ABC Reconstruction

ABC Reconstruction, 1994-1997

As court cases often do, Honeywell vs. Rand inspired debate and discussion. Since there was no actual ABC computer produced as evidence (although the Sperry team did construct a "breadboard" model), questions arose concerning what kind of machine the ABC actually was. Some called it a "special purpose" computer, therefore distinguishing the ENIAC and other later machines as "general purpose," and therefore more important to the historical record. John Gustafson wrote in The Quest for Linear Equation Solvers that "even with 18,000 vacuum tubes, the ENIAC could only hold 20 10-digit numbers, fewer than the ABC's 30 15-digit numbers," and raised the question of whether the ENIAC itself could be termed a "special purpose" computer. Others claimed that the ABC was never fully operational, and therefore could not possibly be considered the first electronic digital computer. In order to explore these issues and other mysteries about the purpose and functionality of the original ABC, a team of engineers, scientists, and students at Iowa State University came together to build a reconstruction/replica of the ABC computer based on the records that were available, in particular JVA's writings on the machine during his search for funding to build it and later to patent it.

Del Bluhm wrote about his experience with the project and all of the contributors that made it possible in Documenting the ABC Replica Project and its Contributors, published in the Computer Science Department's alumni magazine, Atanasoff Today, in spring 2013. John Gustafson documents the process in his paper, Reconstruction of the Atanasoff-Berry Computer, presented in August 1998 in Paderborn, Germany and later appeared in the Annals of the History of Computing.

Team Members

The project was initiated and championed by Delwyn Bluhm, then Manager of Engineering Services at Ames Laboratory, and George Strawn, former director of the Iowa State University Computation Center and Chair of the ISU Department of Computer Science. Bluhm and Strawn obtained initial funding from Charles Durham, a former student of John V. Atanasoff and distinguished alumni of ISU. The original ABC was built with a grant from the Iowa State College for around $5,000. The ABC Reconstruction was completed in 1997, and cost around $300,000. Funding for the project was obtained entirely through private sources.

Above: Early champions of the ABC Reconstruction project, initated by George Strawn and Del Bluhm.

Left: The ABC Reconstruction was unveiled to the public at Supercomputing '96 in Pittsburgh, Pennsylvania, November 17-22.

Watch a demonstration of the ABC Reconstruction in action.

Photographs presented here are courtesey of the Scalable Computing Laboratory, Iowa State University

Reconstruction Team Roster

(Titles listed indicate status or employment at the time of the reconstruction project)

Project Directors

Del Bluhm, Ames Laboratory
John Gustafson, Ames Laboratory

Electronic Design Team

Al Read, Iowa State University
Gary Sleege, Ames Laboratory
Mike Stock, student, Iowa State University

Electronic Supervision

John Erickson, Ames Laboratory

Electronic Fabrication

Lee Harker, Ames Laboratory
John Hjortshoj, Ames Laboratory
Jerry Musselman, Ames Laboratory
Clare Tweedt, Ames Laboratory
Terry Forgette, student, Iowa State University

Mechanical Design

Dave Birlingmair, Ames Laboratory
Jennifer Augestein, student, Iowa State University
Jeff Etringer, student, Iowa State University

Mechanical Supervision

Jerry Hand, Ames Laboratory

Mechanical Fabrication

Jim Berninghaus, Ames Laboratory
Charlie Bug, Ames Laboratory
Steve Lee, Ames Laboratory
Bill Wing, Ames Laboratory

Debugging and Testing

John Erickson, Ames Laboratory
Guy Helmer, Ames Laboratory
Gary Sleege, Ames Laboratory
Charles Shorb, student, Iowa State University

Review Team Leader

George Burnet, Iowa State University

Review Team

Murray Blackwelder, Iowa State University
Arthur Burks, University of Michigan
Joel Snow, Iowa State University
George Strawn, Iowa State University/NSF

Public Relations

John Anderson, Iowa State University
Carole Custer, Iowa State University
Skip Derra, Iowa State University
Geni Greiner, Iowa State University Foundation
Steven Karsjen, Ames Laboratory

Project Administration

Connie Bates, Ames Laboratory
Jeanine Crosman, Ames Laboratory