Home
Analog Articles
Manuals
Synth DIY
Site Overview
 

Index
ARP 2500
ARP Filters
ARP Quadra
SCI 700
SCI 800
Oberheim OB1
Roland Seq'rs
Roland 700

 Email me

Created by
 Western Graphics
Last modified
 08 February, 2006
 

Early Roland Sequencers (1977 - 1984)

Overview After a couple of traditional 8 and 12 step analog sequencers, Roland became a pioneer of digital sequencing in the late 1970's. They quickly achieved market leadership with CV/gate interfacing and then successful transferred their ideas into the new MIDI standard from the mid 1980's.

This leadership was made possible thanks to the invention of the micro-processor for controlling the sequence, and large amounts of RAM memory for storing the note data. By the early 1980's memory prices had fallen sufficently for whole songs to be stored, and with the arrival of MIDI the flood gates opened and the Roland hardware seqeuncer became hugely popular.

717A Roland got started with analog sequencing when they designed the mighty System 700 Modular Synthesizer in 1977.
One of the most complex analog sequencers ever created the large 717A module has:

• 12 steps, with step selector switch
• 12 red step LED's
• 3 channels (A, B, C) plus fourth channel for clock control
• Internal clock with Rate and PW
• Clock rate can be controlled by fourth channel
• 4 Modes (manual, A, A+B, A+B+C)
• Start, Stop, Continue, Manual Step controls
• Serial and Parallel Outputs

The 717A does miss out on a Random mode and the channels don't have quantizers. The design is based around some unusual logic chips (TV channel selector chips) and a discrete temperature compensated master clock.

182M The entry 100M analog modular synthesizer of 1978 contains a much simpler 8-step analog sequencer.

• 8 steps with step selector and 8 red step LED's
• 2 channels (1,2), unquantized
• Internal clock with Tempo and Gate Time
• 3 Modes (single, step, repeat)
• Start/Stop controls

The design is based around a MC14022 divide-by-8 chip and a discrete voltage controlled clock. The design is very simple to replicate, and we have a project to build one. more »


104 Whilst the analog synthesizer section of the Roland 100 System may be looked down on, the 104 sequencer module is actually a 717A sequencer module slimmed down to fit the 100 System format.

• 12 steps, with step selector switch and 12 red step LED's
• 2 channels (A, B)
• Internal clock with Rate and PW
• 3 Modes (manual, A, A+B)
• Start, Stop, Continue, Manual Step controls
• Serial and Parallel Outputs

The design is the same as in the 717A, using the same strange TV channel selector chips.

MC-8 Roland's first digital sequencer was introduced in 1977 and was based on a TTL prototype developed by Ralph Dyck in Canada during the early 70's. Roland liked the prototype, but switched to the new Intel 8080 8-bit microprocessor and added 4kbytes of RAM to hold 8 "tracks" and 1,100 notes. They names the new device a "micro composer" and used the "MC" model type for the next 25 years.

Notes could be recorded in real-time or entered via the calculator keyboard. At over $4500 the MC-8 sold to the music elite, and created a revolution by enabling whole songs to be sequenced. The memory could be expanded to a total of 16Kbytes with the $650 MO-8 memory expansion board.

CSQ-100  In 1979 Roland pushed on with sequencing design and developed a single channel micro-processor based sequencer, that sold for under £1000. The micro-processor revolution of the late 70's meant that cheap 8-bit processors such as the 8048 could be used to digitally record analog CV and gates signals.

With SRAM chip prices coming down, Roland could afford to put a 512 byte chip into the CSQ-100 and store up to 168 notes in 2 "tracks". Unfortunately the memory was volatile, with no battery back up. However this CSQ-100 was a big step up from previous digital sequencers such as the EMS 256 note sequencer or the Oberheim DS-2A.

CSQ-600 A year later and Roland refined the digital sequencer by adding battery backed memory, and increased the memory size by 8 times, enabling 4 "tracks" of 150 notes each. Whilst there were no note editing facilities, the seqeuncer did enable simple lines to be stored and play back accurately thanks to the internal note quantizer.




MC-4 Although the MC-8 was a commercial failure (it was simply too expensive to make), Roland were quick to learn the lessons and exploit the latest technology. With the MC-4 they reduced the tracks to 4, but greatly improved the user interface, making song creation and editing a less painless task.

The internal memory of MC-4B is 48Kbytes. The MC-4A (16Kbytes) is expandable to 48Kbytes with the optional OM-4 (32K byte RAM  Board). The 16Kbyte memory can memorize up to 3,750 notes depending on step time, and the Measure End number. This is expanded up to 11,500 notes at 48K bytes.

MSQ700

MSQ100

JSQ60