Rebuilding the ABC: A Personal Account

John Gustafson and ABC

John Gustafson, an ISU applied math alum, next to the replica of the Atanasoff-Berry Computer.

John Gustafson (MS Applied Math ’81; PhD Applied Math ’82) shares his memories, in his own words, about being part of the team that reconstructed the Atanasoff-Berry Computer (ABC):

Getting involved: I got involved in the project as someone who had created a special-purpose computer (the FPS-165/MAX) to solve linear equations in my first job at Floating Point Systems. A colleague mentioned how similar our approach was to the Atanasoff-Berry Computer and my eyes went wide when I discovered it was developed at Iowa State. That’s when I vaguely remembered the displays in the Physics building about how Iowa State was where the first electronic digital computer was developed, and at the time I dismissed it as an implausible boast. Then I found out it was true, and wanted to make sure the rest of the world found it out, too!

Joining the team: I joined the reconstruction team when it first formed and was led by Del Bluhm. After the overall physical construction was complete, I was put in charge of the effort to make the ABC reconstruction actually perform as it did in 1942.

Getting it to perform: It had to be completely rewired. For example, the original wiring was done without any checking for correctness. Charles Shorb was the grad student who did almost all of that work, and did it brilliantly and with dedication. He and I were the ones who demonstrated the working replica at the National Press Club at the end of the project. Charles and I are the ones in the YouTube videos that show the ABC in operation. I’ve presented papers at a number of conferences regarding the ABC and recently assisted bestselling author Jane Smiley with her biography of Atanasoff, which comes out from Random House in October 2010.

Importance of the ABC: To me, the ABC represents the cornerstone invention of modern computing. There were many pioneering machines in the late 1930s and 1940s, but the ABC has so many innovations at once that are still used in modern computing, and unlike the secret or obscure machines, the ABC led to the ENIAC and EDVAC, which led to, well, everything. This is one of the greatest inventions of the 20th century, no question.