Turing, von Neumann, Colossus, and influences

Some bits of interest, from the 1976 “Woodstock” talk The COLOSSUS by Brian Randell… from the 36 minute mark, some comments about Turing, and about von Neumann, and who influenced whom…

…the explanatory caption states that Turing’s earlier work had its full influence on the design concept of the Colossus.

Questions of influence are very hard to assess.

Turing clearly was viewed with considerable awe by most of his colleagues at Bletchley, because of his evident intellect and the great originality and importance of his contributions there, and by many with considerable discomfort because his personality was so outlandish. Many people found him incomprehensible, but all of the Post Office engineers who worked with him say that they found him very easy to understand. Their respect for him was immense, though as Chandler said the less said about him as an engineer the better.

Turing seems to have worked on a wide variety of mathematical topics during this period, and in fact a very important statistical method he developed then was rediscovered and developed further later by Abraham Wald, and is now known as sequential analysis.

The early projects that the Dollis Hill people did were in close cooperation with Turing. His work on computability was well known and virtually all of the people i’ve interviewed recollect wartime discussions of his idea of a universal automaton.

[Tommy] Flowers incidentally also recalls lunchtime conversations with Newman and Turing about Babbage and his work.

[Jack] Good has written that Newman was perhaps inspired by his knowledge of Turing’s '36 paper, however Newman’s view now is that, although he and his people all knew that the planned Colossus was theoretically related to a Turing machine, they were not conscious of their work having any direct dependence on these ideas or those of Babbage, and Turing was not directly involved in Colossus or any of the meetings on Colossus.

[38mins] The one other aspect of Turing’s role that I would dearly like to clarify is his reputed wartime meeting with von Neumann.

The story, or rather the legend, is that the meeting was of critical importance to the development of the modern computer.

The written paper summarizes a little more that I found out about Turing’s visits to the States and von Neumann’s visits to Britain. However for my part I’m now disinclined to believe the legend, though I think the situation was probably summarized well by Stan Frankel when he wrote:

Many people have acclaimed von Neumann as the father of the computer in a modern sense of the term, but I am sure that he would never have made that mistake himself.

He might well be called the midwife perhaps, but he firmly emphasized to me, and to others I am sure, that the fundamental conception is owing to Turing, in so far as not anticipated by Babbage, Lovelace, and others.

In my view von Neumann’s essential role was in making the world aware of these fundamental concepts introduced by Turing, and of the development work carried out in the Moore school and elsewhere.

Both von Neumann and Turing of course also made substantial contributions to the reduction to practice of these concepts.

There is a chapter in my paper about the American scene and there is no time to go through that, other than to summarize that Flowers and his colleagues did not learn about any of the American work on electronic or electromagnetic digital computers such as at Bell Labs, Harvard, Iowa State, IBM, MIT, or the Moore school until close to or after the end of the war.

it’s unclear to what extent scientists and engineers working at the Bell Labs, IBM, and elsewhere in the States on problems similar to those that Flowers was working on were in touch with the work of Flowers and his team. But there’s no evidence at all of any American involvement in the design of Colossus.

Although special purpose machines were being developed in the states during the war as is the case with Colossus they are not as yet fully declassified however my correspondents were able to provide me with some details of the American work, enough I believe to put Colossus in a particular in a proper perspective.

And there are several pages in the written paper summarizing the work on these special purpose devices by people such as Vannevar Bush, John Howard, Arnold Dumey and Sam Williams of Bell Labs

My information is that there were no earlier or contemporary electronic machines in the American communications operations which matched the size or complexity of Colossus.

The statements i’ve received from both sides of the Atlantic concerning the Colossus indicate that it had no rivals or precedence as a programmable electronic computer, and that there were no links between it and the ENIAC project.

I am pretty well certain that ENIAC received no advantage whatsoever from the work that was done on Colossus.

Brian Randall’s webpages are here. I can’t find an online copy of his paper, which is part of the volume by Metropolis etc.

I’m generally under the impression that this talk (by Brian Randell) has held up rather well. Is there anywhere a comprehensive lists of later comments, an overview of what had to be rectified as more information became available or if there were significant gaps that would have distorted the historical events?

There’s a bit at the end of the talk about ACE, and EDSAC, which I could perhaps have transcribed too, but I ran out of steam.

I think some of the statistical techniques from the day were classified until quite recently: Brian notes that some of the legends in the photos of the machine are illegible, and I suspect he means they are redacted.

Perhaps see also Copeland’s book and website:
Colossus: The Secrets of Bletchley Park’s Codebreaking Computers