The story of the computer is fascinating; it underpins everything from Facebook, travel, supermarkets and Twitter to finance, healthcare and the supply of electricity to our homes so that we can read books on well-charged iPads.
Controversy surrounds the earliest days of the technology. Both the UK and the US started developing computers during the Second World War, but the secrecy around such work meant many ideas were not revealed until decades later, by which time "The Story" had already taken shape in the collective consciousness.
George Dyson, a historian of technology who is the son of mathematician Verena Huber-Dyson and theoretical physicist Freeman Dyson, has studied the archives intensively. The story begins in a shed near the Institute for Advanced Study in Princeton, where his parents worked and where he played as a child. For him, the shed sparks memories of the earliest computers. It's best to imagine going into this shed, settling into a comfortable chair and asking George to tell us his story, for it is fascinating - and rambling.
John von Neumann is the main character in this book, an extremely clever mathematician who drove the development of the first computer: he arrived at the institute a year after Einstein. That's the simple picture, and today's computers - even your iPad - have von Neumann architecture in his memory.
The bigger picture starts with William Penn drafting a constitution for an American colony in 1676; no, it starts in Hitler's Kristallnacht just before the Second World War; no, it starts with the rush to develop a nuclear weapon and the need to solve lots of hard technical problems with shock waves, a special interest of von Neumann's. In fact, the secret use of the early computer was disguised in weather calculations, yet von Neumann was clear that controlling the weather would be more powerful than controlling the Bomb.
The characters take sides on the moral grounds for working on the Bomb; to some it is obscene to work out how to kill civilians, to others it is a mathematical problem to be solved.
There is rich history in the words of the players themselves. We get insights into amazing technical achievements, although they sometimes drift off seamlessly into Dyson's poetic imagination. But the flow of the book represents the tortuous flow of human achievement - von Neumann himself believed that mathematics grows best in close contact with human striving. This isn't just the story of great computer design: it involves divorce, fast cars, secrets, suicides and hints of wartime paranoia, as well as spending too much money on sugar for the tea. Each is a diversion, but relax in your comfortable chair: these are real people, and the war was a time of confusion and urgency - and a sense of being able to get amazing things done.
There are premonitions of trials ahead. For example, Stan Ulam, a close colleague of von Neumann, testified in 1971 over ENIAC. What trial, and what was it about? To find out what ENIAC is, the index takes us to page 64, where we are told that its existence wasn't made known until 1946; on page 70, we are told the project was launched in 1943...and on page 321, ah, there seems to be a dispute, wrapped up in security issues, forcing the inventors to sell their patents. There is no map to any timeline.
This isn't a history of computers, then: this is a reminiscence of the interleaved human story, with a greater emphasis on the scenery along the way than the destination - our computerised world. If you like the context of human poignancy, from starting wars with Jewish oppression to winning them with overwhelming carnage, this is reality; if you want to understand the technology, be patient - the humanity is the motivation.
Von Neumann, dying of cancer and unable to work without notes, envisages what we'd now think of as an iPad projecting on to the ceiling so one could lie back and read and write. "Pure bred consciousness without physical interference" - much like Turing's Cathedral itself.
Turing's Cathedral: The Origins of the Digital Universe
By George Dyson Allen Lane
432pp, £25.00 and £14.99
ISBN 9780713997507 and 9780718194505
Published 1 March 2012