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Turing and von Neumann: two founding fathers of the
computer age
Probably Turing’s greatest peacetime achievement was the proposal of two closely related
technological ideas on which modern computing is based: his twin concepts of the universal
computer and the stored program. Yet historians of the computer have often found Turing’s con-
tributions hard to place, and sadly many histories of computing written during the did decades
since his death did not so much as mention him.
Even today there is still no real consensus on Turing’s place in the history of computing. An
article published in 2013 by the editor of the Association for Computing Machinery’s flagship
journal Communications of the ACM objected to the claim that Turing invented the stored-
program concept.^23 The article’s author, my good friend Moshe Vardi, dismissed the claim as
‘simply ahistorical’.
Vardi emphasized that it was not Turing but the Hungarian–American mathematician John
von Neumann (Fig. 6.3) who, in 1945, ‘offered the first explicit exposition of the stored-program
computer’. This is true (see Chapter 20), but the point does not support Vardi’s charge of his-
torical inaccuracy. Although von Neumann did write the first paper explaining how to convert
Turing’s ideas into electronic form, the fundamental concept of the stored-program universal
computer was nevertheless Turing’s.
Von Neumann was actually very clear in attributing credit to Turing, both in private and
in public: it is unfortunate that his statements are not more widely known. He explained
in 1946 that Turing’s ‘great positive contribution’ was to show that ‘one, definite mecha-
nism can be “universal” ’, and in a 1949 lecture he emphasized the crucial importance of
Turing’s research, which lay (he said) in Turing’s 1936 demonstration that a single appro-
priately designed machine ‘can, when given suitable instructions, do anything that can be
done by automata at all’.^24 Von Neumann’s friend and scientific colleague Stanley Frankel
observed:^25
Many people have acclaimed von Neumann as the ‘father of the computer’ . . . but I am sure that
he would never have made that mistake himself.
figure 6.3 John von Neumann.
Photographer unknown. From the Shelby
White and Leon Levy Archives Center,
Institute for Advanced Study, Princeton.