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Carver cm 1090 service manual

Computing hardware is a platform for information processing. Carver cm 1090 service manual from four early computers, 1962. From left to right: ENIAC board, EDVAC board, ORDVAC board, and BRLESC-I board, showing the trend toward miniaturization. The history of computing hardware covers the developments from early simple devices to aid calculation to modern day computers.

Before the 20th century, most calculations were done by humans. Early mechanical tools to help humans with digital calculations, such as the abacus, were called “calculating machines”, called by proprietary names, or referred to as calculators. The first aids to computation were purely mechanical devices which required the operator to set up the initial values of an elementary arithmetic operation, then manipulate the device to obtain the result. Later, computers represented numbers in a continuous form, for instance distance along a scale, rotation of a shaft, or a voltage. Numbers could also be represented in the form of digits, automatically manipulated by a mechanical mechanism.

The Ishango bone is thought to be a Paleolithic tally stick. Devices have been used to aid computation for thousands of years, mostly using one-to-one correspondence with fingers. The earliest counting device was probably a form of tally stick. Several analog computers were constructed in ancient and medieval times to perform astronomical calculations. Scottish mathematician and physicist John Napier discovered that the multiplication and division of numbers could be performed by the addition and subtraction, respectively, of the logarithms of those numbers.

While producing the first logarithmic tables, Napier needed to perform many tedious multiplications. Since real numbers can be represented as distances or intervals on a line, the slide rule was invented in the 1620s, shortly after Napier’s work, to allow multiplication and division operations to be carried out significantly faster than was previously possible. Wilhelm Schickard, a German polymath, designed a calculating machine in 1623 which combined a mechanised form of Napier’s rods with the world’s first mechanical adding machine built into the base. Because it made use of a single-tooth gear there were circumstances in which its carry mechanism would jam. View through the back of Pascal’s calculator. Pascal invented his machine in 1642. In 1642, while still a teenager, Blaise Pascal started some pioneering work on calculating machines and after three years of effort and 50 prototypes he invented a mechanical calculator.

Gottfried Wilhelm von Leibniz invented the stepped reckoner and his famous stepped drum mechanism around 1672. He attempted to create a machine that could be used not only for addition and subtraction but would utilise a moveable carriage to enable long multiplication and division. Around 1820, Charles Xavier Thomas de Colmar created what would over the rest of the century become the first successful, mass-produced mechanical calculator, the Thomas Arithmometer. It could be used to add and subtract, and with a moveable carriage the operator could also multiply, and divide by a process of long multiplication and long division. In 1804, Joseph-Marie Jacquard developed a loom in which the pattern being woven was controlled by a paper tape constructed from punched cards.

The paper tape could be changed without changing the mechanical design of the loom. This was a landmark achievement in programmability. In the late 1880s, the American Herman Hollerith invented data storage on punched cards that could then be read by a machine. By 1920, electromechanical tabulating machines could add, subtract and print accumulated totals. Machine functions were directed by inserting dozens of wire jumpers into removable control panels.

Leslie Comrie’s articles on punched card methods and W. The Curta calculator could also do multiplication and division. By the 20th century, earlier mechanical calculators, cash registers, accounting machines, and so on were redesigned to use electric motors, with gear position as the representation for the state of a variable. The word “computer” was a job title assigned to primarily women who used these calculators to perform mathematical calculations. Companies like Friden, Marchant Calculator and Monroe made desktop mechanical calculators from the 1930s that could add, subtract, multiply and divide. The world’s first all-electronic desktop calculator was the British Bell Punch ANITA, released in 1961.

Charles Babbage, an English mechanical engineer and polymath, originated the concept of a programmable computer. The programming language to be employed by users was akin to modern day assembly languages. Loops and conditional branching were possible, and so the language as conceived would have been Turing-complete as later defined by Alan Turing. The machine was about a century ahead of its time. However, the project was slowed by various problems including disputes with the chief machinist building parts for it.

All the parts for his machine had to be made by hand—this was a major problem for a machine with thousands of parts. Eventually, the project was dissolved with the decision of the British Government to cease funding. Following Babbage, although unaware of his earlier work, was Percy Ludgate, an accountant from Dublin, Ireland. He independently designed a programmable mechanical computer, which he described in a work that was published in 1909. In the first half of the 20th century, analog computers were considered by many to be the future of computing. The first modern analog computer was a tide-predicting machine, invented by Sir William Thomson, later Lord Kelvin, in 1872. It used a system of pulleys and wires to automatically calculate predicted tide levels for a set period at a particular location and was of great utility to navigation in shallow waters.