The Atanasoff-Berry Computer In Operation


[Recorded: 1999]
The Atanasoff-Berry Computer (ABC) occupies a special place in the history of computing in part for its technical accomplishments but also for being at the center of a landmark legal case. It was built by Iowa physics professor John Vincent Atanasoff and graduate student Clifford Berry.

Technically, the ABC was an electronic equation solver. It could find solutions to systems of simultaneous linear equations with up to 29 unknowns, a type of problem encountered in Atansasoff’s physics work. Construction of the ABC began in 1938 at Iowa State College (now University) in Ames, Iowa. It was about the size of a large desk, weighed 750 lbs, computed 0.06 operations per second (sustained) and had 0.37 KB of memory. It could also do 30 add/subtract operations per second. While not a computer in the modern sense (since it did not store its own program), it pioneered various techniques in digital computer design including binary arithmetic, parallel processing, and electronic (vacuum tube) switching elements. The device was completed in 1942 and worked, although its spark-gap printer mechanism needed further development.

The legal dimension to the ABC story involves a lawsuit between two computer makers, Honeywell and Sperry-Rand. In 1967, Honeywell sued Sperry over their ENIAC patents using the ABC as evidence of prior art. (ENIAC was an early digital electronic calculator completed in 1946). After years of proceedings, on October 19, 1973 the judge in the case, Earl R. Larson, agreed with Honeywell that some of the ideas in the ENIAC, which had been considered the ‘world’s first computer,’ in fact came from Atanasoff during a four-day visit ENIAC designer John Mauchly made to Atanasoff at Iowa State before ENIAC was designed. There was also months of correspondence between the two in which Mauchly expressed his desire to build a similar device. The net result of this judgment was that no one owned the patent on the computer: it was free to be developed by all. Gordon Bell has called this the ‘dis-invention of the computer.’

In 1993, Iowa State University began a historically-accurate reconstruction of the ABC, which it finished in 1997. The project cost $360,000 and involved about a dozen people in its realization. This film shows the ABC Reconstruction in operation, solving a simple algebra problem.

Catalog number: 102781093
Lot number: X6054.2011

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  1. Phasor Systems says

    Having problems with circuits? Try circuit solver seek androidcircuitsolver on google!

  2. Salam Waddah says

    but can it run doom?

  3. Цанко Калканджиев says

    John Vincent Atanasov! His father its from Bulgaria! I prоud to be Bulgarian!?

  4. TheKolobur88 says

    Atanasoff was a prominent American/Bulgarian inventor who took pride in his Bulgarian heritage and maintained strong ties to his ancestral home of Bulgaria. From a letter he wrote, "To My Fatherland":"I have always felt that the Bulgarian heritage in my blood has kept my spirit. And now, as I am growing old, I am even happier for my good fortune. My people have met me warmly and have given me a high prize, the Cyril and Methodius Order First Class, my first public recognition. I was elected a member of the Bulgarian Academy of Sciences and I am in touch with many friends in Bulgaria."

  5. Leydi Samaniego Jibaja says

    Computacion ABC

  6. Chang Noi says

    I have the tablet version.

  7. GH1618 says

    It is pointless to argue about who invented the computer, particularly by arguing what constitutes a computer. Atanasoff himself said "I have always taken the position that there is enough credit for everyone in the invention and development of the electronic computer.”Just remember people for what they contributed and when.

  8. kae4466 says

    fascinating. its amaiZing what was done with zinc plated vacuum ttubes

  9. DarthChrisB says

    "Institute for physical reascerch" WHAT?

  10. Хлебников Денис says

    Some how it's ramindes me a atmel's 8bit mcu's

  11. The Lavian says

    Insert standard Doom / Crysis joke here.

  12. GGaben says

    First digital computer is colossus

  13. Magandang Buhay says

    2:24 nice ROM

  14. Matthew Parets says

    The machine was astounding, but it wasn't the first electronic digital computer. It wasn't a general purpose computer, and it wasn't entirely solid state. So as a member of the historical nit-pickers society I have to pass on the ABC and award the prize to the ENIAC. Arguments like this are why the ABC eventually lost the patent.

  15. Kandi Klover says

    Spark Gap printer haha good way to get a $10,000 NAL from the FCC if you don't properly shield that thing before running.

  16. Ron Wolf says

    Amazing to see the ABC in action. And the effort that you guys put in to recreating this! Wow! Much less Atanasoff's building it in the first place!!

  17. A.A says

    Use a computer instead of this big noise making train

  18. Paegr says

    Can it run Doom?

  19. Wun Hung Lo says


  20. Mike Schwab says

    I punched cards for a class in 1982. And don't forget the hanging chads in Florida 2000 election recount.

  21. N1csBG says

    greetings from Bulgaria this pc is created and designed in Bulgaria and is from Bulgarian

  22. 1906Farnsworth says

    A marvelous machine. I especially like the way none of the controls are marked. You just have to know what they do. Steam locomotives are the same way. All you see is a couple of dozen red handles. Turn the wrong one, and everybody dies. Less at stake with the computer.

  23. Maly Pivo says


  24. johneygd says

    These computers were semi digital.

  25. Mum Blic says

    Looks to me more like a semi digital calculator.What I want to know is: What was the true first computer. It's needs to have a processor that has an instruction set and a program counter.

  26. Paul Kalogiannis says

    This can't be recorded in 99. It looks like the 80s?

  27. Cold Spirit says

    Without abc there weren't going to be invented computers.Abc is the very first PC

  28. Bernard Gunderson says

    We need to be teaching kids how to solve these problems on there own instead of relying on gadgets to do all the work.

  29. Slimword says

    The genius and engineering behind this machine is amazing.

  30. Fishing ConElLoko says

    so they made a machine that can do it slower then we can do by hand????

  31. barracuda7018 says

    The computer was invented in the U.S.A..!!!!!

  32. allan egleston says

    literaly 1 and 0 or on and off state . this gives a good analog reference for me to understand how my " modern" computer works . what is old is new again. a lot ot the tech reminds me of old style player piano rolls and such.

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