This is a great idea, and hopefully we'll see a VST interface for something like this too someday. I think the Sega genesis is a noisy FM synth but it's got a really gritty charm to it that definitely brings back memories for me.
"WHAT IS IT?
GenMDM is a music interface for your SEGA Genesis or Mega Drive console.
Use GenMDM to write sweet chiptunes using your favourite MIDI / audio sequencing software. GenMDM will appear as a MIDI output device on your Windows, Mac or Linux-based computer. GenMDM will respond to MIDI notes and MIDI CC data, and will give you a high degree of real time control over the sound chips inside of the SEGA console.
All voices and sound functions of the standard SEGA FM and PSG sound chips can be controlled via MIDI. There is a small FAQ in this thread on chipmusic.org. You might be interested in reading it."
http://little-scale.com/
