Calculator Technology

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Calculator Mechanisms

Common types of Mechanical Calculator Mechanisms:

  1. Full-keyboard key-driven calculators
  2. Full-keyboard "Add-lister" calculators
  3. 10-key "Add-lister" calculators
  4. Rotary pin-wheel calculators
  5. Stepped gear calculators
  6. "Troncet" type stylus calculators
  7. Dial calculators

There are also other, less common, types of mechanical calculator.

1) Full-keyboard key-driven calculators

Examples

Comptometer

Comptometer

2) Full-keyboard "Add-lister" calculators

Examples

Burroughs Add-lister

Burroughs Add-lister

3) 10-key "Add-lister" calculators

Examples

Olivetti Summa Prima

Olivetti Summa Prima (with Sterling currency keyboard)

4) Rotary pin-wheel calculators

Examples

Original Odhner

Original Odhner

pin wheels

Close up from the right end showing the pin wheels with the number of pins raised on each wheel depending on the number set by each lever (from top to bottom 0087654321).
These pins act as gear teeth when the crank handle is turned.

5) Stepped gear calculators

Examples

Madas

Madas (driven by electric motor)

6) "Troncet" type stylus calculators

Examples

Addiator

Addiator (sterling currency version)

7) Dial calculators

Examples

Bowler Countess

Bowler Countess (Sterling currency version)

Vintage Calculators

© Text & photographs copyright Nigel Tout   2000-2017  except where noted otherwise.