# George Stibitz

###### George Stibitz (1904-1995)

Stibitz developed the principles behind relay-based computers as a researcher at Bell Labs. During World War II, he worked on anti-aircraft guns. Following post-war consulting work, Stibitz continued his research at Dartmouth College.

###### George Stibitz

While working at Bell Labs, mathematician George Stibitz experimented with relays at home. He developed a circuit to add binary numbers, which led to a relay-based computer.

This Complex Number Calculator, operational in 1940, was demonstrated remotely at a conference using a Teletype – the first computer accessed over a phone line.

###### "Model K" Adder (replica)

George Stibitz made the original version of this in 1936 on his kitchen table, hence the name “Model K.” Using scrapped relays from Bell Labs and strips of metal from a tin can, it can add two binary digits. Stibitz himself built this replica.

View Artifact Detail###### Teletype operator using the Complex Number Calculator

A typist entered problems suggested by attendees at the American Mathematical Society meeting at Dartmouth, New Hampshire in September 1940, and remotely operated the Complex Number Calculator in New York.

View Artifact Detail###### Bell Labs Model I Relay Calculator (Complex Number Calculator)

The Complex Number Calculator, made from 450 telephone relays, could multiply and divide 8-digit numbers. The last follow-on machine, the Model VI, was completed in 1950 and ended up at the Bihar Institute of Technology in India in the 1960s.

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