A MIDI-like standard would be much smaller, but also a lot tougher to implement. Actually, MIDI travels at 34.2 kbps (or something like that) serial. On my amiga, I connected a midi tranciver to the serial port, and the modem plugged in on the other end. If Mel can get the port going at 34.2kbps, then connecting midi devices ought to be fairly easy.