National Academy of Engineering Memorial Tributes: National Academy of Engineering, Volume 10
Membership Directory
PublisherNational Academies Press
Memorial Tributes: National Academy of Engineering, Volume 10

Search this Publication

  • Previous
  •    Table of Contents
  • Next
             J.PRESPER ECKERT                                          71
                            J.PRESPER ECKERT
                                  BY LEO L.BERANEK
                JOHN PRESPER ECKERT, or as he preferred, J. “Pres” Eckert, was born
            April 9, 1919, in Philadelphia, Pennsylvania. He received the bachelor of science
            degree from the University of Pennsylvania in 1941. His 1943 master of science
            degree in electrical engineering was from the University’s Moore School of
            Electrical Engineering. Pres and his wife, Judith, had four children and made
            their home in Gladwyne, Pennsylvania. He was known as a serious worker who
            wanted things done right. His family and his students at the university attest to his
            readiness to be helpful and his devotion to vigorous and healthy living. He died
            June 3, 1995, in Bryn Mawr at the age of seventy-six.
                A brilliant student, Pres was named a part-time laboratory instructor in his
            second graduate year at the Moore School. His charge was to teach the principles
            of engineering to students from other fields with the goal of making them able to
            work effectively in the World War II effort. His class comprised more than thirty
            students, sixteen of whom had their Ph.D.s. It was through that course that he
            met John W.Mauchly, whose doctorate was in physics.
                In 1942 and 1943, Eckert became involved in improving a version of
            Vannevar Bush’s differential analyzer, invented at the Massachusetts Institute of
            Technology. After considerable success, Mauchly and he discussed how much
            further its performance could be improved by more precisely machined parts and
             J.PRESPER ECKERT                                          72
             carefully controlled, air-conditioned space. They decided that this path was not
             fruitful. Together, they invented a digital differential analyzer, which was an
             electronic version of the mechanical Bush machine. Because it inefficiently
             counted pulses sequentially, they decided to build a machine that would use some
             sort of coded binary decimal system. This work proceeded slowly at first, because
             Eckert was doing graduate work and Mauchly was teaching. Mauchly then had
             the idea that an electrical device could be built that would have places to hold
             numbers, add numbers, and integrate equations. At that time, the only fast input
             and output equipment used punch cards, so the system had to be a combination of
             binary and coded decimal. But those ideas were sketchy.
                Eckert contributed the engineering designs that made Mauchly’s proposal
             practical. In early 1943, Mauchly wrote up their joint plans for this new type of
             computer. The Moore School knew that the army had critical needs for computing
             and that no existing machine was satisfactory. Using electromechanical
             calculators, the army was actively preparing ballistic tables to be used by the
             artillery crews in battle to determine the trajectories of missiles. The results were
             not very accurate. Thus, it was decided to seek funding for this proposed project
             from the U.S. Army Ballistics Research Laboratory in Aberdeen, Maryland. The
             presentation of the Eckert-Mauchly proposal was made by the department’s
            administrator, John Brainard. Sometime before this date, Eckert had begun work
            on a mercury tank for measuring timing signals in connection with radar, arising
            from a request by MIT’s Radiation Laboratory. Although this work had to be
            abandoned when the new project started, it would be important later.
                The Eckert-Mauchly computer proposal was approved on April 9, 1943, and
            $150,000 was allocated for a machine with ten accumulators, a means for taking
            square roots using the Newton-Rapson method, and one function table with 104
            entries, and so on. As time went on, the number of accumulators was doubled, a
            square root divider was substituted, and three function tables were mandated. The
            machine grew from eighteen panels to something like forty panels, and the
            appropriation was
             J.PRESPER ECKERT                                          73
             increased to about $400,000. Thus, the basis was in place for the development of
             the Electronic Numerical Integrator and Computer (ENIAC). Eckert was
             designated chief engineer on the project.
                The ENIAC project called for vacuum tubes (transistors were not yet
             invented) and 18,000 were eventually used. Initial efforts were spent in learning
             how to extend their lives by reducing plate voltages and filament currents. Other
             memory ideas, such as recording magnetically on disks, were contemplated, but
             military urgency dictated that there could be no distraction from using vacuum
             tubes. There was external criticism about the mathematical basis for the
             calculations, which turned out later not to be important. On the hardware side,
             many questioned the feasibility of making 18,000 vacuum tubes work without
             failure for any significant length of time. Although statisticians predicted a mean
             free-path error of a couple of minutes, the results were greater by a hundred times
             or more than such predictions, or a lifetime of about 2,500 hours for each tube.
                A staff of twelve professionals was involved in the development, and Eckert
             had to make the equipment decisions and the staff assignments, coordinate the
             activities, and finally develop means for testing the computer. Mauchly was more
             interested in programming, although he did some of the engineering, particularly
             in the final debugging of the completed machine. The computer was completed
             and ran its first real task in 1946. It measured about 2.5 meters in height and
             twenty-four meters in length. Programming was done by plug boards and
             switches. The computer, which was to operate until 1955, was more than 1,000
             times faster than its electromechanical contemporaries and could execute up to
             5,000 additions per second. An important feature was the subroutine scheme,
             which allowed the user to do an operation over and over until some criterion was
             met. This was handled through a special panel called a master programmer.
             Eckert explained, “The process of computing was carried on by ‘accumulators.’
            Accumulators differ from a mechanical adding machine both because they are
            electronic and because you can control their start and finish, simultaneously
            transmit a number to one place as positive and to another as negative, and so
             J.PRESPER ECKERT                                          74
                Eckert next turned his attention to building a better machine. One vital
            improvement was the use of a mercury tank as the central memory, which was
            later supplanted by core memory. Incorporating it, a machine called the EDVAC
            was contemplated. Eckert and Mauchly left the Moore School in October 1946.
            Work on the EDVAC was continued by others at the Moore School.
                Eckert and Mauchly founded the Electronic Control Company in October
            1946. Their first order was received from Northrop Aircraft Company. That
            machine, called the Binary Automatic Computer (BINAC), was principally
            different in that it stored data on a magnetic tape rather than on punched cards.
                The Electronic Control Company was renamed the Eckert-Mauchly
            Computer Corporation in 1949. They received an order from the National Bureau
            of Standards to build the Universal Automatic Computer (UNIVAC). Memory
            was the big problem—it finally evolved that a hierarchy of memories was
            necessary, as in today’s computers. This was the first breakthrough. The second
            was the improvement of the subroutines, which led to internal programming. The
            UNIVAC, the first digital machine to be produced commercially in the United
            States, was delivered in 1951 to the United States Census Bureau. Eventually,
            forty-six UNIVACs were built. For the first time in computer history, a
            computing device was able to handle both numerical and alphabetical information
            with equal success. Mauchly, twelve years older than Eckert, left the company in
            1950 and started his own consulting firm. He died in 1980.
                In 1950 the Eckert-Mauchly Corporation was acquired by the Remington
            Rand Corporation and Eckert was appointed director of engineering of the
            Eckert-Mauchly Division. Successively, he was named vice-president and
            director of commercial engineering at Remington Rand (1955 to 1959), vice-
            president and executive assistant to the general manager of Remington-Rand
            (1959 to 1963), and vice-president and technical adviser to the president, Univac
            Division, Sperry Rand Corporation (1963 to 1982). When Sperry merged with the
            Burroughs Corporation to become Unisys in 1986, he stayed with the company
            and became a consultant. In 1989 Eckert retired from Unisys.
             J.PRESPER ECKERT                                          75
                In 1968 the Honeywell Corporation challenged the patents covering the
            invention of the ENIAC computer. The presiding judge ruled in favor of
            Honeywell’s claim that John Mauchly’s ideas for electronic devices were
            obtained from meetings with John Vincent Atanasoff during a visit to Iowa in
            1941. In an interview in 1981, Eckert stated that he and Mauchly had invented the
            computer “in the same sense that Edison invented the lightbulb.” He said, “there
            were people who thought of the idea and tried to build one, but it didn’t work
            very well.”
                In 1964 J.Presper Eckert received an honorary D.Sc. degree from the
            University of Pennsylvania. He was elected a member of the National Academy
            of Engineering in 1967. In January 1969 the National Medal of Science was
            awarded to Eckert by President Lyndon B.Johnson. In April 1969 he was awarded
            honorary membership in the Information Processing Society of Japan, and the
            “Eckert Award” was established in his honor for authors of best computer
            treatises. The Franklin Institute presented him with the Philadelphia Award in
    • Previous
    •    Table of Contents
    • Next