1942-1943

1942
The Atanasoff-Berry Computer
The Atanasoff-Berry Computer is completed. Built at Iowa State College (now University), the Atanasoff-Berry Computer (ABC) was designed and built by Professor John Vincent Atanasoff and graduate student Cliff Berry between 1939 and 1942. While the ABC was never fully-functional, it won a patent dispute relating to the invention of the computer when Atanasoff proved that ENIAC co-designer John Mauchly had come to see the ABC shortly after it was completed
1943
Whirlwind installation at MIT

Project Whirlwind begins. During World War II, the U.S. Navy approached the Massachusetts Institute of Technology (MIT) about building a flight simulator to train bomber crews. The team first built a large analog computer, but found it inaccurate and inflexible. After designers saw a demonstration of the ENIAC computer, they decided on building a digital computer. By the time the Whirlwind was completed in 1951, the Navy had lost interest in the project, though the U.S. Air Force would eventually support the project which would influence the design of the SAGE program.

George Stibitz circa 1940
The Relay Interpolator is completed. The U.S. Army asked Bell Labs to design a machine to assist in testing its M-9 Gun Director. Bell Labs mathematician George Stibitz recommended using a relay-based calculator for the project. The result was the Relay Interpolator, later called the Bell Labs Model II. The Relay Interpolator used 440 relays and since it was programmable by paper tape, it was used for other applications following the war.