Kimball International, Inc.

Melvin J Schroeder

John W Robinson

Brian N Wilcox

Billy J Whittington

A method and apparatus for memorizing and playing back an accompaniment passage in an electronic organ wherein the keyboard is multiplexed to develop a serial input data stream having keydown signals in the time slots corresponding to the depressed keys, selectively writing into a programmable random access memory data corresponding to the absolute address of the first occurring keydown signal in the pulse train and then writing into the memory data corresponding to the intervals, expressed in terms of time slots in the multiplexed data stream, between a number of the first occurring keydown signals, beginning with the first occurring signal. The data is read out of the memory and converted to a serial time division multiplexed data stream by means of comparators which produce a pulse each time there is a compare condition between the output of the memory and the count produced by the master counter/subcounter. The serial data stream is then demultiplexed so as to isolate the appropriate keyers to produce the tones selected by the keys depressed during the record mode.

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Ferdinand, IN, United States of America

Melvin J Schroeder