Alan M. Turing: If you build it, they will compute

 Alan M. Turing met John von Neumann in 1935, when Von Neumann was a visiting professor at Cambridge, England, and from 1936 through 1938, when Turing obtained a PhD from Princeton University.  Turing's paper on undecidability and the concept of Turing machines (particularly a universal Turing machine) influenced Von Neumann in his work on stored-program computers.  Before that, calculating machines were programmed with wiring panels or punched paper tape, which did not allow for branches in the sequence of instructions or modification of the instructions.  Turing took Von Neumann's preliminary design and completed it, which was used at Britain's National Physics Laboratory to build the Pilot ACE (Automatic Computing Engine),one of the first electronic stored-program computers.  In 1948, Turing went to The University of Manchester where he worked on the design of the Manchester Mark 1.

A Pilot ACE Simulator is available at http://www.pilotaceonline.com/index.html.