Useful ideas for microcomputer operating systems

Microprocessor applications fall into two classes: general purpose computer systems as are found in home and hobby computers, and special applications where the microprocessor is dedicated to a single task as in microwave ovens and medical instruments. General purpose operating systems are too big and too complicated to be appropriate for use in a special purpose application. However, some operating system services find widespread use in a variety of dedicated microprocessor applications.This paper describes three generally useful ideas for special purpose microcomputer operating systems: a system stack, a timer controller, and a keyboard handler. A device based on a Texas Instruments TMS 9980A 16 bit microprocessor (1) is presented to illustrate these ideas in a dedicated data collection system.