UNIVAC

UNIVAC, (UNIVersal Automatic Computer), the first electronic computer designed and sold to solve commercial problems. The UNIVAC contained about 5000 vacuum tubes, occupied 943 cubic feet, and weighed 8 tons. From 1951 to 1957 a variety of governmental and commercial customers bought a total of 48 UNIVAC computers.

The UNIVAC was a successor to the first general-purpose electronic computer, the ENIAC (Electronic Numerical Integrator And Calculator). The ENIAC was built for the United States armed services by American physicist John Presper Eckert, Jr., and American electrical engineer John Mauchly between 1943 and 1946. It was the first large-scale, general-purpose electronic computer. In 1947 and 1948 Eckert and Mauchly built an improved machine called the EDVAC (Electronic Discrete Variable Automatic Computer), which incorporated some important design innovations by Hungarian American mathematician John von Neumann. In December 1948 Eckert and Mauchly left the University of Pennsylvania, where they had worked, and formally organized the Eckert-Mauchly Computer Corporation. In August 1949 they delivered a computer for (onboard) missile control to the Northrup Corporation, which they called BINAC (BINary Automatic Computer). BINAC was to be the prototype for the commercial UNIVAC system.

In March 1951 Eckert and Mauchly delivered the first UNIVAC to the U.S. Census Bureau. The UNIVAC gained national attention in 1952 when General Dwight D. Eisenhower was running against Adlai E. Stevenson for the presidency of the United States. A UNIVAC was used to predict the results of the election on national television. Using an early ballot count of only a few percent of the votes, UNIVAC predicted a landslide win for Eisenhower. The television networks delayed announcement of the predicted margin until a greater percentage of election returns could be counted. When a large enough percentage of the votes was finally counted, it was found that UNIVAC had been correct in its predictions. This successful demonstration contributed greatly to the popularity of the UNIVAC as well as to the public’s opinion of computers.

The UNIVAC contained many improvements over the earlier ENIAC. The number of vacuum tubes in the UNIVAC was reduced to about 5000 from ENIAC’s 19,000. UNIVAC’s 943 cubic feet of cabinets took up less floor space than ENIAC, but it still would have filled a single-car garage. The UNIVAC weighed 8 tons instead of the ENIAC’s 30 tons, and it consumed about 100 kilowatts of power instead of the 175 kilowatts of power that the ENIAC used. Despite the major improvements of the UNIVAC over the ENIAC, it was still extremely inefficient by today’s standards.

UNIVAC, like its predecessor ENIAC, used decimal arithmetic with vacuum tube logic, counting serially up and down to ten with each string of vacuum tubes in the arithmetic storage registers. UNIVAC’s memory, holding both the data and program, was built from mercury delay-line tubes. These large horizontal cylinders contained liquid mercury that circulated acoustic vibrations representing stored data and instruction values. Each memory line could accommodate 1024 words, with each word holding one 12-digit data value or two 6-digit instruction values. External data could be read from and written to magnetic tape, as well as from punch cards and to printers. The UNIVAC could perform up to 1905 operations per second. Primarily designed for business applications, the UNIVAC worked well with both fixed-precision decimal digits and text character data. Early UNIVAC customers included government agencies, the A. C. Nielsen Company, the Prudential Insurance Company, and the General Electric Appliance Division. UNIVAC computers were used for many different purposes, including accounting, data processing, and record keeping.

Before Eckert and Mauchly began production of the UNIVAC system, they realized that they would need significant financial support to start the production of multiple systems and to support these systems. This was particularly true since most customers wanted to lease the computers rather than buy them outright, due to their high cost—about $1 million. Because of financial difficulties, Remington Rand bought the Eckert-Mauchly Computer Corporation in 1950 and changed its name to the Univac Division of Remington Rand. In the early 1950s another company, Electronic Research Associates (ERA) of St. Paul, Minnesota, was building computers for scientific applications requiring higher precision arithmetic than the UNIVAC performed. In 1952 Remington Rand bought ERA and the two groups worked together to produce later models of the UNIVAC computer series.