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From: sxr@cs.purdue.EDU (Saul Rosen)
Newsgroups: comp.arch
Subject: Re: Re: Mercury delay lines
Message-ID: <11001@medusa.cs.purdue.edu>
Date: 6 Jul 90 18:28:21 GMT
References: <3040@softway.oz> <2694@wrgate.WR.TEK.COM> <1990Jun7.210822.5230@esegue.segue.boston.ma.us> <2701@wrgate.WR.TEK.COM> <1317@m1.cs.man.ac.uk> <645274007.10856@minster.york.ac.uk>
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Reply-To: sxr@babbage.cs.purdue.edu (Saul Rosen)
Organization: Department of Computer Science, Purdue University
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In article <645274007.10856@minster.york.ac.uk> martin@SoftEng.UUCP (martin) writes:
>>The Manchester University Mark I machine was the first stored program
>>machine to run.  It first executed a program correctly (to compute
>>greatest common factors) on 21st June 1948 
>>
>Yes, but although it was perhaps less general, both these machines
>post-date the Colossus, which was running, decoding the German Top
>Secret Navy Code (amongst others?) during much of the Second World War,
>and therefore BEFORE 1945!
>
>Unfortunately many details of Colossus are sketchy, not least because
>some parts are still (I believe) classified Top Secret!! (At least
>this certainly was the case in the mid 1980's)

The Volume 5 Number 3 (July 1983) issue of the Annals of the History
of Computing has a special feature entitled "Colossus at Bletchley Park."
It contains several excellent articles that discuss the Colossus in
a great deal of detail.  The cryptanalysis work for which it was
built is still classified, but the machine itself is not.  

The Colossus was years ahead of anyone else in the successful use of
electronics in a large scale special purpose computing system.  The
first Colossus system that was in operation in December, 1943 had 1500
vacuum tubes (valves in England.) However the Colossus was not a
general purpose computer.  I don't think anyone questions the fact
that the ENIAC was the first electronic general purpose computer.  The
Colossus  was certainly not a stored program computer, and it
certainly did not store programs in delay line memory.  

Most people give Maurice Wlkes' EDSAC at Cambridge University 
credit for being the first stored program computer that actually ran
real programs, which it did in May of 1949.  The initial design of the
EDVAC at the Moore School was done in 1944 and 1945, but the EDVAC
did not become operational until much later. The Manchester Mark I
does have a reasonable claim for being first, but it can be argued
that it was a minimal computer, a prototype that could only run simple test
programs. Some people at Univac have  claimed that they have evidence
that proves that Eckert and Mauchly's BINAC was running even earlier
than the EDSAC and that it deserves credit for being the first
running stored programm computer.  
computer that actually ran useful programs.