At that time, the ENIAC was considered to be the first computer in the modern sense, but in 1973 a U. S. District Court invalidated the ENIAC patent and concluded that the ENIAC inventors had derived the subject matter of the electronic digital computer from Atanasoff ( see Patent dispute ).

J. Presper Eckert and John Mauchly were the first to patent a digital computing device, the ENIAC.

The United States District Court for the District of Minnesota released its judgement on October 19, 1973, finding in Honeywell v. Sperry Rand that the ENIAC patent was a derivative of John Atanasoff's invention.

The case was legally resolved on October 19, 1973 when U. S. District Judge Earl R. Larson held the ENIAC patent invalid, ruling that the ENIAC derived many basic ideas from the Atanasoff – Berry Computer.

* The ENIAC patent trial

The ABC was largely forgotten until it became the focus of the lawsuit Honeywell v. Sperry Rand, the ruling of which invalidated the ENIAC patent ( and several others ) as, among many reasons, having been anticipated by Atanasoff's work.

A number of improvements were also made to ENIAC after 1948, including a primitive read-only stored programming mechanism using the Function Tables as program ROM, an idea included in ENIAC patent and proposed independently by Dr. Richard Clippinger of the BRL.

For a variety of reasons ( including Mauchly's June 1941 examination of the Atanasoff – Berry Computer, prototyped in 1939 by John Atanasoff and Clifford Berry ), US patent 3, 120, 606 for ENIAC, granted in 1964, was voided by the 1973 decision of the landmark federal court case Honeywell v. Sperry Rand, putting the invention of the electronic digital computer in the public domain and providing legal recognition to Atanasoff as the inventor of the first electronic digital computer.

Eckert, a co-inventor of ENIAC, discusses its development at the University of Pennsylvania's Moore School of Electrical Engineering ; describes difficulties in securing patent rights for ENIAC and the problems posed by the circulation of John von Neumann's 1945 First Draft of the Report on EDVAC, which placed the ENIAC inventions in the public domain.

Travis describes the ENIAC project at the University of Pennsylvania ( 1941 – 46 ), the technical and leadership abilities of chief engineer Eckert, the working relations between John Mauchly and Eckert, the disputes over patent rights, and their resignation from the university.

Eckert and Mauchly's agreement with the University of Pennsylvania was that Eckert and Mauchly retained the patent rights to the ENIAC but the University could license it to the government and non-profit organizations.

Eckert, a co-inventor of the ENIAC, discusses its development at the University of Pennsylvania's Moore School of Electrical Engineering ; describes difficulties in securing patent rights for the ENIAC and the problems posed by the circulation of John von Neumann's 1945 First Draft of the Report on EDVAC, which placed the ENIAC inventions in the public domain.

* issued in 1964 for ENIAC ( TIFF images ), also PDF version ( 18, 305 kB, 207 pages )

* Honeywell v. Sperry Rand, a landmark U. S. federal court case that in April 1973 invalidated the 1964 patent for the ENIAC

It was not a Turing complete computer, which distinguishes it from more general machines, like contemporary Konrad Zuse's Z3 ( 1941 ), or later machines like the 1946 ENIAC, 1949 EDVAC, the University of Manchester designs, or Alan Turing's post-War designs at NPL and elsewhere.

The idea of a stored-program computer was already present in the design of J. Presper Eckert and John William Mauchly's ENIAC, but was initially omitted so that it could be finished sooner.

On June 30, 1945, before ENIAC was made, mathematician John von Neumann distributed the paper entitled First Draft of a Report on the EDVAC.

This overcame a severe limitation of ENIAC, which was the considerable time and effort required to reconfigure the computer to perform a new task.

A dozen of these devices were built before their obsolescence was obvious ; the most powerful was constructed at the University of Pennsylvania's Moore School of Electrical Engineering, where the ENIAC was built.

The third stream of computer development was Eckert and Mauchly's ENIAC and EDVAC, which was widely publicized.

The US-built ENIAC ( Electronic Numerical Integrator and Computer ) was the first electronic general-purpose computer.

ENIAC was unambiguously a Turing-complete device.

A " program " on the ENIAC, however, was defined by the states of its patch cables and switches, a far cry from the stored program electronic machines that came later.

The first actual implementation of a Turing-complete machine appeared in 1941: the program-controlled Z3 of Konrad Zuse, but the first machine explicitly designed to be Turing complete and widely appreciated as being universal was the 1946 ENIAC.

Later work confirmed that tube unreliability was not as serious an issue as generally believed ; the 1946 ENIAC, with over 17, 000 tubes, had a tube failure ( which took 15 minutes to locate ) on average every two days.

In 1948, ENIAC was moved from the University of Pennsylvania's Moore School of Electrical Engineering, where it had been conceived and designed by John Mauchly and J. Presper Eckert, to the Ballistic Research Laboratory in Aberdeen, Maryland.

This architecture greatly facilitated programming, and on September 16, 1948, ENIAC was first run as a stored-program computer.

This approach was made possible by his access to computers: ENIAC at Aberdeen, a new computer, MANIAC, at Princeton, and its twin, which was under construction at Los Alamos.

The ABC had been examined by John Mauchly in June 1941, and Isaac Auerbach, a former student of Mauchly's, alleged that it influenced his later work on ENIAC, although Mauchly denied this ( Shurkin, pg.

However, up to the 1940s, many subsequent designs ( including Charles Babbage's machines of the 1822 and even ENIAC of 1945 ) were based on the decimal system ; ENIAC's ring counters emulated the operation of the digit wheels of a mechanical adding machine.

ENIAC co-inventor John Mauchly examined the ABC in June 1941, and its influence on the design of the later ENIAC machine is a matter of contention among computer historians.

Late in the war, under the sponsorship of von Neumann, Frankel and Metropolis began to carry out calculations on the first general-purpose electronic computer, the ENIAC.

Immediately after the war he worked on the ENIAC project, in 1945 and 1946.

ENIAC was shut down on November 9, 1946 for a refurbishment and a memory upgrade, and was transferred to Aberdeen Proving Ground, Maryland in 1947.

Although the Ballistic Research Laboratory was the sponsor of ENIAC, one year into this three-year project John von Neumann, a mathematician working on the hydrogen bomb at Los Alamos, became aware of this computer.

After the program was figured out on paper, the process of getting the program " into " ENIAC by manipulating its switches and cables took additional days.

Four ENIAC panels and one of its three function tables, on display at the School of Engineering and Applied Science at the University of Pennsylvania

There are also seven panels and detailed history and explanation of ENIAC functions using text, graphics, photographs and interactive touch screen on display at the Perot Group in Plano, Texas.

* Mauchly, John, The ENIAC ( in Metropolis, Nicholas, J. Howlett, Gian-Carlo Rota, 1980, A History of Computing in the Twentieth Century, Academic Press, New York, ISBN 0-12-491650-3, pp. 541 – 550, " Original versions of these papers were presented at the International Research Conference on the History of Computing, held at the Los Alamos Scientific Laboratory, 10 – 15 June 1976.

An in-depth, technical discussion on ENIAC, including the thought process behind the design.

Herman Heine Goldstine ( September 13, 1913 – June 16, 2004 ) was a mathematician and computer scientist, who was one of the original developers of ENIAC, the first of the modern electronic digital computers.

The First Draft of a Report on the EDVAC ( commonly shortened to First Draft ) was an incomplete 101-page document written by John von Neumann and distributed on June 30, 1945 by Herman Goldstine, security officer on the classified ENIAC project.