History of computing hardware: Difference between revisions

Revision as of 10:36, 16 November 2005

Revision as of 10:36, 16 November 2005

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==American developments==

In [[1937]], [[Claude Shannon]] produced his master's thesis at [[Massachusetts Institute of Technology|MIT]] that implemented [[Boolean algebra]] using electronic relays and switches for the first time in history. Entitled ''[[A Symbolic Analysis of Relay and Switching Circuits]]'', Shannon's thesis essentially founded practical [[digital circuit]] design.

In November of [[1937]], [[George Stibitz]], then working at [[Bell Labs]], completed a relay-based computer he dubbed the "Model K" (for "<b>k</b>itchen", where he had assembled it), which calculated using binary addition. Bell Labs thus authorized a full research program in late [[1938]] with Stibitz at the helm. Their [[Complex Number Calculator]], completed [[January 8]], [[1940]], was able to calculate [[complex numbers]]. In a demonstration to the [[American Mathematical Society]] conference at [[Dartmouth College]] on [[September 11]], [[1940]], Stibitz was able to send the Complex Number Calculator remote commands over telephone lines by a [[teletype]]. It was the first computing machine ever used remotely over a phone line. Some participants of the conference who witnessed the demonstration were [[John Von Neumann]], [[John Mauchly]], and [[Norbert Wiener]], who wrote about it in his memoirs.

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All machines at that date still lacked what came to be known as the [[von Neumann architecture]].

==Colossus==

[[Image:Colossus.jpg|thumbnail|right|Colossus was used to break German ciphers during [[World War II]].]]

During [[World War II]], the British at [[Bletchley Park]] achieved a number of successes at breaking encrypted German military communications. The German encryption machine, [[Enigma (machine)|Enigma]], was attacked with the help of electro-mechanical machines called ''[[bombe]]s''. The [[bombe]], designed by [[Alan Turing]] and [[Gordon Welchman]], after Polish ''[[bomba]]'', ruled out possible Enigma settings by performing chains of logical deductions implemented electrically. Most possibilities led to a contradiction, and the few remaining could be tested by hand.

The Germans also developed a series of teleprinter encryption systems, quite different from Enigma. The [[Lorenz SZ 40/42]] machine was used for high-level Army communications, termed "[[Tunny]]" by the British. The first intercepts of Lorenz messages began in [[1941]]. As part of an attack on Tunny, Professor [[Max Newman]] and his colleagues helped specify the [[Colossus computer|Colossus]]. The Mk I Colossus was built in 11 months by [[Tommy Flowers]] and his colleagues at the [[Post Office Research Station]] at [[Dollis Hill]] in London and then shipped to [[Bletchley Park]].

[[Colossus computer|Colossus]] was the first totally ''electronic'' computing device. The Colossus used a large number of valves (vacuum tubes). It had paper-tape input and was capable of being configured to perform a variety of [[boolean logic]]al operations on its data, but it was not Turing-complete. Nine Mk II Colossi were built (The Mk I was converted to a Mk II making ten machines in total). Details of their existence, design, and use were kept secret well into the 1970s. Winston Churchill personally issued an order for their destruction into pieces no larger than a man's hand. Due to this secrecy the Colossi were not included in many histories of computing. A reconstructed copy of one of the Colossus machines is now on display at Bletchley Park.

==Konrad Zuse's Z-Series==