Comptometer
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Article
24 sectionsContents
- History
- Origins
- The first comptometers
- Comptometer and comptograph
- Competition
- Companies and trademarks
- Felt & Tarrant Manufacturing Company
- Comptograph Company
- Comptometer Corporation
- Bell Punch Company – Sumlock Comptometer Ltd
- Victor Comptometer Corporation
- Development
- Wooden boxes
- Model A
- Model B, C, D
- Model E
- Model F
- Model H, J, ST
- Model K
- Model M, WM
- Post World War II models
- See also
- References
- External links
thumb|upright=1.2|Model ST (1930s) thumb|upright=1.2|Prototype of the first all-electronic desktop calculator marketed by of the United Kingdom|UK
The comptometer was the first commercially successful key-driven mechanical calculator, patented in the United States by Dorr Felt in 1887.