In Tokyo in 1964 I bought a Soroban with Kojima’s book "The Japanese Abacus: Its Use and Theory". An event that sparked my interest in abaci ... and in computers.

After getting my M.Eng.(Elect.) at Cornell, my 30 year career included working on the design and construction of nuclear power plants, missile systems software engineering, and industrial and engineering computer systems sales and systems engineering.

Deciding to become a high school math teacher at the end of 2000, I took a History of Math course as part of my M.Ed. Program at UMassLowell. I was struck by how easy it would be to use ancient Roman, Greek, Egyptian, and Babylonian numerals to record abaci calculation results. Prof. Gonzalez said, "Yes, but how would you do multiplication and division?"

So as a hobby, I've worked the last 10 years to (re)discover the schematics and rules of the the Ancients used to do their accounting and engineering to support and empower the greatest empires in human history.

I hope you find Ancient Computers interesting and useful,

Steve Stephenson, M.Eng.(Elect.), M.Ed.
Math Teacher (precalculus and calculus)
Lowell High School, MA
July 15, 2010 (Retired 6/30/2013)

P.S.: Before you edit Ancient Computers, please be sure you read and understand the whole article and the Works Cited, and have watched and understand all of Stephenson's videos.

P.P.S.: Also available as of 7/15/2013 are paperback and eBook versions of Ancient Computers with essentially the same content (see Links). Because it's much easier to modify, updates will first show up on