ENIAC Settles Down to Work

Abstract

ENIAC’s new configuration was stabilized with further tweaks over the summer of 1948. Over the next seven years it ran more than a hundred different applications, and was gradually transformed from an unreliable white elephant that took a month of struggle to provide a single day of usable computing time into a computing workhorse able to run several computations each day. Changes to its hardware continued, including attempts to upgrade its memory with mercury delay lines (unsuccessful) and an early core memory unit (successful). Discussion focuses particularly in its use in 1950 to run the first numerical weather simulations. This pushed ENIAC to its limits, illuminating its capabilities and limitations in comparison to its successor. The authors also document the changing relationship between ENIAC and two newer computers (EDVAC and ORDVAC) that became operational at BRL in 1952 and eventually took over its workload. It was decommissioned in 1955.