In November 1937, George Stibitz, then working at Bell Labs, completed a relay-based calculator he later dubbed the "Model K", which calculated using binary addition. Replicas of the "Model K" now reside in the Computer History Museum, the Smithsonian Institution, the William Howard Doane Library at Denison University and the American Computer Museum in Bozeman, Montana, where the George R. Stibitz Computer and Communications Pioneer Awards are granted. Bell Labs subsequently authorized a full research program in late 1938 with Stibitz at the helm. Their Complex Number Computer, completed in November 1939 and put into operation in 1940, was able to do calculations on complex numbers. In a demonstration to the American Mathematical Society conference at Dartmouth Collegein September 1940, Stibitz used a modified teletype to send commands to the Complex Number Computer in New York over telegraph lines. It was the first computing machine ever used remotely.
Wartime activities and subsequent Bell Labs computers
After the United States entered World War II in December 1941, Bell Labs became active in developing fire-control devices for the U.S. military. The Labs' most famous invention was the M-9 Gun Director, an ingenious analog device that directed anti-aircraft fire with uncanny accuracy. Stibitz moved to the National Defense Research Committee, an advisory body for the government, but he kept close ties with Bell Labs. For the next several years, with his guidance, the Labs developed relay computers of ever-increasing sophistication. The first of them was used to test the M-9 Gun Director. Later models had more sophisticated capabilities. They had specialized names, but later on, Bell Labs renamed them "Model II", "Model III", etc., and the Complex Number Computer was renamed the "Model I". All used telephone relays for logic, and paper tape for sequencing and control. The "Model V", was completed in 1946 and was a fully programmable, general-purpose computer, although its relay technology made it slower than the all-electronic computers then under development. After the war, in 1945, Stibitz didn't returns to Bell Labs, but instead went into private consulting work.
Origin of the term "digital"
In April 1942, Stibitz attended a meeting of a division of the Office of Scientific Research and Development, charged with evaluating various proposals for fire-control devices to be used against Axis forces during World War II. Stibitz noted that the proposals fell into two broad categories: "analog" and "pulse". In a memo written after the meeting, he suggested that the term "digital" be used in place of "pulse", as he felt the latter term was insufficiently descriptive of the nature of the processes involved. The word "digit" at the time had two common meanings: the ten fingers of one's hands, and the numbers 0 through 9. The adjective "digital" was also in use, although it was not as common. For example, among physicians, a "digital" examination referred to the use of a doctor's finger to palpate part of the body. Stibitz's memorandum was the first known use of the term "digital" to refer to calculating machinery.
Stibitz held 38 patents, in addition to those he earned at Bell Labs. He became a member of the faculty at Dartmouth College in 1964 to build bridges between the fields of computing and medicine, and retired from research in 1983.
Computer art
In his later years, Stibitz "turned to non-verbal uses of the computer". Specifically, he used a Commodore-Amiga to create computer art. In a 1990 letter, written to the department chair of the Mathematics and Computer Science department of Denison University he said:
I have turned to non-verbal uses of the computer, and have made a display of computer "art". The quotes are obligatory, for the result of my efforts is not to create important art but to show that this activity is fun, much as the creation of computers was fifty years ago.
The Mathematics and Computer Science department at Denison University has enlarged and displayed some of his artwork.
