Unfortunately this was released in 1983, the same year as MIDI.... and it didn't have MIDI. Sales were poor (rumored to be the worst of any Roland product) and that probably accounts for their scarcity even today. I have a vague interest in these... but it keeps fluctuating. As this is basically a keyboard-less SH-101 (with a bunch of added quirks), and I've always preferred the SH-09 to the 101. I suppose I love the idea of this machine but wish Roland had made such a thing a few years earlier. A synthesizer version of the TR-808 if you will.
If you have one and would like the original data from the cassette tape that came with it, there is a blog called Binary Heap that was a WAV file download of it available:
Here is a very basic demonstration of what the MC-202 can
sound like (paired with a TR-606):