DCB (short for Digital Communication Bus) was Roland's short-lived precursor to MIDI, and indeed many of its ideas were merged with Sequential Circuits's in order to create the MIDI specification.
While DCB isn't as featureful as MIDI, a MIDI to DCB converter at least allows you to control a DCB-based synthesiser via MIDI without modifying it.
- Kenton Pro-DCB
- Roland JSQ-60
- Roland Juno-60
- Roland Jupiter-8
- Roland MC-4 with OP-8 CV Interface
- Roland MD-8
- Roland MSQ-700