The ENIAC, finished in 1945 at the University of Pennsylvania, was the fastest electronic computer in the world: it did five thousand additions a second with almost eighteen thousand valves. But to change calculation one had to rewire cables and switches on a panel, a job of days done by a team of programmers. Two programmers operating the ENIAC’s control panel, at the Moore School of the University of Pennsylvania, around 1946.United States Army · Wikimedia Commons · public domain The ENIAC’s engineers, J. Presper Eckert and John Mauchly, were already planning the next machine, the EDVAC, in which the program would be kept in memory. Von Neumann began attending the meetings and, in June 1945, wrote a text that organised the group’s ideas in an abstract, almost biological language, speaking of “organs” and “neurons”.