A Statement from John Hudson

John Hudson

JH = John Hudson
GAM = George Michael

GAM: One of the sadder aspects of these war stories is that I was unable to get to certain persons before they passed away. Here is a statement by John Hudson, prepared even before he knew he was going to be interviewed. He died while this project was being formed. John was one of the first Livermore programmers; quiet, gentle and a prodigious producer.

Statement of John Hudson, November 29, 1989

JH: When I first started (at the Lab), I was assigned to the UNIVAC computer group. I worked on several things; Neutronics codes (programs) using the Monte Carlo method, developing utilities for mathematical subroutines, molecular dynamics, and some exposure to Hydrodynamic methods. The codes were written in machine language when there was no floating-point hardware or index registers.

With the proliferation of computers over the next few years, I was assigned to the first compiler group at the Lab, and was involved with writing a compiler for the IBM 704. When it was completed, I worked on some hydrodynamics programs using both our compiler and the first versions of FORTRAN. I also wrote subroutines and utilities for the IBM series of computers, the 704, 709, 7090, and 7094.

I was next assigned to write programs for the UNIVAC LARC where I coded special heat flow programs using the Monte Carlo method. I also produced other mathematical routines and utilities and special input-output programs for devices such as the CalComp incremental plotters and the LARC Electronic Page Recorders (EPRs) for film recording.

My next big assignment was as a group leader for the Nuclear Test Division computer support group. This group grew over seven or eight years from one to 16 programmers. My function in this position was to decide which person was to be assigned to which programming job. The tasks were very diverse, each requiring some sort of specialty. Anything from chemistry, or mathematics to file management. I was always involved with the overall design of the slate of programs used by the entire division. The major project which I did for EG&G was to develop a mini-computer-based control and monitoring system for test area procedures at the Nevada Test Site. It sent control signals and monitored data over microwave communication links and provided dialog with test monitors as well as direct memory access, and servicing several local input-output devices. This work made use of a Varian 620I ruggedized machine that included every hardware option available from Varian. We wrote the program in assembly language, and assembled on one of the computers based within the Livermore Time-Sharing System, because it took far too long to assemble on the 620I.

During this period I was also involved with devising methods for utilizing large blocks of idle time on the main frames with the time sharing system. This involved the management of very large programs having only low priority, running only in background mode. The value of these strategies was shown best by the improvements in system efficiency.