A brief history of the computer
With computers now commonplace in every home, workplace and pocket, Simon Handby traces the development of the technology that changed the world
WARGAMES
While various inventions led to some early analogue, non-programmable calculating machines, the next major advances took place immediately before and during the Second World War, most notably at the Bletchley Park code-breaking site. We looked in detail at Bletchley’s wartime role in issue 272’s feature (on this month’s cover disc if you missed it), but its achievements in unlocking German ciphers were made possible partly by the mathematical genius of the people working there, and partly by the brute-force number-crunching provided by the first true computers.
The brilliant mathematician Alan Turing is acknowledged as the father of computer science, but he’s often wrongly credited with developing Colossus; the world’s first programmable, electronic computer. In fact, Colossus was designed by Tommy Flowers and other Post Office research engineers to replace and improve ‘Heath Robinson’, a mechanical calculating machine used at Bletchley. Entering service in February 1944, the Colossus machines provided the calculating speed and power to rule out impossible Lorenz cipher settings – which hugely sped up breaking messages from the German high command.
ENIAC: huge numbers of valves made wartime computers massive, room-filling affairs
While Colossi operated electronically – their only mechanical system was the tape reader through which encrypted messages were input – their construction would be unrecognisable next to a modern PC. Their huge size was necessary in part due to the use of 2,400 big, hot and power-hungry thermionic valves for circuit switching. Valves were at the heart of other giant computers immediately after the war, with the American Army’s ENIAC ballistics computer having no fewer than 17,468 when it became operational in 1946.
Turing’s cryptographical genius was essential to the successes of Bletchley Park, but for many years after the war the site’s work remained a secret. In 1952 he was prosecuted for then-illegal homosexual acts and ‘treated’ with female hormones, before committing suicide in 1954. It wasn’t until the 1970s that Bletchley’s work, and Turing’s importance to it, became widely known. Gordon Brown’s official governmental apology for the way Turing was treated after the war didn’t come until 2009.
