This paper describes a microcomputer interfacing course for computer science students. Students build simple logic circuits to interface a microcomputer with real-world devices, such as stepper motor and digital displays, and program the computer to monitor and control these devices. Programs are written in Pascal and assembly language. The emphasis is placed on applications rather than on theory. This course is especially designed for computer science students who are proficient in software programming but have little or no experience in electronics. The experiments described here have been developed on the Apple ft microcomputer, but they can be easily adapted to other microcomputers.