|
|
Sequential Circuits - Model 800 Sequencer
Overview Dave Smiths first designs were synthesizer accessories, a Model 600 Analog Sequencer (?), the Model 700 Programmer and the Model 800 Digital Sequencer. All these designs
pre-date Dave's use of the Z80 micro-processsor which was launched by Zilog in 1Q 1976. They therefore require a far amount of descrete logic, and the sequence memory is based on the newly available 1k bit SRAM chips. The Model 800 was
launched from Sunnyvale, California in 1977 and was available until 1981. The first few models were built into a tall wooden case and look distinctly hand made.
Description The Model 800 Sequencer is capable of storing 256 notes divided into 16 memory banks.
Each bank holds up to 16 notes. The sequences can be selected or switched instantly in any combination during playback for the ultimate in versatility and ease of use. A dual LED 7-segment display shows the current note number,
while individual lamps display the currently selected memory bank.
Playback speed ranges from 15 times slower to 15 times faster than the recorded speed. The exact half speed or the exact double
speed can be switch selected when desired during playback Sequences can also be stopped and started needed, played back one note at a time, or reset when desired. Switch selectable trigger inputs and outputs are compatible with nearly all
synthesizers.
Individual notes can be reprogrammed without disturbing the
remainder of a sequence, and the timing of a whole sequence can be programmed separately without affecting the pitch. There is a comprehensive footpedal with START RECORD, STOP RECORD and CLOCK ON/OFF functions for remotely
controlling the 800.
Technical Description The core of the Model 800 is the six TTL compatible 2101 memory chips with 256 x 4 bits of storage. |
|
|
|