**Madas 20BZS**

**Madas 20BZS**

Mechanical, electrically driven, stepped-gear calculator.

4 functions - addition, subtraction, multiplication, division.

The accumulator is at the top and can show a result to 20 places of decimals. The numbers entered can be to 10 places of decimals.

375 mm x 320 mm x 215 mm (15" x 13" x 9"), 16 Kg (35 lbs).

Made in Switzerland by H.W. Egli S.A., Zurich.

Dates from 1950s or '60s.

View underneath, with the bottom cover removed, showing the electric motor which powers this model. Hand-operated models were also available.

*The name "Madas" is derived from the initial letters of " Multiplication, Automatic Division, Addition, & Subtraction". It is a mechanical calculator,
driven by an electric motor and automatically performs the four standard functions (with a lot of whirring and clunking !).*

*These machines evolved over many years from the "Millionaire" calculator.*

* *

The history and internal workings of Madas calculators are described in an excellent article by Ray Mackay at http://www.dotpoint.com/xnumber/madas.htm.

In John Wolf's Web Museum there is an overview of Millionaire and Madas calculators, including some incredible pages showing a similar Madas calculator disassembled into its various mechanisms. It vividly illustrates the vast number of high-precision components required and the ingenuity in squeezing everything into a small space.

**Mechanical Calculators**

*Vintage Calculators *

© Text & photographs copyright Nigel Tout 2000-2015 except where noted otherwise.