A hypothetical computer to simulate microprogramming and conventional machine language

Abstract

Microprogramming is no generally available to programmers because it may involve modification of a machine's native language. A hypothetical computer can provide a simulator for microprogramming projects and add considerably to one's understanding of the subject of microprogramming and the concept of a multilevel machine. The classical text, Structured Computer Organization by Andrew S. Tanenbaum, contains a design for such a hypothetical computer. This paper presents an implementation of this machine with a user interface to permit development of microprograms as well as development of programs at the conventional machine language programming level. The user interface is similar to that of MS-DOS's DEBUG program. In addition to providing the basis for projects in Computer Architecture and Computer Organization classes, the simulator is being used as a simplified hypothetical machine in a Systems Programming class for the development of assembler, linker, and loader projects.