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From: aa1@j.cc.purdue.edu (Saul Rosen)
Newsgroups: comp.arch,sci.logic,comp.theory
Subject: Re: What were real machines which helped Turing?
Message-ID: <11711@j.cc.purdue.edu>
Date: 23 Jan 91 17:13:34 GMT
References: <12623@hubcap.clemson.edu> <1991Jan16.165251.3783@sctc.com> <1991Jan19.234454.26225@eecs.wsu.edu>
Reply-To: sxr@babbage.cs.purdue.edu (Saul Rosen)
Followup-To: comp.arch
Organization: Purdue University
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In article <1991Jan19.234454.26225@eecs.wsu.edu> pcooper@yoda.UUCP (Phil Cooper - CS495) writes:
>In article <1991Jan16.165251.3783@sctc.com> smith@sctc.com (Rick Smith) writes:
>>steve@hubcap.clemson.edu ("Steve" Stevenson) writes:
>>
>>> The Atansoff computer was probably known to Alan Turing.
>       ^^^^^^^^
>  I'm not 100% sure, but I believe the man's name is Atanasoff
>
>>
>>This is a fascinating statement, but your use of the word "probably"
>>implies that you lack hard evidence. Is there any evidence to support
>>this statement?
>>
Turing wrote his famous paper on computable numbers in 1935-36.  In it 
he introduced his conceptual computer that has come to be known as the
Turing machine. The Universal Turing Machine that he introduced in the
same paper can be considered to be a conceptual or even a mathematical
model of the real universal computers (e.g. the EDVAC) that appeared
about 10 years later. It is not clear whether Turing's ideas had any 
direct effect on the Edvac.  However, it is known that von Neumann knew
Turing while Turing was a graduate student at Princeton in 1937-39.

Atanasoff started to work on his machine, later known as the ABC computer
in 1937-38, and worked on a prototype in 1939.  I don't think it is at
all likely that Turing ever knew anything about the Atanasoff computer,
even after World War II when Turing designed the real hardware ACE computer.
The above dates show that Turing's work on computability preceded the work
of Atanasoff.  Note also that the Atanasoff computer was not a programmed
general purpose computer, and thus its concepts were in no way related
to the very general programming concepts introduced  by Turing in his 
1936 paper.

Saul Rosen