The Roland OP-8 interface was designed to control Roland polyphonic synthesizers that were equipped with a DCB (Digital Control Bus) interface via the Roland MC-4 Microcomposer. The OP-8 and synthesizer were connected together using a DCB cable. The OP-8 and MC-4 Microcomposer were then patched together using patch cords via each of their patchbays. The transpose control on the OP-8 was able to transpose the synthesizer up or down by one octave.
The Roland OP-8, released in 1985, was a MIDI-to-CV converter allowing MIDI sequencers to control Roland's modular System 100M. This interface enabled integration of vintage analog synthesizers with modern MIDI equipment. The OP-8 bridged the analog and MIDI eras.
