> As head of the mathematics division of the British National Physics Lab,
> [J.R. Womersley] hired Alan Turing in 1945 to design an all-purpose stored
> program electronic digital computer. Biographical information about
> Womersley would be very much appreciated.
Quite a bit of the history of computers is implied in this short message.
In 1945 no operating electronic computer existed. (The ENIAC was not finished
until 1946). The stored-program electronic computer was even further in the
future. It is generally considered that the first stored-program computer
was the EDSAC, built at Cambridge University in England and operational in
1948, although IBM's SSEC (Selective Sequence Electronic Calculator), which
became operational around the end of 1947, may have preceded it. (The EDSAC
however was pure electronics, whereas the SSEC was "a wierd gigantic hybrid
of electronic and mechanical parts, half modern computer and half punch-card
machine...with 12,00 [vacuum] tubes and 21,400 mechanical relays." (Thomas J.
Watson Jr. _Father Son & Co._ New York: Bantam, 1990, page 190)).
Womersley and Turing, therefore, set out in 1945 to build not just an
electronic computer, at a time when electronic computers did not yet exist,
but a computer that was a generation ahead of anything being built at the
time.
Turing quit the project in frustration in 1948. The computer, known as the
"ACE" ("Automatic Computing Engine", a title adapted from Babbage) became
operational in 1950 (it is now in the Science Museum in Kensington). About
30 copies, known as DEUCEs, were built, making it one of the most popular
computers of the early 1950's.
Who invented the stored-program computer? Most books credit von Neumann, and
the concept is generally referred to as a "von Neumann machine". However,
the original Turing machine was a stored-program computer (and could have
been built using the electronics technology of 1945, had anyone wished to do
so). Turing seems to have developed the stored-program ideas of the ACE in
advance of and independently of von Neumann.
Watson unfortunately does not give the lineage of the SSEC. There was one
other inventor, Konrad Zuse in Germany, whose work in designing programming
languages implies that the computers he designed and built used stored
programs.
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One other advance in computer architecture was needed to create the modern
computer, and that was the invention of an interrupt system. I can't find
any written sources on this invention, but I have been told that it first
appeared on the "Ferranti" computer built at the University of Manchester in
England (and apparently operational in 1949, judging by the appearance of an
article describing it in _Nature_ vol 164 ppl. 648-687 (Oct. 22, 1949)).
So...the first electronic digital computer (the ENIAC) was built in the US,
but the highly significant EDSAC and Ferranti computers were built in
England. Turing and Womersley's DEUCE was a best-seller in the early
1950's. It seems safe to say that circa 1950 British computers were at least
comparable to US computers and frequently superior. In other words, Britain
circa 1950 was leading the US in computers.
And just when did the US overtake Britain in computers? Circa 1954, or just
about the time of Turing's death. Coincidence? Probably, but sometimes you
wonder.
James A. Landau