IN 1944, [HERMAN] GOLDSTINE and a small group of engineers at the University of Pennsylvania's Moore School of Engineering had been building a new type of calculating machine with government funding that used vacuum tubes rather than gears to run calculations. They called it the ENIAC, an acronym that summarized its functions as an electronic numerical integrator and computer. 
It was just what [John] von Neumann and Los Alamos had been looking for. The Hungarian-born mathematician embraced the machine and the concept of the machine and soon abstracted from its crude vacuum-tube technology a logical system for manipulating and processing information, mathematical or otherwise. Goldstine believes von Neumann's 101-page draft report, written that final winter quarter and spring of the war, was "the most important document ever written on computing and computers." The ENIAC as the Moore School group had designed it had to be prepared for each new problem by physically rearranging its circuit wires, plugging and unplugging what looked like old-fashioned telephone switchboards. In his draft report, von Neumann formulated for the first time the idea of a stored operating program—and defined in the process the basic organization of the digital computer: "The logical control of the device, that is, the proper sequencing of its operations, can be most efficiently carried out by a central control organ. If the device is to be... all purpose, then a distinction must be made between the specific instructions given for...a particular problem, and the general control organs which see to it that these instructions—no matter what they are—are carried out."
The first problem assigned to the first working electronic digital computer in the world was the hydrogen bomb.
Dark Sun: The Making of the Hydrogen Bomb
© 1995 by Richard Rhodes
Simon and Shuster, Inc.
Touchstone Edition (1996) pp. 250-251