(Created by Sally Zabransky, History 135, April 2001)
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How did the mainframe computer evolve from its military beginnings in the 1940s to become a driving force behind the modernization of American business in the 1950s and 1960s?

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During World War II, one of the most significant assignments given to the United States Ordnance Department was the computation of data derived from the research and development efforts of the Army Ground Forces, the Army Air Force and, to a lesser degree, the Navy.  The need to develop new weapons at speeds and accuracy never thought of before meant that the use of the desk calculator to calculate ballistics was sorely in need of upgrading.  It was in this interest of national defense, that the development of electronic computing systems could not wait for the normal laws of economics to bring about the creation of such systems through commercial demand.  The development of the Electronic Numerical Integrator And Computer, ENIAC, was a collaborative effort between members of the armed forces and a few civilians highly trained and skilled in conventional methods of computation.

The ENIAC was proposed in 1942 and completed in 1946.  During this time ENIAC was used to solve problems in such fields as atomic energy and ballistic trajectories.

With the end of the War, the world's first electronic automatic computer opened up greater possibilities for advances in science and engineering and also started a new multi-billion dollar industry.  The ENIAC was the prototype from which most other modern computers evolved. Because of the joint efforts of the military and civilian workforce, the private sector quickly gained advantages in the development of electronic computing systems for peacetime purposes.

Following the War, the Remington Rand Corporation acquired the Eckert/Mauchley Company.  (John Mauchly and Presper Eckert headed the Moore School of Electrical Engineering at the University of Pennsylvania which completed the ENIAC project.)  This acquisition provided the company with the resources that developed the first UNIVAC computer.  By 1951 the Remington Rand Corporation unveiled its first non-military computer prototype to potential customers and in 1953 it delivered the Model 409 to the Internal Revenue Service in Baltimore, Maryland.  The Model 409 was one of the first computers used in the United States for non-military purposes.

Similarly, International Business Machines (IBM) was also at the disposal of the United States government during the war years and, it was during this time that IBM first began its development of electronic computing systems.  IBM also benefited greatly from its relationship with the government in its development of electronic computing systems for the private sector following the war years.  In 1952 the company introduced the IBM 701, its first large computer based on the vacuum tube.  The 701 could execute 17,000 instructions per second and was used primarily for government and research work.  The vacuum tube, however, made it an easy transition for the electronic computing system to make its appearance in areas such as billing, payroll and inventory control.

One would be hard pressed to name an industry that was not been influenced in one way or another by the computer.  Computers have been solving complex problems in fields ranging from farming, to banking, to transportation and medicine for almost sixty years.  Design engineering, scientific research, inventory and stock control have all been streamlined through the advent of the computer.  Where the processing of large quantities of data is necessary, computing systems are invaluable.

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  • 1943 - Proposal submitted to the Chief of Ordnance for the design of an electronic automatic computer.
  • 1943 - Funds appropriated in the amount of $61,700 for the research and development of an electronic numerical integrator and computer, hereinafter referred to an ENIAC.
  • 1947 - ENIAC becomes operational at Aberdeen Proving Ground, MD.
  • 1946-1955 - ENIAC operates successfully for 80,223 hours, performing 5,000 arithmetic operations.
  • 1951 - Remington Rand Model 409 electronic computer first demonstrated in Norwalk, Connecticut.
  • 1952 - The second, third and fourth production computers of the Model 409 were delivered to the Internal Revenue Service in Baltimore, Maryland.  This was one of the first non-military uses of the electronic computer.
  • 1952 - High-speed electronic shifter, reducing time required for numerical shifting and eliminating numerous tubes and program units, installed.
  • 1953 - EDVAC and ORDVAC begin to share computing laboratory's workload with ENIAC.
  • 1953 - IBM ships first mass-produced computer, the IBM 650.
  • 1953 - UNIVAC 120 is introduced which is a design upgrade of the Model 409.
  • 1955 - Power to ENIAC removed.
  • 1956 - Transistors used to replace vacuum tubes in computers, advent of the miniaturization of electronics.
  • 1957 - Kenneth Olsen founds Digital Equipment Corp., which will later become a major network computer manufacturer on par with the likes of IBM.
  • 1959 - IBM introduces the first solid state transistorized computer, the IBM 7090.
  • 1962 -UNIVAC 1004 developed, combined reading, processing and printing in one high-speed unit.
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Following are sites that have information on the development of mainframe computers:

  • A history of computing resources - This site was written by Robert McCordie in 1998 and provides information and links to early computers, mainframe computer history sites, home computer history sites and general computer history sites.
  • ENIAC Museum Online - The University of Pennsylvania Web site devoted to the 18 month celebration of the invention and enduring impact of ENIAC, the world's first electronic, large scale, general-purpose computer, activated at the University of Pennsylvania in 1946.
  • BESM Nostalgia Page - This web site was written by Leonid A. Broukhis in 1997 and provides a detailed history of the Soviet mainframe computer known as the Bol'shaya Ehlektronno-Schetnaya Mashina or the "Big Electronic Calculating Machine."
  • The Eniac Story
  • ENIAC—monster and marvel (anniversary news story)
  • Analog Computer Museum and History Center - This site provides information on the development of the Analog Computer  by Doug Coward.  It is currently under construction.
  • A Journey Through the History of Computers - This detailed timeline lists events in computer development from 500 b.c. to 1998. The timeline contains hundreds of entries.  From the Computing Dictionary - 3rd Edition December 1998• Vol.2 Issue 4.
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  • Martin Davis, The Universal Computer:  The Road from Leibniz to Turing
  • Scott McCartney, ENIAC: The Triumphs and Tragedies of the World's First Computer
  • Peggy Aldrich Kidwell and Paul Ceruzzi, Landmarks in Digital Computing:  A Smithsonian Pictorial History
  • Brian Randell, The Origins of Digital Computers
  • William Aspray, John Von Neumann and the Origins of Modern Computing
  • Mark W. Greenia, History of Computing: An Encyclopedia of the People and Machines that Made Computer History
  • Georges Ifrah, et al, The Universal History of Computing : From the Abacus to the Quantum Computer
  • Martin Campbell-Kelly, William Aspray (Contributor), Computer : A History of the Information Machine (The Sloan Technology Series)
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The Microprocessor
The PC Revolution
Bill Gates

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