The story of how the Colossus computer at Bletchley Park aided the allied code-cracking effort during World War II is becoming well known. Its claim to be a forerunner of modern-day computers is also well established.
What is much less well known is the tale of how Colossus's story came to be told in the first place. It is a tale of how one man's dogged efforts overcame official secrets and official indifference to rewrite computer history.
Computer scientist Brian Randell was the man who started uncovering the history of Colossus.
That history had to be prised out of the archives because official efforts to cover up its success worked so well. Thousands of people worked in the huts at Bletchley Park during WWII on code-cracking but only a handful were involved with Colossus and fewer still knew everything about it. All those codebreakers signed the Official Secrets Act which demanded that they kept quiet about their wartime career.
Almost all the machines were broken up once they ceased to be useful and design documents were burnt or destroyed at the same time.
I got to know more about it than they did, Prof Randell told the BBC. They were so compartmentalised that those who worked in one hut would not dream of talking to people in another hut. Prof Randell detailed his experiences of uncovering Colossus' history during a talk at The National Museum of Computing at Bletchley Park.
Sensitive operation
Prof Randell tripped over the story of Colossus in 1970 while preparing an academic paper on a little-known Irish computer pioneer Percy Ludgate who, in 1908, completed the design for a nascent computer.
Because he had a lot of material left over after writing about Ludgate, Mr Randell decided to use it as the basis of a series of papers dealing with early computers.
