Harry Huskey had been an engineer on the ENIAC, EDVAC, and ACE computers and worked in the UK with Alan Turing before designing the SWAC. Huskey joined the NBS Institute for Numerical Analysis in 1948.
And, so we wrote this code for structure searching on steroid molecules and fragments thereof and it was an extremely ponderous code, but it ran, you see. And, we did convince the patent office that this was the way to go, which subsequently they did do. But because the code was so ponderous it was something that we hoped you would never have to use. Well in those days the idea of something you that you hope you would never have to use was the H-bomb. So of course we called the code the “H-bomb” code. Well, some how or other the code sheets got misplaced and when it became known that the H-bomb code sheets had been misplaced, the FBI came in. And, of course it took a lot of explaining to explain that this had nothing to do with the H-bomb, it was just a name that we chose to use for the code sheets. But the Patent Office did benefit by this introduction of the use of computers for searching in chemical literature
(I mentioned SWAC in a recent post about improved prime factorising algorithms.)
This image of one of the Williams tubes the SWAC used for memory is interesting: I had no idea that these performed a sweep for active bits. (I guess, having always active spots makes calibration and testing easier?)
In 1952, a program for testing Mersenne numbers … planned and coded by the author … was carried out, with the cooperation of D. H. Lehmer and the staff of the I. N. A. My thanks are due especially to Emma Lehmer, who did various auxiliary computations, including checking some of the results obtained against earlier results. The program was first tried on the SWAC on January 30, and two new primes were found that day; three other primes were found on June 25, October 7, and October 9.
…
At that time, the total memory of the SWAC consisted of 256 words of 36 binary digits each, exclusive of the sign. For the Mersenne test, half of this memory was reserved for commands. … roughly speaking, the testing time was a minute for the first and an hour for the last of the five new primes. Each minute of machine time is equivalent to more than a year’s work for a person using a desk calculator.
via
This was the first program that Robinson had ever written, and it ran the very first time he tried it!
where we see this tabulation for The Age of Electronic Computers:
