Nearly all electronic instruments turned out in recent years have been equipped, with the microcomputer, which have such. features as simple circuit, excellent stability and automatic data processing.

In order to improve the property price rate of intelligent instruments, reduce volume and weight, this paper introduces a new method of running two monitor programs in a singlechip microcomputer.

Making up Musical Instruments with microcomputer is the one of microcomputer applications. It also is the interesting form for learning microcomputer operation.