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The Intel Museum ( This is where our exhibit is on display

The Computer History Museum ( This is where I spoke on Monday 11/13/2006. They gave us access to an engineering prototype of the Busicom 141-PF calculator so we could extract the software from the ROMs.

Federico Faggin ( Intel 4004 co-inventor and chip designer. He served as an advisor during the early stages of the museum project.

Masatoshi Shima ( the only non-Intel co-inventor, working for Intel's client Busicom (aka NCM), he was the overall systems designer for the calculator, and he was a very significant contributor to the final 4004 architecture. He also wrote all the calculator software.

Fred Huettig ( designed the electronics for the 4004 exhibit.

Brian Silverman ( and his brother Barry Silverman reverse-engineered the 4004 from the schematics as well as the Busicom calculator software from the binaries.

Christian Bassow ( collects chips and old calculators and runs a "virtual" CPU museum. He sent me photographs of the printed circuit board inside the Busicom calculator.

John Weinrich ( built a 4004-based tic-tac-toe game. He sent me a bunch of the technical documentation on the 4004.

My MIT Media Lab web page (

Prof. William Aspray ( u=waspray) has researched the history of the 4004 extensively and conducted first-hand interviews with its inventors. His Masatoshi Shima oral history interview offers a Japanese perspective on the 4004 development. Aspray's journal article "The Intel 4004 Microprocessor: What Constituted Invention?, published in the IEEE Annals of the History of Computing, Vol. 19, No. 3 (1997) gives a great overview of the historical context and considers whether the birth of the microprocessor was a revolutionary or evolutionary milestone in the history of technology. [Unfortunately, this seminal article is copyrighted, so I can't publish the PDF file here. You could buy it from the IEEE for US$19, or you can see if your local college or university library offers free access to the IEEE's digital archives.]