Digital Control Bus

Digital Control Bus or DCB is a proprietary data interchange interface by Roland Corporation, introduced in Roland Juno-60 in 1984. DCB functions are basically the same as MIDI, but, unlike MIDI, which is capable of transmitting a wide array of information to and from a particular instrument, DCB could provide note on/off and program change only. Data were relayed using a thick cable that connected to a port vaguely resembling a parallel port on a computer.

Physical appearance

DCB was made in 2 variants, using 15-pin and 20-pin sockets and cables.

Supporting equipment

DCB era wasn't long and it was throughly replaced with MIDI in the beginning of 1980s. Roland produced these synthesizers with DCB interfaces:

• Roland Juno-60
• Roland Jupiter-8 (later models)
• Roland Juno-6 (can be optionally fitted with DCB)

Roland produced at least two DCB sequencers:

• Roland JSQ-60
• Roland MSQ-800

The latter was capable of saving eight sequences or a total of 3000 notes and was also capable of transmitting and receiving data via MIDI. However, this did not consitute a direct bridge between DCB and MIDI. Roland later released the MD-8, a rather large black box capable of converting MIDI signals to DCB and vice versa. While this allows note on/off to be sent to a Juno-60 by MIDI, the fix pales in comparison to the full MIDI implementation on the Juno-60's successor, the Roland Juno-106.

Nowadays, few companies offer similar conversion boxes to attach DCB to regular MIDI buses to support these vintage synths in modern sound production environments.