Born to prosperous Jewish parents in Budapest in 1903, Von Neumann was a child prodigy who could divide eight-digit numbers in his head by age six, learned calculus by age eight and amused his parents' friends by glancing at a phone book and reciting whole pages verbatim. Mathematics quickly became the focus of his studies, culminating in a Ph.D. from the University of Budapest at the age of 23.

After immigrating to the U.S. in 1933, Von Neumann was hired, along with Albert Einstein, by the newly formed Institute for Advanced Study in Princeton, N.J., a nonprofit research institute set up by the Bamberger family with profits from their department stores. The I.A.S. proved to be the perfect intellectual playground for Von Neumann's boundless genius. He threw himself with enthusiasm into one intractable problem after another, ranging from the abstract mathematics of quantum mechanics to the practical problems of weather prediction, hydrology and the patterns of artillery fire.

Was there a mathematical structure behind parlor games like chess and poker? Von Neumann investigated and in the process invented game theory--a branch of mathematics that has brought new insights to fields as diverse as economics and evolutionary theory. The 1997 Nobel Prize in Economics was awarded to game theorists, the seventh Nobel Prize that grew out of Von Neumann's ideas.

With the onset of World War II, Von Neumann was recruited for the Manhattan Project and played a role in building both the A-bomb and the H-bomb. His main contribution was supervising the vast and complex mathematical calculations--done first by hand and later by primitive electronic computers--required to design the bombs.

After the war, he returned to the I.A.S. and became obsessed with computing. Von Neumann's vision for the machines went beyond the rote arithmetic tasks for which they were originally designed. In his idealized computer, the same memory units that held data items, such as numbers or text, also held the step-by-step instructions that would allow the machine to be programmed to perform any task. Von Neumann persuaded the I.A.S.'s somewhat skeptical board of trustees to allocate $100,000--quite a sum in 1945--to build the MANIAC, the first in a series of early Von Neumann machines that included the JOHNNIAC (at Argonne National Laboratory) and the IBM 701, one of the progenitors of IBM's enormously profitable mainframe lines.

I recently visited the I.A.S. archives and paged through Von Neumann's handwritten lab notebooks describing the construction and testing of his primitive computer systems. Interspersed with technical data are comments such as, "5 a.m.: I've been at this all night, and I still can't find the problem. I'm disgusted and I'm going to bed!"--a sentiment any computer programmer will recognize. Von Neumann didn't just design the stored-program computer; he was the first hacker.

As rivalry with the Soviet Union heated up, Von Neumann became a strategic adviser on defense policy. He was appointed by President Dwight D. Eisenhower to the Atomic Energy Commission, which oversaw the postwar buildup of the U.S. nuclear arsenal. Von Neumann's game theory became a tool to analyze the unthinkable--global nuclear war--and led to the doctrine of "mutually assured destruction," which would shape U.S. strategy for the next two decades. Von Neumann also became an icon of the cold war. Disabled with pancreatic cancer, he stoically continued to attend AEC meetings until his death in 1957. The wheelchair-bound scientist with the Hungarian accent who mathematically analyzed doomsday is said to have been a model for Stanley Kubrick's Dr. Strangelove.

Nathan Myhrvold, chief technology officer for Microsoft, collects old supercomputers