Electronic musical instrument

Abstract

An electronic musical instrument has input elements such as tone selector keys and control knobs which send input signals representing desired tone parameters to a primary computer. The primary computer, which includes a primary microprocessor and a primary memory, is connected with several voice modules and several effect-producing modules by means of a primary bus. Each voice module has a plurality of tone outputs for generating different tones. The tones for each voice module are produced by a respective subsystem including an auxiliary microprocessor, a clocking device and a digital-analog converter unit which are connected by an auxiliary bus. The auxiliary bus is connected with the primary bus via a bus switch. An auxiliary memory belonging to the subsystem is connected with the bus switch which permits the auxiliary memory to alternately communicate with the primary bus and the auxiliary bus. The subsystem further includes a sequencer which is driven by clocking signals generated by the clocking device. By using an auxiliary microprocessor and an auxiliary memory to create the tones, the workload of the primary microprocessor may be reduced and it becomes possible to generate a relatively large number of acoustically satisfactory tones simultaneously with relatively little added expense.