A small-scale operating system foundation for microprocessor applications

Sound engineering methodology, which has long been valued in hardware design, has been slower to develop in software design. This paper uses a case study of a small real-time system to discuss software design philosophies, with particular emphasis on the abstract machine view of systems. It demonstrates how the currently popular software design axioms of generality and modularity can be used to produce a software system that meets severe space constraints while remaining relatively portable across a family of microcomputers. These sorts of constraints have often been used to justify ad hoc design approaches in the past. The results of the project suggest that the use of such techniques actually make the meeting of many constraints easier than would a less organized approach. In addition, the reliability and maintainability of the resultant product is likely to be better.