|
|
|
|
|
|
Birth of the digital computer
Colossus was an electronic digital computer, built during WWII from over 1700
valves (tubes). It was used to break the codes of the
German Lorenz SZ-40 cipher machine
that was used by the German High Command.
Colossus is sometimes referred to as the world's first fixed program, digital,
electronic, computer. In any case, it was conceived before the American
ENIAC.
|
Colossus was designed by Tommy Flowers, an electronics engineer of the
Post Office Research Station (part of the General Post Office,
GPO) at Dollis Hill (UK), with input from Harry Fensom, Allen Coombs,
Sid Broadhurst and Bill Chandler.
It was used to solve a problem posed by Max Newman,
one of the Bletchley Park codebreakers.
The image on the right shows one of only eight photographs taken during
WWII of an original Colossus Mark II in action.
The photographs were used by Tony Sale
and his team of volunteers in 1993, to start the
Colossus Rebuild Project.
|
|
|
One of the most prominent parts of Colossus is the input device on the right,
nicknamed 'the bedstead'. It is an optical reader for punched paper tapes, than
can read data at the phenomenal speed of 5000 characters per second!
A complex system of supporting wheels is necessary to prevent the tape from
ripping apart at this speed.
|
Immediately after WWII, most Colossus computers were ordered to be demolished.
They were either destroyed or dismantled and the components were reused.
A few machines were kept for
future use, but eventually these were destroyed as well, as and when newer
technologies emerged.
|
In 1991, a team led by Tony Sale started playing with the thought that it
might be possible to rebuild a fully operational Colossus computer.
Eventually, in 1993, he set out to start the rebuild project, based on the
very limited information that he had gathered.
The first parts of Colossus were switched-on on 6 June 1996, in the presence
of HRH the Duke of Kent and the original designer Tommy Flowers.
The latter passed away in 1998 at the age of 92.
In November 2007, the rebuild project was completed and Colossus
was staged in an international Cipher Challenge contest.
|
|
|
Since then, work has started to convert Colossus (now called Colossus-I)
into Colossus Mark II.
As the Mark II version contains over 1000 more valves than the
original machine, this project would, no doubt,
keep Tony and his team busy for the next couple of years.
Sadly though, Tony Sale passed away
unexpectedly on 28 August 2011 at the age of 80, leaving behind
the Colossus legacy.
Luckily, his achievement was well-documented so that his
team can complete the work.
Below are some photographs of Colossus that we took in November 2004.
We apologize for the rather poor quality; at the time we were still using
an analog camera.
|
It is sometimes assumed, even by respected writers, that Colossus was used
to break the German Enigma codes. However, this was
not the case. Colossus was only used to break the codes of the far more
advanced Lorenz SZ-42, used by Hitler's High
Command (Oberst Kommando des Heeres).
|
Enigma was instead broken with help of an electro-mechanical machine,
called the Bombe,
designed by Alan Turing and Gordon Welchman at Bletchley Parkand built by
Harold (Doc) Keen at the British Tabulating Company (BTC).
Over 200 of these machines were installed at Bletchley Park and its
outposts, attacking the German Enigma messages on a daily bases.
 More information
|
|
|
|
|
|
|
Any links shown in red are currently unavailable.
If you like this website, why not make a donation?
© Copyright 2009-2013, Paul Reuvers & Marc Simons. Last changed: Thursday, 06 December 2012 - 13:22 CET
|
 |
|
|
![Tony Sale in front of Colossus. Copyright South Beds News [4].](img/tony_sale_full.jpg "Tony Sale in front of Colossus. Copyright South Beds News [4].")
