This unit functions and is in good shape but does show some wear and tear.
The M3R is a 19" rack mount digital synthesizer module featuring the AI2 synthesis found in the M1 series of synthesizers from Korg. It cost about half as much as an M1 and offered a lighter wave rom as a result but still has a full set of excellent sounds for the player.
In Combination mode it offers up to 8 programs simultaneously It also includs a full set of effects and was 16 part multitimbral playback via MIDI.
It is programmable in a scaled down form by way of a single oscillator which could have two wave forms