> Thanks for replying.
> That was what i had in mind...
> I'm a programmer and know assembly, c & C++.
> Can you point me to some tools?
> Are there any specific tools for this? (MAME and GAMES)
> I have never done anything in this area...
> Thank you
well if you just want to be able to see the code running then you can run MAME with -debug
the code you see disassembled and running there is the game code.
there's a decent set of help available if you type 'help' there
beyond that, if you actually want to edit / write code it's very much going to be determined by the system you want to look at, there are tools out there for most of the major processors.
it's not really the kind of subject where there's a single 'good' answer to give you, it's a lot of work and research that will need doing however you look at it.