Moog 1982 Product Catalog Featuring the DSC - Digital Sequential Controller

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Note the DSC in the 2nd image. Kind of looks like a Source minus keys. You can see one in the flesh in this previous post. According to the catalog:

DSC-To meet the need of performers demanding the versatility and freedom that can be attained with a sequencing device, Moog introduces the Digital Sequential Controller (DSC).

The DSC is an intelligent controller - it stores information played on a synthesizer keyboard and reproduces and manipulates that information in musically useful ways.

The DSC has three recording modes - normal, metronomic, and expanding. In the normal mode all keyboard technique (key depressions, slurs, etc.) - is recorded exactly as played. The metronomic mode disregards timing information and assigns the same time value to each event. The expanded mode stores anything that can be played on the synthesizer (including pitch bend, vibrato, and glide).

Four sequences can be stored (total storage approx 800 notes). The DSC will send the sequence information back to "play" the synthesizer. Sequences can be "chained" for playback in any particular order. Playback can be stopped and continued, or run in "single-step" mode. Notes within a sequence can be edited and corrected.

A "transpose chain" can be programmed and stored to produce automatic key changes. Output pulses can be programmed on any note or notes to trigger an external synthesizer, start or stop a tape recorder, etc. Glide can be added to any recorded sequence, in addition, recorded glide can be converted to quantized glissando.

The DSC generates a SMPTE compatible sync signal for synchronization with tape or additional controllers. All DSC information can be saved on a standard cassette for later re-use.

The DSC is more than a "sequencer", it is the most versatile controlling device available.