Two main application areas for high performance single-chip microcomputers concern mechanism control and arithmetic processing. Mechanism control applications involve the use of a microcomputer to govern a mechanical device or system, such as a line printer. Arithmetic processing applications deal with the manipulation of information, either for a closed loop control system or for a visual display; examples include a digital voltmeter or a proportional, integral, and differential servo controller. Typical program subroutines, developed in detail, demonstrate performance requirements in these two areas. Implementation of full-duplex serial input/output (I/O) communications is a typical device controller application. Simple mathematical routines, comprising binary multiplication and division, binary to binary coded decimal (BCD) conversion, and BCD to binary conversion, are used as examples of arithmetic processing. Algorithms for these programs are expressed in a machine independent design language which allows easy translation to another environment.