Mixture generator for electronic organ

Abstract

An electronic organ, particularly of the institutional type employing classical voicing, having Swell and Great manuals as well as a full pedalboard wherein the manuals and pedalboard are multiplexed simultaneously to produce a plurality of synchronized serial data streams. Intermanual coupling is accomplished by connecting the data stream from one manual to the footage generation circuit of another manual, and footages are generated for each manual by utilizing tapped shift registers introducing controlled amounts of delay of the keyboard data before demultiplexing thereof. There is a bank of demultiplexer-keyers for each voice, such as flutes, principals, complex and percussion, which receive the serial data streams from one or more of the footage generators. The demultiplexer-keyers are supplied with tones and function to demultiplex the serial data streams and provide tones to the voicing circuitry selected in accordance with the keydown pulses in the serial data streams. Transposition is accomplished by transposing the demultiplex latch command ahead or behind in time so that the data stream is latched either early or late by one or more time slots depending on the amount of transposition selected. An automatic bass feature permits monophonic bass notes to be played without having to play the pedals, and this is accomplished by coupling into the pedal data stream the lowest data bit originating from the Great manual. Mixtures are generated by selectively delaying the serial data bits both by octave and sub-octave amounts and then combining the delayed data before demultiplexing thereof. The mixture content, which is either unison-mutation-unison or mutation-unison-mutation, is selected depending on the octave of the keyboard in which the key or keys are depressed.