Abstract: The VMS-Ⅲ System is designed to perform not only all those functions that can be provided by the existing stimulators such as digital stimulators,program controlled stimulators and others,but also additional functions.The user can program the system ot vary the amplitude and width of the output pulses or to change the output Waveforms.It has two separate output channels each subdivided into four output terminals.The System is composed mainly of a stimulator proper,of which the core is a Z₈₀-CPU microprocessor and two photo- electric isolation units,of which the output drift is corrected with a self-correction technique to approach zero drift resulting in stable and precise outputs.The System has been continually in use for nearly two years without malfunction.It should serve as a valuable tool for medical research and for clinical diagnosis.

Key words: computers, microcomputers, electric stimulation/instrumentation, equipment design