Difference between revisions of "Colossus Computer"

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The Colossus is arguably the first digital computer in human history. Created during World War II in order to help decipher encrypted German messages sent by the Lorenz Cipher, it stands as both an influential, technological advancement as well as a singular creation unto itself. Although its creation spawned a technological revolution in terms of electronic computation, its existence remained secret for over 30 years. Unlike the majority of technological media, the Colossus Computer was built with a singular purpose in mind, achieved its goal, and was immediately destroyed. It was never re-appropriated for a new use, except perhaps as an historical object, as it has recently been 'restored' as part of a museum for World War II code breaking at Bletchley Park.

In this way, as a technological medium, the Colossus is both hugely influential and entirely unique. Its role as a translator of another medium, that of German code, is a position not seen easily today. Perhaps this is why the Colossus can be easily forgotten, but deserves acknowledgement and remembrance.

Life of the Colossus

Cryptography Before Colossus

A New Cipher, A New Problem

Mind of the Colossus

Max Newman

Max Newman was in charge of the Tunny-breaking team at Bletchley Park. This group would come to be named after him, the 'Newmanry.' The 'Newmanry's' function was "to work on machine attacks on Tunny, and it complemented the Testery, where hand and linguistic attacks were used" (Good 160). He was the main managerial force behind the creation and overseeing of Colossus (and the Heath Robinson before that). He deserved credit in the creation of Colossus mainly in this administrative capacity, as well as deciding to bring in the brilliant Tommy Flowers who, it will be discussed, was the main creative force behind building Colossus (Good 163).

COPELAND #5

Jack Good

Jack Good was a statistician summed to Newman's team to help build an electronic machine to aid in the decoding process. He had previously worked on the Enigma code-breaking and the construction of the Bombe, as well as the Colossus's immediate predecessor, the Heath Robinson machine.

PICTURE: COPELAND #8

According to Good, "one of the greatest secret inventions of the war was the discovery that ordinary teletype tape could be run at thirty miles per hour without tearing" (Budiansky 314). In many way, Good helped pave the way for mechanized aid in code-breaking. It wasn't until he received help from TommyFlowers that the Colossus would take form.

Bill Tutte

Bill Tutte is the man who broke the Tunny code before any machines were even involved. Using two streams of intercepted text, Tutte was able to figure out the entire structure and functionality of the Tunny machine (Lorenz Cipher) without ever having seen it. Granted this took months, and individual decipherings could possibly take weeks, making the translated text unhelpful. That is why the creation of the Colossus was taken up (Good 161).

COPELAND #4

Tommy Flowers

Tommy Flowers was a British Post Office electronics engineer working at the Research Station at Dollis Hill. He was recruited as an automaton specialist by the Government Code and Cipher School (GC&CS). Along with Jack Good, he worked on theories derived by noted mathematicians Alan Turing and J von Neumann that led to the production of the Colossus (Ratcliff 205).

PICTURE 41 FROM COPELAND

The biggest contribution to the Colossus construction from Tommy Flowers was the suggestion that the wheel patterns in the machine be generated electronically. In this way, there was no need for dual paper tape, and the issue that plagued the Heath Robinson machine, synchronization, was eliminated (Sale, 354). "Alan Turing contributed to the thinking in developing these machines, as did Max newman and several others, but an enormous part of the credit for designing Colossus, and all the credit for building it, goes to Tommy Flowers" (Copeland 192).

Body of the Colossus

Structure

In total, there ended up being ten Colossi computers, the original Mk 1 and Mk 2, and eight replications of the Mk 2. The Colossus was made up of eight racks, arranged in two rows of four. The racks were 90 inches high. Each bay, holding four racks, stretched about 16 feet across. In addition to the racks, there would be a paper tape handler at one end as well as a output typewriter at the other (Sale 355). PICTURE: SALE 356

The typewriter was a modified version of an IBM Electromatic Typewriter, common in the 1940s. These modifications, placed by Tommy Flowers and his team, allowed the typewriter to interface with one of the Colossi. The typewriters were capable of printing ten characters per second, a high rate of performance that was necessary to quickly complete deciphering (Cragon 99). PICTURE: CRAGON 99

How Colossus Worked

Input: Cipher text punched onto 5-hole paper tape, read at 5,000 characters per second (cps) Output: Buffered onto relays, typewriter Processor: Memory of 5 characters of 5-bits held in a shift register, pluggable logic gates, 20 decade counters arranged as 5 by 4 decades Clock Speed: 5 KHz, derived from sprocket holes in the input tape Vavles: 2500 (Sale 357)

In brief, the Colossus read intercepted, encoded text at 5,000 cps. The Colossus would 'read' the text multiple times and use a complicated Boolean function between the text and the wheel patterns used to encode it. Boolean functions are the basis of computers, registering results as either true or false based on the punched holes in the tape.

The Colossus was made up of, basically, an optical reader system, a master control panel, thyratron rings and driver circuits, calculators, shift registers, logic gates, counters, and printer logic (Sale 357). PICTURE: SALE 359

Shadow of the Colossus

Rebuilding

The Colossus rebuild project was begun by Anthony Sale and colleagues in July, 1994 as part of the opening of the Museums of Bletchley Park dedicated to the history of code-breaking in World War II. Some actual Post Office and radio engineers ended up taking part in the project. A basic functioning Colossus was finished by June of 1996, with Dr. Tommy Flowers in attendance for the 'switch-on' occasion (Sale 362).

The major purpose of the rebuilding of the Colossus and the opening of the Museums at Bletchley Park is an attempt at changing the conception that the American-made ENIAC was the first digital computer ever made. In fact, the Colossus was completed two whole years before the ENIAC was switched on in 1944, yet the knowledge and nature of its secret war origins and the immediate destruction of the devices following their use has led to the Colossus being forgotten in computer history. The tide is slowly turning, however, as more information and research is being revealed into the creation and implementation of the Colossus.

Meaning of the Colossus

Bibliography

Andresen, S.L. “Donald Michie: Secrets of Colossus Revealed.” IEEE Intelligent Systems. Vol. 16. No. 6

Budiansky, Stephen. Battle of Wits: The Complete Story of Codebreaking in World War II. New York, NY: The Free Press, 2000.

Cragon, Harvey G. From Fish To Colossus: How the German Lorenz Cipher was broken at Bletchley Park. 2003.

Copeland, B.J. “Colossus: Its Origins and Originators.” Annals of the History of Computing, IEEE. Vol. 26. No 4.

Copeland, B.J. Colossus: The Secrets of Bletchley Park’s Codebreaking Computers. Oxford University Press, 2006.

Good, Jack. “Enigma and Fish.” Codebreakers: The Inside Story of Bletchley Park. Eds. F.H. Hinsley & Alan Stripp. Oxford Univeristy Press, 1993.

Halton, Ken. “The Tunny Machine.” Codebreakers: The Inside Story of Bletchley Park. Eds. F.H. Hinsley & Alan Stripp. Oxford Univeristy Press, 1993

Hayward, Gil. “Operation Tunny.” Codebreakers: The Inside Story of Bletchley Park. Eds. F.H. Hinsley & Alan Stripp. Oxford Univeristy Press, 1993

Hinsley, F.H. “An Introduction to Fish.” Codebreakers: The Inside Story of Bletchley Park. Eds. F.H. Hinsley & Alan Stripp. Oxford Univeristy Press, 1993.

Ratcliff, R.A. Delusions of Intelligence: Enigma, Ultra, and the End of Secure Ciphers. New York, NY: Cambridge University Press, 2006.

Sale, Anthony. “The Colossus of Bletchley Park.” IEEE Review. Vol 41 Issue 2. 1995

Sale, Anthony E. "The Colossus of Bletchley Park – The German Cipher System." The First Computers: History and Architectures. Eds. Raul Rojas and Ulf Hashagen. Cambridge, MA: The MIT Press, 2000.

Wells, Benjamin. “Advances in I/O, Speedup, and Universality on Colossus, an Unconventional Computer.” Unconventional Computation. 8th International Conference, 2009.