The thirty-ton calculator
Before smartphones and laptops, there was ENIAC—the Electronic Numerical Integrator and Computer. Unveiled to the public on February 14, 1946, it was the first programmable, electronic, general-purpose digital computer. Developed in secret during World War II at the University of Pennsylvania's Moore School of Electrical Engineering, its primary mission was to calculate artillery firing tables for the U.S. Army. A task that took a human computer 12 hours could be done by ENIAC in 30 seconds.
The machine's scale was immense. It weighed 30 tons, occupied a 30-by-50-foot room, and consisted of 40 nine-foot-high cabinets arranged in a U-shape. Its electronics included approximately 18,000 vacuum tubes, 70,000 resistors, 10,000 capacitors, and 6,000 manual switches. Programming the ENIAC did not involve writing code in a language but physically rewiring cables and setting thousands of switches, a process that could take the team of six female programmers days to complete for each new problem. After the war, ENIAC was moved to the Aberdeen Proving Ground in Maryland, where it ran until October 2, 1955. The Smithsonian has several of the original 40 panels.