Output unit and keysoft for the Polyformant - the final stage of the polyformant together with the software and useful hints

7-92 — elektor july/august 1982 output unit and keysoft for polyformant The actual sound generators of the poly- phonic synthesiser are still going to be analogue. All ten synthesiser channels consist of voltage controlled circuits (VCO, VCF, VCA). Therefore they require analogue control voltages to determine the pitch, and gate pulses which effectively start and stop the envelope generators. However, the microprocessor in the digital keyboard (on the CPU card), only supplies binary coded data (bits). Furthermore it does not address all ten channels simul- taneously; instead, it deals with them in turn. First channel 1, then 2 and so on. One cycle is completed when channel 10 is updated, after which new data is applied to channel 1. Therefore the out- output unit and keysoft for polyformant the final stage of the polyformant together with the software and useful hints After the CPU described in the May issue and the "Polybus" published in last month"s magazine it"s time to add t...