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Comptometer
The Comptometer was the first commercially successful key-driven mechanical calculator, patented in the United States by Dorr Felt in 1887. A key-driven calculator is extremely fast because each key adds or subtracts its value to the accumulator as soon as it is pressed and a skilled operator can enter all of the digits of a number simultaneously, using as many fingers as required, making them sometimes faster to use than electronic calculators. Consequently, in specialized applications, comptometers remained in use in limited numbers into the early 1990s, but with the exception of museum pieces, they have all now been superseded by electronic calculators and computers. Manufactured without interruption from 1887 to the mid-1970s, it was constantly improved. The mechanical versions were made faster and more reliable, then a line of electro-mechanical models was added in the 1930s. It was the first mechanical calculator to receive an all-electronic calculator engine in 1961, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comptometer Model ST Super Totalizer
The Comptometer was the first commercially successful key-driven mechanical calculator, patented in the United States by Dorr Felt in 1887. A key-driven calculator is extremely fast because each key adds or subtracts its value to the accumulator as soon as it is pressed and a skilled operator can enter all of the digits of a number simultaneously, using as many fingers as required, making them sometimes faster to use than electronic calculators. Consequently, in specialized applications, comptometers remained in use in limited numbers into the early 1990s, but with the exception of museum pieces, they have all now been superseded by electronic calculators and computers. Manufactured without interruption from 1887 to the mid-1970s, it was constantly improved. The mechanical versions were made faster and more reliable, then a line of electro-mechanical models was added in the 1930s. It was the first mechanical calculator to receive an all-electronic calculator engine in 1961, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comptometer Model A
The Comptometer was the first commercially successful key-driven mechanical calculator, patented in the United States by Dorr Felt in 1887. A key-driven calculator is extremely fast because each key adds or subtracts its value to the accumulator as soon as it is pressed and a skilled operator can enter all of the digits of a number simultaneously, using as many fingers as required, making them sometimes faster to use than electronic calculators. Consequently, in specialized applications, comptometers remained in use in limited numbers into the early 1990s, but with the exception of museum pieces, they have all now been superseded by electronic calculators and computers. Manufactured without interruption from 1887 to the mid-1970s, it was constantly improved. The mechanical versions were made faster and more reliable, then a line of electro-mechanical models was added in the 1930s. It was the first mechanical calculator to receive an all-electronic calculator engine in 1961, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sumlock ANITA Calculator
The ANITA Mark VII and ANITA Mark VIII calculators were launched simultaneously in late 1961 as the world's first all-electronic desktop calculators. Designed and built by the Bell Punch Co. in Britain, and marketed through its Sumlock Comptometer division, they used vacuum tubes and cold-cathode switching tubes in their logic circuits and nixie tubes for their numerical displays. They were the first of a series of desktop and hand-held electronic calculators that the company was to develop and sell under the ANITA name into the mid-1970s. History of ANITA calculators The acronym 'ANITA' was officially proclaimed to be derived from, variously, A New Inspiration To Arithmetic, or A New Inspiration To Accounting, though there have been rumours that this was also the name of the designer's wife. The Bell Punch Company (named after its first product, a ticket punch with a bell used by tram and bus conductors) had been producing a very successful range of key-driven mechanical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Method Of Complements
In mathematics and computing, the method of complements is a technique to encode a symmetric range of positive and negative integers in a way that they can use the same algorithm (hardware) for addition throughout the whole range. For a given number of places half of the possible representations of numbers encode the positive numbers, the other half represents their respective additive inverses. The pairs of mutually additive inverse numbers are called ''complements''. Thus subtraction of any number is implemented by adding its complement. Changing the sign of any number is encoded by generating its complement, which can be done by a very simple and efficient algorithm. This method was commonly used in mechanical calculators and is still used in modern computers. The generalized concept of the ''radix complement'' (as described below) is also valuable in number theory, such as in Midy's theorem. The ''nines' complement'' of a number given in decimal representation is formed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Calculator
A mechanical calculator, or calculating machine, is a mechanical device used to perform the basic operations of arithmetic automatically, or (historically) a simulation such as an analog computer or a slide rule. Most mechanical calculators were comparable in size to small desktop computers and have been rendered obsolete by the advent of the electronic calculator and the digital computer. Surviving notes from Wilhelm Schickard in 1623 reveal that he designed and had built the earliest of the modern attempts at mechanizing calculation. His machine was composed of two sets of technologies: first an abacus made of Napier's bones, to simplify multiplications and divisions first described six years earlier in 1617, and for the mechanical part, it had a dialed pedometer to perform additions and subtractions. A study of the surviving notes shows a machine that would have jammed after a few entries on the same dial, and that it could be damaged if a carry had to be propagated over a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorr Felt
Dorr Eugene Felt (March 18, 1862 – August 7, 1930) was an American inventor and industrialist who was known for having invented the Comptometer, an early computing device, and the Comptograph, the first printing adding machine. The ''Felt & Tarrant Manufacturing Company'' that he co-founded with Robert Tarrant on January 25, 1889 J. Turk, p. 75 (1921) remained a major player in the calculator industry until the mid-1970s. Biography Dorr E. Felt was born in Beloit, Wisconsin Felt and Allied Families, p. 12 (1921) where he grew up on the family farm and which he left at age 14 to seek employment. His father, Eugene K. Felt, was a member of the Wisconsin State Assembly. At 16, "his bent of mind, leaning towards mechanics, led him to seek work in a machine shop in Beloit where he found his first employment in the spring of 1878." At 18, he started to learn French and eventually spoke it fluently. Papers in Illinois, p.66 (1922) In early 1882, at age 20, he came to Chicago and worked ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victor Technology
Victor Technology LLC (also known as Victor Calculator) is a supplier of printing calculators, scientific calculators, financial calculators, basic calculators, and desktop accessories with headquarters in Bolingbrook, Illinois. Victor products are sold primarily throughout the United States, Canada, and Puerto Rico through independent office supply dealers. Company history Victor Adding Machine Co. was a fledgling company in 1918 when the operator of a successful chain of meat markets gave a Victor salesman $100 for what he thought would buy an adding machine. Instead, he got 10 shares of the company's stock. In an effort to protect his investment, that man – Carl Buehler – became a director of Victor in September 1918 and was elected president of the company three months later. The first Victor adding machine, Model 110, was introduced in 1919. In 1921, Carl selected his 24-year-old son, A. C., as Vice President of Operations and advised him to operate the company by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arithmometer
The arithmometer (french: arithmomètre) was the first digital mechanical calculator strong enough and reliable enough to be used daily in an office environment. This calculator could add and subtract two numbers directly and could perform long multiplications and divisions effectively by using a movable accumulator for the result. Patented in France by Thomas de Colmar in 1820 and manufactured from 1851 to 1915, it became the first commercially successful mechanical calculator.Chase G.C.: ''History of Mechanical Computing Machinery'', Vol. 2, Number 3, July 1980, page 204, IEEE Annals of the History of Computing https://archive.org/details/ChaseMechanicalComputingMachinery Its sturdy design gave it a strong reputation for reliability and accuracy and made it a key player in the move from to calculating machines that took place during the second half of the 19th century. Its production debut of 1851 launched the mechanical calculator industry which ultimately built million ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Calculator
An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics. The first solid-state electronic calculator was created in the early 1960s. Pocket-sized devices became available in the 1970s, especially after the Intel 4004, the first microprocessor, was developed by Intel for the Japanese calculator company Busicom. Modern electronic calculators vary from cheap, give-away, credit-card-sized models to sturdy desktop models with built-in printers. They became popular in the mid-1970s as the incorporation of integrated circuits reduced their size and cost. By the end of that decade, prices had dropped to the point where a basic calculator was affordable to most and they became common in schools. Computer operating systems as far back as early Unix have included interactive calculator programs such as dc and hoc, and interactive BASIC could be used to do calculations on most 1970s an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adding Machine
An adding machine is a class of mechanical calculator, usually specialized for bookkeeping calculations. In the United States, the earliest adding machines were usually built to read in dollars and cents. Adding machines were ubiquitous office equipment until they were phased out in favor of calculators in the 1970s and by personal computers beginning in about 1985. The older adding machines were rarely seen in American office settings by the year 2000. Blaise Pascal and Wilhelm Schickard were the two original inventors of the mechanical calculator in 1642. For Pascal, this was an adding machine that could perform additions and subtractions directly and multiplication and divisions by repetitions, while Schickard's machine, invented several decades earlier, was less functionally efficient but was supported by a mechanised form of multiplication tables. These two were followed by a series of inventors and inventions leading to those of Thomas de Colmar, who launched the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in genocides within the Ottoman Empire and in the 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war. Prior to 1914, the European great powers were divided between the Triple Entente (comprising France, Russia, and Britain) and the Triple Alliance (containing Germany, Austria-Hungary, and Italy). Tensions in the Balkans came to a head on 28 June 1914, following the assassination of Archduke Franz Ferdin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
