Posts tagged with “Jim Stutsman”

The Percom Doubler

The Percom Doubler was the first successful double-density add-on for the TRS‑80 Model I. It was introduced in 1980 by Percom Data Company for an initial price of $219.95. The Doubler hardware was designed by Wayne Smith and Harold Mauch (president of Percom) and the accompanying software was written by Jim Stutsman.

An Interview with Jim Stutsman

I recently had the opportunity to interview Jim Stutsman, whose works include MICRODOS and DBLDOS for Percom and Monte‚Äôs Windows for Montezuma Micro. In the interview, conducted in October 2008, he had some very interesting answers to my questions and provided some fascinating insight into the early days of the TRS‑80.


MICRODOS, later known as OS-80, was the only TRS‑80 disk operating system that made no attempt at TRSDOS compatibility. It was written by James W. Stutsman and released by Percom in 1979. Rather than using a command shell like Model I TRSDOS, MICRODOS used extensions to BASIC. It implemented most of the Disk BASIC commands added by TRSDOS. Also unlike the other operating systems, MICRODOS had no file system. All disk accesses were made using the starting sector and length.