John Atanasoff Clifford Berry  Inventors of the Modern Computer Series • Table of Contents • Next Chapter Howard Aiken & Grace Hopper - Harvard Mark I ENTER

John Atanasoff Clifford Berry on the Web • John Atanasoff and Clifford Berry Biographical information on the inventors, pictures and technical drawings of the Atanasoff-Berry Computer, the patent dispute, court papers and transcripts.

"I have always taken the position that there is enough credit for everyone in the invention and development of the electronic computer" - John Atanasoff to reporters.

Professor John Atanasoff and graduate student Clifford Berry built the world's first electronic-digital computer at Iowa State University between 1939 and 1942. The Atanasoff-Berry Computer represented several innovations in computing, including a binary system of arithmetic, parallel processing, regenerative memory, and a separation of memory and computing functions.

Presper Eckert and John Mauchly were the first to patent a digital computing device, the ENIAC computer. A patent infringement case (Sperry Rand Vs. Honeywell, 1973) voided the ENIAC patent as a derivative of John Atanasoff's invention. Atanasoff was quite generous in stating, "there is enough credit for everyone in the invention and development of the electronic computer." Eckert and Mauchly received most of the credit for inventing the first electronic-digital computer. Historians now say that the Atanasoff-Berry computer was the first.

"It was at an evening of scotch and 100 mph car rides," John Atanasoff told reporters, "when the concept came, for an electronically operated machine, that would use base-two (binary) numbers instead of the traditional base-10 numbers, condensers for memory, and a regenerative process to preclude loss of memory from electrical failure.”

John Atanasoff wrote most of the concepts of the first modern computer on the back of a cocktail napkin. He was very fond of fast cars and scotch.

Atanasoff-Berry Computer

In late 1939, John Atanasoff teamed up with Clifford Berry to build a prototype. They created the first computing machine to use electricity, vacuum tubes, binary numbers and capacitors. The capacitors were in a rotating drum that held the electrical charge for the memory. The brilliant and inventive Berry, with his background in electronics and mechanical construction skills, was the ideal partner for Atanasoff. The prototype won the team a grant of $850 to build a full-scale model. They spent the next two years further improving the Atanasoff-Berry Computer. The final product was the size of a desk, weighed 700 pounds, had over 300 vacuum tubes, and contained a mile of wire. It could calculate about one operation every 15 seconds, today a computer can calculate 150 billion operations in 15 seconds. Too large to go anywhere, it remained in the basement of the physics department. The war effort prevented John Atanasoff from finishing the patent process and doing any further work on the computer. When they needed storage space in the physics building, they dismantled the Atanasoff-Berry Computer.

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