Los Alamos Bets on ENIAC: Nuclear Monte Carlo Simulations, 1947-1948

In April 1948 a team including John and Klara von Neumann and Nick Metropolis ran the first of a series of calculations on ENIAC. These were not only the first computerized Monte Carlo simulations, but also the first code written in the modern paradigm, usually associated with the "stored program concept," ever to be executed. This article--the third in a three-part series published in Annals--reconstructs the planning, design, code, and operation of these programs from extensive archival records.