Iowa State University officials successfully gave the first public demonstration of a full-scale replica of the first electronic digital-computer Wednesday at the National Press Club in Washington D.C.

The replica is a working model of the Atanasoff-Berry computer (ABC) built in the basement of the Physics Building at ISU from 1939 to 1942.

The ABC was originally built by John V. Atanasoff, an ISU professor of physics and mathematics, and Clifford Berry, a graduate student.

President Martin Jischke, who was present for the unveiling, said in a press release, “We feel it is extremely important to have built the replica and honor these two pioneers who set the course of modern computing with this machine.”

John Gustafson, head of the replica team, said the demonstration went flawlessly.

The replica was given two equations and two unknowns to compute, Gustafson said.

He said it was a fairly ambitious problem, although the computer was designed to perform simultaneous equations.

“Almost every part of the machine has to work perfectly, so it was a good stress test,” he said.

The replica passed the test.

“I told them it was going to give an answer of three, and they all heard it go click, click, click,” Gustafson said. “It worked in 1940, and it worked now.”

Steve Sullivan, university relations, said more than 50 people attended.

“A lot more people are going to know about it because of the press coverage,” he said.

The ABC unveiling received international coverage, with representatives present from a Japanese newspaper, a Russian television station, science trade magazines, CNN, National Geographic and NBC, among others.

Members of the Atanasoff family were also present, including John Vincent Atanasoff II, who visited ISU last summer.

“The interest in it is incredibly high,” Sullivan said. “We’re a science and technology university; that’s a major part of our image, and this just contributes greatly to that.”

The computer was transported by truck to Washington D.C.

“There was some concern with having it shipped across the country,” Sullivan said.

Gustafson said they did a very nice job of transporting it, but it still needed repair work.

A team of three people spent 48 hours repairing the computer, Gustafson said. “It was a massive effort to make it work,” he said.

Sullivan said he admires the time spent by the team researching and finding parts for an accurate reproduction.

The original ABC was never patented, and eventually it was discarded.

The team relied on fragmentary documentation, grainy pictures, a few original pieces and the memories of those who were part of the original project.

The team tried to make the replica as true to the original as possible.

Gustafson said he would admit one change from the original design — the replica is only 33 inches deep, while the original was 36 inches deep. This way, he explained, it can fit through a standard door.

Gustafson said the original ABC was boxed in when walls were built in the basement of the Physics Building, and the team wanted to make sure that never happened to the replica.

“It just barely fit into the freight elevator here [in Washington D.C.,” he said. It is more than six feet wide and stands as tall as a desk, he said.

“This is a very important part of the university heritage and its history, its tradition,” Sullivan said.

About $350,000 of private funding and a lot of volunteer time went into making the replica, Gustafson said.

Atanasoff received $5,000 for parts in addition to his salary when constructing his original computer, he said.

“It’s almost impossible to put a price on reclaiming history like this,” Sullivan said.

Work on the replica began in 1994. It was a year and a half of research and reverse engineering before the team started cutting metal, Gustafson said.

The replica was completed and ran for the first time about two months ago, but had problems with reliability and parts wearing out, he said.

“I don’t think I did get nervous,” Gustafson said. “I did breathe a kind of deep sigh of relief when it did do that [computation].”

The replica will spend the next year touring Iowa and is scheduled for a display in Ames on Wednesday, Oct. 22.

“People all over the state are going to be able to see it, kids especially,” Sullivan said.