Looking back, what would you say was the significance of Turing’s 1936 entscheidungs-problem paper?

I always felt people liked to make a song and dance. Something like the doctrine of the Trinity involved whereas to an engineer you’ve only got to be told about the stored program idea and you’d say at once “That’s absolutely first-rate, that’s the way to do it.” That was all there was to know.

There was no distinction in that paper that had any practical significance. He was lucky to get it published at all but I’m very glad he did. I mean [Alon-zo] Churchl had got the same result by other methods.

I liked Turing; I mean we got on very well together. He liked to lay down the law and that didn’t endear him to me but he and I got on quite well. People sometimes say I didn’t get on with Turing but it’s just not true. But then I was very careful not to get involved.

 

Was he a difficult man with whom to get along?

Yes, I think that’s probably true and he was not in any sense a team leader. He didn’t know how to get things done.

Of course I had another advantage there. I had war service, six years of it, and I had done real staff jobs and that teaches you a lot about how to get things done. [Max] Newmanm was a great admirer of Turing. But he was not in the line management of the computing work; I mean Newman was never an engineer. The professor of electrical engineering did that.

 

[freddie] Williams?n

Yes, everybody at TRE [Telecommuni-cations Research Establishment] had some experience of management. Williams was in charge of the computer at Manchester and he was a very strong-minded person. Mind you he was a leader too—he ran it like a dictator!

You can’t design or build a computer unless you’re an engineer. I mean that’s what you mean by being an engineer. Newman exerted very little influence on what went on in Manchester. Williams saw to that all right.

 

l Alonzo Church (1903–1995) m Maxwell Herman Alexander Newman (1897–1984) n Sir Frederic Calland Williams (1911–1977)

Did Newman’s involvement with the colossus have any effect on developments at manchester do you think? No, I don’t think Williams would have been interested in the technology because, as I say, when technology moves, it moves very fast. And the technology that was used in the Colossus was very different from the sort of technology that took root in Bawdsey [radar station].

 

Was there any rivalry between the various computer-building projects about who would get there first? Well, as I always say, it was a funny race because we were all aiming at different finishing points. You see, we wanted something that was business-like and would fit into this existing digital environment. Eckert and Mauchly wanted to produce a commercially viable computer and I don’t quite know what Williams wanted to do. He had no permanent interest in computers. He wasn’t very interested in computers at all. He was interested in showing that CRT memory would work but I don’t think he had any interest beyond that and he handed it over to Kilburn who made very good use of it. Kilburn was a very, very great success.

 

What are your recollections of Kilburn? I knew him very well. Of course we were very good friends and we were both determined that we wouldn’t allow any Manchester-Cambridge rival-ries to show up in our groups and we achieved that on the whole, I mean we always had a high respect for each other. It could so easily have happened, you know. But it didn’t and that was due to Kilburn’s common sense really and mine. It was very important but I mean we were complimentary.

 

What was Kilburn’s interest in computers? He was interested in providing a computing service as I was.

 

Returning to Newman for a moment. We now know that in 1945, Newman took Willis-Jackson, who was William’s predecessor, to Bletchley Park to see the colossus. Did Newman ever discuss the colossus with you—

even in the most general terms? No, and I don’t think Williams would have been interested in the technology because, as I say, when technology moves, it moves very fast. And the technology that was used in the Colossus was very different from the sort of technology that took root in Bawdsey.

 

another important figure at manchester at that time was Patrick Blackett.o Did you have anything to do with Blackett? Blackett? Oh, I knew Blackett, he was always very nice to me. He said he didn’t know anything about computers and that was perfectly true. He was of an age. Above a certain age people are never really happy with computers.

 

he helped Williams and Newman though? Well, he was a busybody so he would be everywhere. He was very energetic and he knew how to get things done. He thought socialism was a great thing, whereas I thought socialism was a great mistake and indeed it was.

 

What have you found most surprising about the developments that have taken place in computers since 1949? Well, of course, it’s the speed. We had great vision, we saw that computers were going to be a big thing, not only for arithmetic calculation but in other things as well, business and whatnot. We had great vision but we could have no idea of timescale. For one thing, young men don’t but the other reason was of course we couldn’t see the coming of semiconductors. Now semiconductors have given us various things, small size, small cost, high power but the important thing they have given us is reliability. We used to pray for reliability—our prayer was answered. In my lectures on this sort of thing I say that it was St. Theresa who was credited with the remark that it is prayers that are answered that create more problems than those that aren’t!

 

o Lord Patrick Maynard Stuart Blackett (1897– 1974)