Iowa State scientists unveiled a full-scale replica of the Atanasoff-Berry Computer (ABC) at the Supercomputing ’96 Conference in Pittsburgh, Nov. 18.

The ABC, the first electronic digital computer, was built by John V. Atanasoff, an Iowa State professor of physics and mathematics, and Clifford Berry, a graduate student, at ISU in the late 1930s and early ’40s.

It was never patented and eventually was discarded.

The replica is being built to honor the legacy of the two computing pioneers. When completed, the replica will be a working model of the original computer.

Institute for Physical Research and Technology director Joel Snow, said there is still some more work to do on the replica to get it up and running.

The replica team, which includes scientists and engineers from the Ames Laboratory, IPRT and ISU, plans to finish work and test the replica by the spring of 1997.

An official unveiling and demonstration will take place this spring.

“We hope by early spring, that it will be not only completely functional but that whatever bugs that it has in it will have been taken care of,” Snow said.

For those familiar with algebra, the original machine was designed to solve sets of simultaneous linear equations, Snow said.

Although it could solve as many as 29 equations, with 25 unknowns, it was probably used to solve only a fraction of that number.

Scientists hope to be able to solve up to 5 equations with the replica.

“We would rather first see if it can solve 3 equations and 3 unknowns, or 5 equations and 5 unknowns,” Snow said.

“We know the original machine was used to solve relatively moderate sized problems.”

Planners of the Supercomputing ’96 Conference, which ends today at the Lawrence Convention Center in Pittsburgh, decided to make the conference a celebration of the first 50 years of supercomputing, Snow said.

“This really was the first supercomputer,” he said. “It was the only electronic digital computer at that time, even though it was designed to solve just one type of problem.”

The ABC computer was important not because it was especially useful, but because it laid the technological groundwork for today’s computers.

“It was still really an experimental machine, but it was loaded with important innovations, many of which show up in today’s modern computers,” Snow said.

These include using a binary system of mathematics, having separate memory and computing functions, having a regenerative memory, using circuits for logical addition and subtraction, and having modular design construction.

Thus, the ABC played an important role in the technological revolution of the 20th century.

Ames Laboratory, a member of Iowa State’s Institute for Physical Research and Technology, is a U.S. Department of Energy research laboratory operated by the university for the federal government.