Iowa State University

Inside Iowa State
Jan. 9, 1998

ABC stops at the Brunnier next week

by Skip Derra

The ABC replica, an authentic working replica of the Atanasoff-Berry Computer, will be displayed at the Brunnier Museum Jan. 13-18.

The Brunnier's hours are 11 a.m. to 4 p.m. Tuesday through Friday, 5 to 9 p.m. Thursday, and 1 to 4 p.m. Saturday and Sunday. Admission is free to the museum, located on the second floor of the Scheman Building.

After the Brunnier exhibit, the ABC replica will continue its Iowa tour, which includes stops in Cedar Rapids on Jan. 28, the Quad Cities on Jan. 30, Sioux City on Feb. 23, Waterloo on March 23 and Mason City on May 18. The first public viewing of the replica was at the National Press Club in Washington, D.C., last October.

The desk-sized ABC has faint resemblance to today's computers. It weighed 750 pounds, performed 0.06 operations/second (compared to 10 billion operations/second today) and had a memory storage capacity of 3,000 bits (compared to 100 billion bits today). Its mechanical features included rotating drums (for data storage), a read/write system that recorded numbers by scorching marks into cards, and vacuum tubes that flickered as it performed computations.

John V. Atanasoff, an Iowa State professor of physics and mathematics, and Clifford Berry, a graduate student, built the world's first electronic digital computer in the period of 1939-42. Work on the original ABC was interrupted by World War II and the computer never was patented. The original ABC eventually was discarded. The replica was built to honor the genius of Atanasoff and Berry.

Scientists, technicians and students at Ames Laboratory retraced the steps taken by Atanasoff and Berry. The team took painstaking care in using vintage computer parts, like 1940s vacuum tubes, brushes and card punches of that era, most of which disappeared as technology evolved. The replica team spent hundreds of hours ferreting out details on how the original operated and securing authentic parts.

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