In 1957 I was an undergraduate Physics major at the University of Pennsylvania. One day ... and it continued for months ... there was a lot of construction going on under the Physics building. I was, of course, curious, and watched over time as a UNIVAC I was installed (Serial number #37).

Somehow I ended up as a research assistant working with the UNIVAC I, and, over the course of time, worked with Grace Hopper, John Mauchley, Tolly Holt, and Bill Turanski from UNIVAC, as well as with Saul Gorn, who was the person in charge of the computer center.

In 2000 I decided to write a simulator for UNIVAC I and UNIVAC II. I formally requested permission of UNISYS to use their copyrighted material, and was given permission in a very strange letter from their legal department that said, in effect, "Sure, go ahead, but for goodness sake why?".

So I did.

In the process of doing this I e-met a chap (who prefers to remain anonymous) who is arguably the last person ever to have operated a UNIVAC I, and whose vocation was repairing UNIVACs. Thanks to him the simulator is accurate very nearly to the bit level (to the extent that means anything on a word-oriented decimal machine!). In particular, some of the then-well-known test programs, that had been written by UNIVAC and by Betty Holberton of the David Taylor Model Basin run correctly on the simulator.

The simulator is available as a free download at Simtel,and if you register it (for $35.00) you'll get the current, updated, version.