History of Computers - Complex Number Calculator
Created By: Kurt Louie
The complex number calculator was a machine capable of adding, subtracting, multiplying, and dividing complex numbers. In 1940, the complex number calculator was used for the first demonstration of remote computing.
Overview
Creation
In November of 1937, a research mathematician at Bell Labs, George Stibitz, brought two telephone relays, a few couple of flashlight bulbs, a wire and a dry cell to his house and assembled a simple logical device that could indicate a "1" or a "0". This device was dubbed the "K-Model" by his wife Dorothea and is now known as a relay. While his colleagues reasoned that a practical relay computer would need hundreds of relays, making it more bulky and expensive than those already in use, Stibitz realized that the calculator could perform a sequence of calculations. Specifically, it could perform the operations required to perform multiplication and division of complex numbers. Researchers elsewhere at the Bell Labs were in need of a machine that could perform this.
K-Model
Although it was rejected at first, Bell executives quickly changed their mind because Bell needed to find a way to solve its increasingly complex mathematical problems. Stibitz completed the designs in February, 1938, and the construction of the machine began in April, 1939 by Samuel Williams, another worker at Bell. In October of 1939, the final product was ready, and it was in operation from 1940 to 1949. It used 400-450 binary relays, 6-8 panes, and ten multiposition, multipole relays that could temporarily store numbers.
Around 1940, at a meeting of the AMS (American Mathematical Society) at Dartmouth College, he connected the CNC (which was in New York) with a telegraph system, and used the machine to remotely calculate problems. This technology is still in common use today, though not in the exact same form.
Significance
The CNC is significant because it was one of the first machines to make use of relays. The machine was used by Bell Labs for 9 years, and was used for the first public demonstration of remote computing
References
http://www.computer.org/web/awards/goode-george-stibitz
http://history-computer.com/People/StibitzBio.html
http://history-computer.com/ModernComputer/Relays/Stibitz.html
