John von Neumann is probably best well known by laymen for his contributions to computer science. His interest in computers most strongly began while he was working for the military in WWII. He was attempting to solve problems of hydrodynamics related to his weapons research (Gillispie). The complexity of these problems, and later the new problems presented by nuclear energy, led von Neumann to the field of computing. In 1944, von Neumann began working on ENIAC, or Electronic Numerical Integrator and Computer, which was being developed at the University of Pennsylvania. It was von Neumann who, with his crucial contributions, that made ENIAC not just a calculator, but a primitive stored program computer ( Kov รก cs ). The most important concept of which is storing program instructions in memory just as is done with data. The first test runs of the computer were used to run computations for the hydrogen bomb (Goldstine). In 1946 ENIAC was handed over to the US governme...