Mike,
Are you intending to hack this thing?
If you are just looking to remap/reprogram keys on a keyboard hack then you might get some use from ZD Net's free Tradekeys2 utility available at this website:
http://www.pcmag.com/article2/0,4149,19645,00.aspYou will have to copy the address above & paste it in your address bar for it to work.
If you use a hacked keyboard matrix (pcb), you can use this application to make your mame specific controls compatable with any emulator or game.
It actually allows you to save different keymap profiles.
You can have a different profile for MAME, Stella, Impact, etc...
You would simply run the profile before playing the game(s).
Hope this helps...