[bsk]

>> So useful, in fact, every digital computer you see in front of you is a direct descendant of Mauchly's labor, not Atanasoff.

This doesn't make any sense. Atanasoff had some pretty genius ideas and together with Berry built the first electronic digital computer. Mauchly visited their lab, got a ton of information on ABC and later built another electronic digital computer - ENIAC, which was generally ABC 2.0.

[scott_s]

ABC was not a general purpose computer - it was not Turing Complete. It was not in continuous development by the time Mauchly saw it - that was the end of the line for the ABC. Eckert and Mauchly, on the other hand, developed a general purpose electronic computer with the explicit goal of getting it out to as wide an audience as possible.

[bsk]

Hmmmm, IMHO every statement here is incorrect.

Do you have a mathematical prove that ABC is not Turing Complete? I suspect that if one is sufficiently smart, he can implement a Turing machine on top of any 1930s, 1940s computer.

BTW I don't think 'General purpose computer' is used widely as equivalent of a 'Turing complete computer'.

From https://secure.wikimedia.org/wikipedia/en/wiki/John_Vincent_... : "In June 1941 Mauchly visited Atanasoff in Ames, Iowa for four days, staying as his houseguest. Atanasoff and Mauchly discussed the prototype ABC, examined it, and reviewed Atanasoff's design manuscript. Up to this time Mauchly had not proposed a digital computer. In September 1942 Atanasoff left Iowa State for a wartime assignment as Chief of the Acoustic Division with the Naval Ordnance Laboratory (NOL) in Washington, D.C. ... Mauchly visited Atanasoff multiple times in Washington during 1943 and discussed computing theories, but did not mention that he was working on a computer project himself until early 1944.

By 1945 the U.S. Navy had decided to build a large scale computer, on the advice of John von Neumann. Atanasoff was put in charge of the project"

Sounds to me like Mauchly just tried to steal Atananasoff ideas (with some success).

[calceranog]

Please simply compare the features of the ENIAC with the ABC, and tell me where the similarity lies: ABC operated in binary, while ENIAC was decimal. ABC used vacuum tubes as flip-flops, making it essentially an electro-mechanical machine operating at one operation per second. ENIAC used vacuum tubes as electronic counters, making it operable at electronic speeds, i.e., 5,000 operations per second. ABC was designed to process one type of problem (differential equations), while ENIAC was indeed general purpose, and could be programmed to handle any problem, including the insanely complicated mathematics of the hydrogen bomb. If you want to fault Mauchly for talking with other scientists while planning his own computer, then please also include all the other scientists with whom he shared ideas. Also note that the two met when Atanasoff attended a lecture Mauchly was giving ... on the use of electronics in computation. Does this sound like Mauchly got all his ideas from Atanasoff? Also, BTW, Mauchly kept "visiting" JVA's lab at NOL because HE WAS HIRED BY THE NOL TO CONSULT ON THE PROJECT because it was making very little progress under Atanasoff's direction. Look it up.

[scott_s]

The ABC not being general purpose (a term I use because it was used often in the book I referenced) is common knowledge. From it's Wikipedia page: "Conceived in 1937, the machine was not programmable, being designed only to solve systems of linear equations." http://en.wikipedia.org/wiki/Atanasoff%E2%80%93Berry_Compute...

I suggest you read the book I referenced - the relationship with von Neumann was not straight forward, either. Mauchly clearly did get ideas from Atansoff - but the ENIAC was not just a straight copy of ABC. Eckertt and Mauchly innovated as well - as much as we expect anyone to when we say they "invented" something.