About the seminar

This lecture concerns the topic of mechanical calculation

It will focus on advanced and little-known techniques

For example the carry look ahead technique, invented by Charles Babbage was found again by Olivetti for the Summa Quanta in 1949, the continuous addition, invented by Tchebychev, was fully used in the Marchant Figurematic in 1950.

Then it explains how semi-automatic, automatic and reduced multiplication, automatic division and automatic square root extraction were implemented with cogwheels.

Some of those techniques were found in the very early electronic calculators but rapidly became obsolete.

About the speaker

Alain Guyot was an associate professor with ENSIMAG, an engineering school, where he taught and did research on computer architecture and VLSI design. He was one of the founder of the silicon foundry service CMP in 1980.

Now retired for ten years, he is a member of ACONIT, that probably owns the largest collection of computers in Europe, and ANCMECA, a federation of calculating machine collectors and museum curators.

Alain Guyot, co-author of more than one hundred publications, still loves to understand and to explain.

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