Electrical engineer J. Presper Eckert (1919-1995)invented the first general-purpose electronic digital computer, the ENIAC, with John William Mauchly. Further collaboration between the two engineers led to the development of the first commercial digital electronic computer, UNIVAC. Their combined efforts ushered in the commercial computer revolution that continues to change the world in profound ways.

John Presper Eckert, Jr., was born on April 9, 1919, in Philadelphia, Pennsylvania, to John Presper Eckert and Ethel Hallowell Eckert. His father was a self-made millionaire businessman, whose business interests would strongly influence his son's future. Eckert was an only child, and spent much of his youth building radios and other mechanical and electronic gadgets. He wanted to attend the Massachusetts Institute of Technology (MIT), but his mother did not want him to move so far away. To keep his son close to home, his father claimed that he could not afford to pay MIT's steep tuition. Therefore, Eckert settled on the Moore Engineering School at the University of Pennsylvania. Upon discovering his father's lie during his freshman year, Eckert became very angry, which had a negative effect on his grades. But he persisted at Moore, earning his undergraduate degree in electrical engineering in 1941 and his master's degree in 1943. On October 28, 1944, Eckert married Hester Caldwell. The couple had two sons, John Presper III and Christopher, before Hester died in 1952. Eckert married Judith A. Rewalt on October 13, 1962 and had two more children, Laura and Gregory.

Eckert was widely regarded as a superb engineer while at the Moore School. However, he could be stubborn, and his work habits were considered odd. As Robert Slater wrote in Portraits in Silicon, "Eckert liked to work things out orally in the presence of someone; it didn't matter whether it was a technician or a night watchman. He was highly nervous and would rarely sit in a chair or stand still while thinking. Often he would crouch on top of a desk or pace back and forth."

Invented First General Purpose Electronic Computer

The first of the four computers that Eckert built with Mauchly was the ENIAC (Electronic Numerical Integrator and Computer). The ENIAC was comprised of over 10,000 capacitors, 70,000 resistors, and 500,000 soldered connections. Separate wire panels defined each of its programs, which meant that operators had to change its wiring manually by turning dials, changing switches, and moving cables every time they changed to a new program. Adding to its complexity were nearly 18,000 vacuum tubes, any one of which could burn out at any time and stopped a calculation. An expert on electric organs, Eckert thought about this problem carefully. He knew that organs contained many vacuum tubes that could be used over long periods of time without burning out, and found that if he ran the computer's tubes at a low rate of power, they too would last a long time. Eckert also instituted careful standards for the computer's circuits. He designed each one individually and insisted, for the sake of simplicity, that only his circuits be used in all areas of the computer. This enabled everyone who worked on the computer to understand exactly how it worked very quickly, which minimized confusion.

At 80 feet (24 m) long, eight feet (2.4 m) high, and three feet (1 m) deep, the ENIAC occupied a total of 1,800 square feet (167 sq. m) and weighed 30 tons. Although it was enormous, power hungry, and slow compared to the average personal computer of the 1990s, its calculating speed was 1,000 times faster than any mechanical calculator built up to that time. ENIAC could calculate a trajectory for an artillery shell in 30 seconds, while it took a person using a mechanical desk calculator 20 hours to perform the same calculation, with the possibility of error. The ENIAC was a general-purpose computer that could add, subtract, multiply, divide, compare quantities, and extract square roots. It did not become operational until after World War II. The ENIAC passed its first full operational test on December 10, 1945, and was dedicated on February 16, 1946. In August 1947, it was used to solve trajectory problems and compute ballistics tables at the U.S. Army's Aberdeen Proving Ground, and was later engaged in the development of the hydrogen bomb. In 1944, while working as a research associate at the Moore School, Eckert began work with Mauchly on the EDVAC (Electronic Discrete Variable Automatic Computer), greatly advancing the functions of its predecessor. Completed in 1952, EDVAC had an internal memory for storing programs, used only 3,600 vacuum tubes, and took up a mere 490 square feet (45 sq. m).

Developed First Commercial Computer

Shortly before the end of World War II, Eckert and Mauchly, with grudging permission from the Moore School of Engineering, began the long process of patenting the ENIAC. However, subsequent administrators at the Moore School did not like the idea of their employees applying for patents on equipment developed for U.S. government projects. In early 1946, one administrator decided that the Moore School would retain future patents on all projects developed by employees of the school. When asked to sign a form consenting to this, Eckert and Mauchly refused, and resigned in March 1946.

Though IBM had offered Eckert a job and his own lab for developing computers, Mauchly talked him into jointly starting the Electronic Control Company. Their first work, in 1946 and 1947, was with the National Bureau of Standards and the Census Bureau. They developed the specifications for a computer eventually known as the UNIVAC (Universal Automatic Computer)--the Electronic Control Co. took this as its name in 1948. Like most start-up companies developing complex hardware, Eckert and Mauchly ran into their share of financial problems, consistently underestimating the development costs for their computers. To raise money, they signed a contract in the fall of 1947 with the Northrop Aircraft Company to create a small computer for navigating airplanes--the BINAC (Binary Automatic Computer). The BINAC (completed in August 1949) and the UNIVAC were the first computers to employ magnetic tape drives for data storage. Smaller in size and comprised of fewer parts than the ENIAC, both machines had internal memories for storing programs and could be accessed by typewriter keyboards.

Eckert and Mauchly had been kept from bankruptcy by the support of Henry Straus, an executive for the American Totalisator Company, which manufactured the odds-making machines used at race tracks. When Straus was killed in a plane crash in October 1949, Eckert and Mauchly knew they had to sell UNIVAC. The Remington Rand Corporation acquired their company on February 1, 1950. Eckert remained in research to develop the hardware for UNIVAC, while Mauchly devoted his time to developing software applications. The first UNIVAC, delivered to the Census Bureau in March 1951, proved its value in the 1952 presidential election between Dwight Eisenhower and Adlai Stevenson, when it accurately predicted results less than an hour after the polls closed. Eckert and Mauchly's patent on the ENIAC was challenged during an infringement suit between Sperry-Rand (formerly Remington), who now owned the rights to the computer, and Honeywell. On October 19, 1973, the court invalidated the ENIAC patent and asserted that Iowa State University professor John Vincent Atanasoff was the true inventor of the digital electronic computer.

Eckert received his honorary doctorate from the University of Pennsylvania in 1964. He also received 87 patents and numerous awards for his innovations, including the Howard N. Potts and John Scott Medals (both of which he shared with Mauchly). President Lyndon B. Johnson presented him with the National Medal of Science in 1969. Eckert was elected to the National Academy of Engineering in 1967. He remained with the Remington Rand Corporation through a number of mergers, retiring in 1989. He later served as a consultant to UNISYS and to the Eckert Scientific International Corporation, based in Tokyo, Japan. At the time of his death, Eckert was a resident of Gladwyn, Pennsylvania. He died on June 3, 1995 in Bryn Mawr, Pennsylvania.

Further Reading

• A History of Computing in the Twentieth Century. edited by N. Metropolis, et. al., Academic Press, 1980.
• Shurkin, Joel, Engines of the Mind. Pocket Books, 1984.
• Slater, Robert. Portraits in Silicon. MIT Press, 1987.
• Stern, Nancy. From ENIAC to UNIVAC: An Appraisal of the Eckert-Mauchly Computers. Digital Press, 1981.
• New York Times, June 7, 1995.