I'm pretty sure if RB is working on anything it's the new device based port as Oliver said. If you want to add games to the original M1 you can add them to the M1.XML as long as the board is already emulated. If it isn't emulated, adding new MAME source to the old base of M1 is going to be difficult if impossible. If you want to add old driver code try looking at old MAME sources, stuff from several years ago. I do get the impression, though, from reading your post that you don't have even the slightest inkling about how to do any of this so... That's basically how, if you need help, look for it somewhere else because you're probably not going to get it here.