Atanasoff–Berry computer

The Atanasoff -Berry Computer ( "ABC ") was the first electronic digital computer, built by John Atanasoff and Clifford Berry in the years 1937 to 1941 at Iowa State College. The machine was based on the binary number system. Its sole purpose was to solve large systems of linear equations. A computer in the modern sense was not the ABC, because he was not programmable.

The tube 1937 designed computer was able to simultaneously process 29 linear equations and has been successfully tested. As its inventor in 1942 due to war operations left the university, but the mechanism was still unreliable and prone to failure. Many important elements of modern computer technology were used for the first time at the ABC, as building blocks for binary arithmetic.

John Atanasoffs work only became known in 1960 to a broad public. At this time it went in a patent dispute over the question of who had developed the first automatic electronic digital computers in the United States of America. As such, the ENIAC is usually traded, but a U.S. District Court ruled in 1973 in a controversial, but unchallenged ruling that the ENIAC patents would be invalid, because the ABC was to be regarded as the first computer.

Atanasoff was the National Medal of Technology, awarded at a ceremony at the White House by U.S. President George HW Bush on 13 November 1990.

Technology

Even if not all the criteria that characterize modern computers were met, but three important aspects have been implemented:

Memory drum were used for data storage, which had a total storage capacity of about 3000 bits. Per second, about 30 arithmetic operations ( additions / subtractions ) could be carried out.

User input made ​​via punch card for output, there was a display on the front. As an intermediate memory served webs that could describe the device and read back, an error-prone storage technology, for as you still knew no parity bits, could not tell you when a written value is incorrectly read again. The error rate was one error per 100,000 operations.

Replica

The original ABC was disposed of when the University of Iowa to the basement, where he had built, converted into classrooms. All that was left was a single memory drum. 1997 managed a team of researchers at Ames Laboratory, which is located on the campus of Iowa State University to complete a functional replica. This replica last doubts about their functioning have been resolved. The cost of this project amounted to U.S. $ 350,000. The new ABC is now in the Durham Center for Computation and Communication at Iowa State University as part of a permanent exhibition for the public.

Comparison with other early computers

• Abacus
• Individual machine
• History of computer science