68 years ago, Alan Turing left Manchester for the summer. As part of his holiday he paid a visit to the Science Museum in South Kensington. For the 1951 Festival of Britain, they had agreed to display a new wonder: the Ferranti Mark I, the world’s first commercially available electronic computer. But, like most computer installations ever since, it couldn’t be made to work in time. So Ferranti created a last-minute replacement, the probably more crowd-pleasing wonder of the Nimrod.
Nimrod was the first computer game with an electronic display, and played a passable version of the matchstick game Nim. When Turing visited, he supposedly managed to both beat Nimrod at its own game, and then to break it, all the while keeping an eye on the attractiveness of the display attendants (he approved).
It’s no surprise that Turing could hack the Nimrod. His job in Manchester was as the resident, indeed the first, software specialist at the University, and, I discovered in research for my recent book, as a consultant for Nimrod’s maker, the electrical company Ferranti.
Nimrod and (eventually) the Mark I, were constructed up the Oldham Road in Moston, so I felt justified in including the Nimrod story in the book, Alan Turing’s Manchester. And it was at the Science and Industry Museum in Manchester, in a windowless basement, that I found a hitherto unknown account confirming the making of Nimrod as a Mark I replacement.
That document was part of the vast Ferranti archive that is one of the museum’s lesser known treasures. The archive also holds the photographic prints that mark the start of computer marketing. Where today David Bowie or FKA Twigs hunch over their Macbooks in black and white for Apple’s ‘Behind the Mac’ ads, in 1951 it was Alan Turing, in his role as programming expert, who leaned over the Mark I console to sell the machine of immense, if never quite specified, promise.
The Ferranti Mark I was based on a University prototype for which Turing wrote the world’s first, and by common consent worst, programming manual: when Ferranti commercialised the design they had to rewrite the manual more or less from scratch, and so the visitor to the archive can also find the resulting Ferranti manuals, acknowledging the support of ‘Dr A. M. Turing’.
The Science Museum Group’s collection connects with Turing in other ways, too. The various pieces of Douglas Hartree’s differential analyser, an analogue computing device heavily used during the war, attest to the expertise accumulating in Manchester in numerical techniques, that would be crucial in making it one of the two post-war British sites with a computer and attracting Turing to the city.
And from those brilliantly ingenious first few years of Manchester electronic computing, led by FC Williams and Tom Kilburn, there’s a surviving CRT tube of the technology that delivered the first practical computer memory, there are a few valves from the Baby that tested it, and an entire logic door from the Ferranti Mark I that commercialised it. But Turing had little direct input in that hardware inventiveness, and by the time the marketing shots had been taken, he was marginalised in the University and disappeared from the Ferranti archive too.