated :)


That is a rare type of colourblindness.

Anyway MAME for whatever reason can be sticklers about having modded games run, and it seems to be a very deliberate and concious design decision*. Indeed I am somewhat impressed there is even a provision for it as in the past people had to compile the emulator anew having lost the checks and if the UI does not provide an option, or you can't force it through by some other means (make a batch file to load that specific game or something), you may end up seeking out/creating such a version. If you have to make one I have not checked the code in a while and it was never obfuscated or anything so it is more a matter of losing some checks, or making it not care about the results rather than having to actually code anything.

*to the point where various different people asking on the MAME forums about it over the course of years get told in no uncertain terms that it is not going to happen. I can only guess that with MAME catering to such a small batch of games on a per board basis (how many have more than 10?) that between game specific code in the past and various fun with ROM hackers and such colouring way outside the lines that they adopted the "our suitably blessed version or you are on your own approach" to spare themselves the headache.


I can understand with MAME that, since games are constantly getting redumped and/or redefined what a "good" dump is, they wouldn't want people making bug reports for ROM sets other than the ones designed to be supported.
And that with unsupported ROM hacks, it would create a lot of work to tell if it is an actual emulation bug or just bad ROM hacking.

Though the MAME64UI or whatever it is called that I use, normally does allow me to just click OK and continue trying to run the game anyways if it finds a mismatch.
"My watch says 30 chickens" Google, 2018


I remember back in the day there were dozens of different versions of MAME (or a dozen, at least) catering to a variety of different audiences. Surely by now there's a fork that is more permissible?
This signature is an illusion and is a trap devisut by Satan. Go ahead dauntlessly! Make rapid progres!