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 It was built by J. Presper Eckert and John W. Mauchly at the Moore School of Electrical Engineering of the University of Pennsylvania under contract to the U.S. War Department.
The ENIAC Computer
ENIAC (Electronic Numerical Integrator And Calculator) was the first successful electronic digital computer.
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It contained 18,000 vacuum tubes.
It went into full operation in February 1946 where it successfully performed for 9 years. It was predicted that statistically it would never operate because the average rate of a tube failure was more frequent than they could isolate and replace the bad tube, but fortunately this proved wrong. Physicist John Vincent Atanasoff invented the basic digital techniques used in ENIAC.
Physically, ENIAC was large and awkward. It was designed primarily for the calculation of ballistic trajectory tables for the military.
"Where a computer like the ENIAC is equipped with 18,000 vacuum tubes and weighs 30 tons, computers in the future may have only 1,000 vacuum tubes and weigh only 1 1/2 tons."
Popular Mechanics, March 1949

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ENIAC                             U. S. Army

A REPORT ON THE ENIAC
(Electronic Numerical Integrator and Computer)

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AREPORT ON THE ENIAC
(Electronic Numerical Integrator and Computer)

 

Report of Work Under Contract No. W-670-ORD-4926
Between
Ordnance Department, United States Army
Washington, D.C.
and
The University of Pennsylvania
Moore School of Electrical Engineering
Philadelphia, PA
June 1, 1946

Included with the Operating Manual and Parts I and II of the Technical Description are all drawings (see Table 0.3 below) which are required for understanding these reports. The Maintenance Manual assumes access to the complete file of ENIAC drawings. Part I of the Technical Description is intended for those who wish to have a general understanding of how the ENIAC works, without concerning themselves with the details of the circuits; it assumes no knowledge of electronics or circuit theory. Part II is intended for those who require a detailed understanding of the circuits. Its organization, to a great extent, duplicates that of Part I so as to make cross referencing between the two parts easy. The ENIAC Operating Manual contains a complete set of instructions for operating the ENIAC. It includes very little explanatory material, and hence assumes familiarity with Part I of the Technical Description of the ENIAC. The ENIAC Maintenance Manual includes description of the various test units and procedures for testing, as well as a list of common and probable sources of trouble. It assumes a complete understanding of the circuits of ENIAC, i.e., a knowledge of both Parts I and II of the Technical Description of the ENIAC.
Ed Note This was classified material released from the U.S. Army.  Hence the formality and dryness of the report.

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The Report on the ENIAC consists of five separately bound parts, as follows:

  1. ENIAC Operating Manual
  2. ENIAC Maintenance Manual
  3. Part I, Technical Description of the ENIAC
    Volume I (Chapters I to VI)
  4. Part I, Technical Description of the ENIAC
    Volume II (Chapters VII to XI)
  5. Part II, Technical Description of the ENIAC.
 

Online Table of Contents

Part I, Technical Description of the ENIAC

Part II, Technical Description of the ENIAC.

More to come...

 

Acknowledgement and Thanks

This document has been rendered machine readable thanks to the typing efforts of Monique Nguyen, LB&B, Monique@ARL.MIL (Preface and Chapter 1) and James R. Jackson, LB&B, JJackson@arl.mil (Chapters 2, 3, and 4).

 

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