[ECKERT, J, Presper (1919–1995), FORRESTER, Jay W. (1918–2016), HOPPER, Grace Murray (1906–1992), MAUCHLY, John (1907–1980), TURING, Alan (1912–1954), et al.]; HARVARD COMPUTATION LABORATORY

Proceedings of a Symposium on Large-Scale Digital Calculating Machinery

Harvard University Press, Cambridge MA, 1948

Quarto; pp. [xxx], 302. Near fine condition: top and bottom of spine very slightly bumped; small ownership stamp to front free endpaper (mathematician W.F. Freiberger)

An important record of one of the earliest conferences on electronic digital computing, with numerous contributions to discussions from Alan Turing, alongside papers and other discussion points by luminaries such as John Mauchly, J. Presper Eckert, Jay W. Forrester, and Grace Murray Hopper.

The Harvard Symposium on Large-Scale Digital Calculating Machinery took place during January 1947, and was organized by Howard Aiken at the Harvard Computation Laboratory. The symposium brought together virtually all the leading figures of the young field—designers of the Harvard Mark I and II, ENIAC, and Bell Labs relay machines, as well as academic and industrial researchers from the us and Britain. Detailed technical papers were presented on architecture, storage, and applications, for instance in economics, physics and pure mathematics. These published proceedings offered the first widely available overview of the state of digital computing in the immediate postwar years, and shaped how both government agencies and universities perceived the computer – not just as a military calculator, but as a general-purpose scientific and business tool.

At the time of the symposium Turing was working on the British government-sponsored Pilot ACE machine, and his comments on the underlying conception of the Pilot ace ACE (as always) very revealing:

We are trying to build a machine to do all kinds of different things simply by programming rather than by the addition of extra apparatus. Without going into the details of the machine, I am afraid I cannot really state quite what happens, but I can give a very rough outline. We have in the machine a number of flip-flop circuits which are used to store one digit at a time. Therefore, I suggest that this type of device can be used for recording on wire. We are not actually planning to use wire, so that I have to make up this method on the spur of the moment. Suppose I have the wire and recorder as in [the figure in the preceding paper], and instead of a pulse former I have simply a flip-flop in which I can store a single digit at any moment. That is to say, I can set the flip-flop either into the one stable position or the other, and in the one position it will be recording a one, and in the other position it will be recording a zero. In other words, the flip-flop is one of the places to which pulses can be delivered. Then we simply use the full computing facilities of the machine to select from the delay line storage whichever pulse we want to record at any particular moment, deliver it to the flip-flop, and then record it on the wire. The flip-flop and recording head are allowed to operate for the required period of time, 200 microseconds. During that 200 microseconds arrangements are made by the ordinary computing techniques to pick out the next pulse that one desires to record. And so it continues. This is an application of the general principle that any particular operation of physical apparatus can be reproduced within the EDVAC-type machine. Thus, we eliminate addition apparatus simply by putting in more programming. (pp. 272–3, response to C. Bradford Sheppard’s paper ‘Transfer between External and Internal Memory’)

This shows Turing to be at the vanguard of computing design, as he proposes solving hardware design problems through programming. At this time most computing groups were more willing to build purpose-built I/O and control circuits for each memory technology. Turing’s insistence that a stored-program machine should control its own peripherals and even substitute for missing hardware was unusual. Turing’s idea that ‘apparatus can be reproduced within the machine’ eventually became central to the philosophy of general-purpose computing: you can simulate or control arbitrary processes in software.

Other important contributions include:

• George Stibiz on ‘The Organization of Large-Scale Computing Machinery’

• Jay Forrester on ’High-Speed Electronic Storage’

• Herman Goldstine on ‘Coding for Large-Scale Calculating Machinery’

• John Mauchly on ‘Preparation of Problems for EDVAC-Type Machines’