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From: dc@cs.qmw.ac.uk (Daniel Cohen)
Newsgroups: comp.arch,sci.logic,comp.theory
Subject: Re: What were real machines which helped Turing?
Message-ID: <3257@sequent.cs.qmw.ac.uk>
Date: 16 Jan 91 13:18:20 GMT
Followup-To: comp.arch
Organization: Computer Science Dept, QMW, University of London, UK.
Lines: 28

The background to Turing's work is well discussed
in the book: "Turing: the enigma of intelligence",
I think it's by Hodges ( e-mail me if you want a
proper reference; it's at home ).

The gist of the answer would be that the concept of
the Turing machine did not derive from any actual
computing devices, but from a generalisation of how
a human being does computation - essentially, by
looking at pieces of paper ( squares on a tape ),
and adjusting context accordingly ( changing state
). This approach came about because Turing was
interested in the famous Hilbert problem ( one of
23 ) concerned with the decidability of
mathematical questions.

Of course, that doesn't mean that Turing was
uninterested in the practicalities of mechanical
computation; he had an interest in analogue
computers and was later the leading light behind
the ACE. But I believe that the foundations for his
work were mathematical, not practical computers.

-- 
Daniel Cohen              Department of Computer Science 
Email: dc@cs.qmw.ac.uk    Queen Mary and Westfield College
Tel: +44 71 975 5249/4/5  Mile End Road, London E1 4NS, UK
Fax: +44 81 980 6533      *** Hit the North!!! ***