The Remington Rand 409, a punched card calculator which was programmed with a plugboard, was designed in 1949. It was sold in two models: the UNIVAC 60 (1952) and the UNIVAC 120 (1953). The model number referred to the number of decimal digits it could read from each punched card. The machine was designed in "The Barn", at 33 Highland Ave. in Rowayton, Connecticut, a building that currently houses the Rowayton Public Library and Community Center. These machines were discontinued when the UNIVAC 1004 was introduced in 1962. About 1000 total had been produced by 1961.

Architecture

Numbers were fixed-point and of variable length (one to ten digits). Arithmetic was done in floating point, but all results were converted to fixed point when stored in memory. Digits are represented in bi-quinary coded decimal. Each digit of memory storage contained five tubes. Four of these represented the digits 1, 3, 5, and 7, while the fifth tube represented 9 if activated alone but added 1 to the value if activated together with another tube.

Hardware