Comptometer - Wikipedia
网页The Comptometer was the first commercially successful key-driven mechanical calculator, patented in the United States by Dorr Felt in 1887.
Comptometer Explained – Everything You Need To Know
网页The comptometer was the first commercially successful key-driven mechanical calculator and a revolutionary device that transformed bookkeeping, accounting and many other business processes for nearly a century.
Comptometer Explained – Everything You Need To Know
网页2023年7月27日 · What is the comptometer? The comptometer was the first commercially successful key-driven mechanical calculator. How does a comptometer work? The computation is carried out by pressing keys. The comptometer’s keyboard is comprised of columns each presenting a place or power of ten. The lever inside the machine pulls the …
Operating a "Comptometer" - Vintage Calculators
网页"How the Comptometer works" - animated explanations of the Comptometer mechanism. "The Comptometer Super Totalizer, a mechanical calculator" - shows the basic operation of a Comptometer. "Comptometer Arithmetic" - …
How the Comptometer Works - YouTube
网页2012年1月30日 · A visual explanation of how the Comptometer, the first practical key-driven calculator, works. Comptometers were manufactured continuously from 1887 until the 1970s.
Comptometer - Vintage Calculators
网页The Comptometer. The Comptometer was invented by the American Dorr Eugene Felt and was patented in 1887. Manufactured by the Felt and Tarrant Manufacturing Company of Chicago, the Comptometer was the first truly practical and commercially successful adding machine, with the first serious manufacture and sales occurring in 1888.
Comptometer - Vintage Calculators
网页The Comptometer was the first successful key driven adding and calculating machine. "Key driven" means that just pressing the keys adds the numbers entered to the total - no other action is required - so it is very quick for adding long lists of numbers.
Comptometer, Pronounced Like Thermometer | Cooper Hewitt, …
网页2015年12月28日 · What the comptometer, patented by Dorr E. Felt in 1887, brought to the world of mechanical calculators was an interface that gave its users far more discrete control over the functionality of the machine, opening the door for …
Comptometers - Computing History
网页A Comptometer is a mechanical (or electro-mechanical) adding machine. It was the first adding device to be operated solely by the action of pressing keys arranged vertically and horizontally. Although primarily designed for adding, division, multiplication and subtraction could also be performed.
Comptometer - Jaap's Mechanical Calculators Page
网页2015年5月1日 · The table below lists all the Comptometer models, with their most prominent characteristics. Some models (such as B and C, or H and J) are very hard to distinguish except by serial number. The serial number limits are based on observed examples, so machines with numbers outside these ranges may exist.