Note selector circuit for electronic musical instrument

Abstract

An electric organ utilizes digital encoding and time division multiplexing to transfer both function selection and note selection information from manually operable switches to respective memories, and to simultaneously produce tone signals corresponding to stored note selection information. A single encoding circuit encodes in binary form the function and note selection information during successive scanning periods established by a single multiplexing circuit. A plurality of stored note codes are transferred on a time division multiplexing basis to a note selector which selectively produces all of the selected tone signals, on one output in multiplexed form. The tone signals are demultiplexed to generate a corresponding plurality of tone signal outputs. An octave selection circuit which is responsive to a part of each note code selectively reduces the frequency of the demultiplexed tone signals. In response to storage of the code for a memory function, the note code memory operates to maintain note codes in storage after deactuation of the switches corresponding thereto until it is updated with new note codes in response to selection of a new set of notes.