ENIAC in Action

From History of Computing

ENIAC in Action

Making and Remaking the Modern Computer

By Thomas Haigh, Mark Priestley and Crispin Rope

The history of the first programmable electronic computer, from its conception, construction, and use to its afterlife as a part of computing folklore.





The history of the first programmable electronic computer, from its conception, construction, and use to its afterlife as a part of computing folklore.

Conceived in 1943, completed in 1945, and decommissioned in 1955, ENIAC (the Electronic Numerical Integrator and Computer) was the first general-purpose programmable electronic computer. But ENIAC was more than just a milestone on the road to the modern computer. During its decade of operational life, ENIAC calculated sines and cosines and tested for statistical outliers, plotted the trajectories of bombs and shells, and ran the first numerical weather simulations. ENIAC in Action tells the whole story for the first time, from ENIAC's design, construction, testing, and use to its afterlife as part of computing folklore. It highlights the complex relationship of ENIAC and its designers to the revolutionary approaches to computer architecture and coding first documented by John von Neumann in 1945.

Within this broad sweep, the authors emphasize the crucial but previously neglected years of 1947 to 1948, when ENIAC was reconfigured to run what the authors claim was the first modern computer program to be executed: a simulation of atomic fission for Los Alamos researchers. The authors view ENIAC from diverse perspectives—as a machine of war, as the “first computer,” as a material artifact constantly remade by its users, and as a subject of (contradictory) historical narratives. They integrate the history of the machine and its applications, describing the mathematicians, scientists, and engineers who proposed and designed ENIAC as well as the men—and particularly the women who—built, programmed, and operated it.


Out of Print ISBN: 9780262033985 366 pp. | 7 in x 9 in 43 b&w illus.


$25.00 X ISBN: 9780262535175 366 pp. | 7 in x 9 in 43 b&w illus.


  • Bad history makes false claims about firsts. Good history makes true claims about firsts. Great history, however, doesn't primarily concern itself with firsts at all (though it may necessarily deal with them as part of the subject matter), but redirects us to ask deeper, more meaningful questions. Great history, like the work of Tom Haigh, Mark Priestley, and Crispin Rope, goes beyond the baseline of facts, the high-school textbook version, into a whole new realm of interpretation.

    Computer History Museum

  • ...a particularly important, thorough, and balanced account, a major contribution to the history of early computing, and certainly required reading for any student of the subject.

    SIAM News

  • [A] nuanced, engaging and thoroughly researched account of the early days of computers, the people who built and operated them, and their old and new applications.... [T]he creativity and intelligence of good historians writing books such as ENIAC in Action will keep us informed and entertained.


  • Haigh et al. for the first time tell the whole story of the first computer (digital, electronic, programmable), supported by impressive research. Their book will no doubt become the standard reference for all things ENIAC.

    Joseph F. Grcar

    SIAM Review


  • I have a shelf full of books about the ENIAC, the electronic computer whose completion in 1945 heralded the birth of the Information Age. But until now, none have captured the many facets of that machine and its place in history. Basing their book on a wealth of archival research, Haigh, Priestley, and Rope for the first time tell this story in its fullest measure.

    Paul E. Ceruzzi

    Chairman, Division of Space History, National Air and Space Museum, Smithsonian Institution

  • ENIAC in Action delivers a breathtakingly original, approachable, and at times even funny reinterpretation of the dawn of computing. More than the story of one hugely important machine, told from technical, institutional, and personal perspectives, it illuminates the invention of the modern computer, the development of programming, the transformation of scientific practice around new technology, and the transition from the mathematical technology of World War II to the simulations culture of the early Cold War.

    Joseph November

    Associate Professor of History, University of South Carolina

  • This book should be read by anyone who wants to understand the initial evolution of our modern abstraction of what a computer is. The authors weave a convincing account of how ENIAC's architecture was originally developed and then continued to evolve. They combine a careful reading of the documentation and lab notebooks generated during ENIAC's development with a deep understanding of the architectural issues behind competing possible implementations.

    Mitch Marcus

    RCA Professor of Artificial Intelligence, Department of Computer and Information Science, University of Pennsylvania