Dusty Decks: Preserving historic software

A day in the life of an IBM Customer Engineer, circa 1959

I’ve added another important document to the Fortran I/Fortran II collection at the Computer History Museum:

This document is filled with useful information for anyone interested in digging into the IBM Fortran I/II compiler, and provides fascinating hints about what it was like to be a customer engineer in the late 1950s. It begins with an introduction to the nature of machine language, assembly language, and higher-level languages, starting with an analogy whose exposition would not be considered quite politically correct today: “The problems involved in man’s communications with the complex computer are in many respects similar to those problems involved with his communications with another man who speaks an unfamiliar language.” The next chapter jumps right into the structure of the compiler with summaries of each of the sections (passes). This is followed by a description of the Fortran systems tape, which performed the functions we now associate with an operating system. Section 1.12.00, Service Aids, notes: “To successfully run the Fortran translator the 704 must be in in prime working order. The tape system in particular, and the drum are given a good work-out during the exeuction of the program.” It goes on to list adjustments and engineering changes that were likely to be required to run such a demanding program as the Fortran compiler. Another chapter describes the various tables used to represent the intermediate and final object program.

I was able to scan this document courtesy of Mark Halpern, whose first assignment after joining the IBM Programming Research Department in 1957 was to study and document (via flow-charts) the Fortran compiler. Mark’s memoirs were published in three parts in the Annals of Computer History starting in 1991; eprints are available online at Mark’s web site.

Postscript (March 20, 2006): I should have noted a fascinating memoir by John Van Gardner, who was one of the IBM Customer Engineers who installed IBM 704 serial number 13 at Lockheed Aircraft in Marietta, Georgia in May 1956. This memoir describes the resourceful techniques he used in 1957 to debug a hardware problem that resulted in the Fortran compiler behaving in a nondeterministic manner.

[Edited 10 May 2014: community.computerhistory.org/scc => www.softwarepreservation.org; 2 Jan 2016: substituted Internet Archive link for Mark Halpern’s web site.]