Atanasoff–Berry computer

The Atanasoff–Berry computer (ABC) was the first automatic electronic digital computer. It was made when technology was still growing, so it had some limits. Even though it could not change to do different jobs like later computers, it was very important for the history of computing.

One big reason the ABC matters is that it was the first machine to use vacuum tubes for doing math. Before this, computers used slower ways that took more time. Using tubes helped make computing faster and influenced later machines.

Other early computers, like Konrad Zuse's Z1 computer and the Harvard Mark I, used different, slower ways. Even the Colossus computer from a few years later, which could be programmed, used similar tube technology first tried in the ABC. So, the Atanasoff–Berry computer was an important step in making the fast, electronic computers we use today.

Overview

The Atanasoff–Berry computer was made in 1937 by John Vincent Atanasoff, a professor at Iowa State College, and his student Clifford Berry. It was built to solve math problems with simple answers and was tested in 1942. But some parts did not work well, and work stopped when Atanasoff went away for World War II.

This early machine had ideas that are used in computers today, like using two-number math and electronic parts to switch on and off. But it could only do one job and could not change tasks, so it is different from computers we use now. The importance of this machine became known much later, especially when people talked about who made the first electronic computer.

Design and construction

The Atanasoff–Berry computer was built by John Atanasoff and Clifford Berry from 1939 to 1942. It was made in the basement of the physics building at Iowa State College. This machine used vacuum tubes and capacitors to do calculations, which was new at the time. It could do about 30 additions or subtractions each second.

Unlike later computers, the Atanasoff–Berry computer could not be programmed to do different tasks. A person had to set it up for each problem. It could only solve small problems directly and used paper sheets to keep bigger results between steps. People used special cards to give it information and read the answers from a display on the machine.

Function

The Atanasoff–Berry computer, or ABC, was made to solve a special kind of math problem. It could handle problems with up to 29 equations, which was very challenging at the time.

The machine could take two equations and remove one of the variables. This step had to be done by hand for each equation, making the problem smaller each time. This process was repeated until only one equation was left. George W. Snedecor was likely the first to use an electronic digital computer to solve real math problems, and he sent many problems to Atanasoff for the ABC to work on.

Patent dispute

In 1947, two scientists named J. Presper Eckert and John Mauchly asked for a patent for a digital computing device called the ENIAC. This surprised John Atanasoff because John Mauchly had seen Atanasoff’s earlier machine, the ABC, in 1941.

Later, a company called Honeywell tried to cancel the ENIAC patent. In 1973, a court decided the ENIAC patent was not valid because it used ideas from Atanasoff’s computer. The judge said Eckert and Mauchly did not invent the electronic digital computer first. They got their ideas from Atanasoff.

Replica

The original Atanasoff–Berry computer was taken apart in 1948. Most of its parts were thrown away, but one memory drum was kept.

In 1997, researchers made a working copy of the Atanasoff–Berry computer. They were led by Delwyn Bluhm and John Gustafson from the Ames Laboratory at Iowa State University. This copy cost $350,000 to make. It was first shown at Iowa State University and later moved to the Computer History Museum.