Andy, what I mean is that I need, as I said, A LOT of keys, 16 at least. is to build a dedicated game machine (using mame emulator), where two players will play at once and a lot of keys are pressed at the same time, in a future it could be expanded to 4 players and the problem is even greater.
I've searched the site before posting but didn't found what I needed.
AFAIK the keyboard uses a 16x8 matrix, if I could use one of each columns I would be almost there, but one problem is that I can't use any key in the keyboard, and the other problem is that I'm not sure how to be able to decode the matrix for my keyboard in an easy way, since as far as I saw all the keyboards seem to be different to each other.