Engineer at operators console of transistorized Litton 20 Digital Differential Analyzer
Photo Credit: University of Southern California/California Historical Society

The operator's console of the Litton 20 digital differential analyzer(DDA). The electronics of the machine are contained in the cabinet located behind and to the right of the desk that has the operator's console on it.

The Litton 20, introduced in 1956, was produced by Litton Industries. The logic circuitry is made from transistors, making it one of the earlier transistorized electronic computing machines. The Litton 20 was not a general-purpose computer or calculator - its logic circuitry was permanently "wired" for the solution of of linear and non-linear differential equations. It consisted of 20 digital integrators that were capable of carrying out 60 integration cycles per second, with parameters stored on a magnetic drum memory. The machine had a base price of approximately $10,000.