An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics.
The ZX Spectrum is an 8-bit home computer developed and marketed by Sinclair Research. Considered one of the most influential computers ever made, it is also one of the best-selling British computers ever, with over five million units sold. It was released in the United Kingdom on 23 April 1982, and around the world in the following years, most notably in Europe, the United States, and Eastern Bloc countries.
The ZX81 is a home computer that was produced by Sinclair Research and manufactured in Dundee, Scotland, by Timex Corporation. It was launched in the United Kingdom in March 1981 as the successor to Sinclair's ZX80 and designed to be a low-cost introduction to home computing for the general public. It was hugely successful; more than 1.5 million units were sold. In the United States it was initially sold as the ZX-81 under licence by Timex. Timex later produced its own versions of the ZX81: the Timex Sinclair 1000 and Timex Sinclair 1500. Unauthorized ZX81 clones were produced in several countries.
Sir Clive Marles Sinclair was an English entrepreneur and inventor, best known for being a pioneer in the computing industry and also as the founder of several companies that developed consumer electronics in the 1970s and early 1980s.
The Sinclair C5 is a small one-person battery electric recumbent tricycle, technically an "electrically assisted pedal cycle". It was the culmination of Sir Clive Sinclair's long-running interest in electric vehicles. Although widely described as an "electric car", Sinclair characterised it as a "vehicle, not a car".
The Sinclair Scientific was a 12-function, pocket-sized scientific calculator introduced in 1974, dramatically undercutting in price other calculators available at the time. The Sinclair Scientific Programmable, released a year later, was advertised as the first budget programmable calculator.
Sinclair Radionics Ltd was a company founded by Sir Clive Sinclair in Cambridge, England which developed hi-fi products, radios, calculators and scientific instruments.
Christopher Curry is a British businessman and the co-founder of Acorn Computers, with Hermann Hauser and Andy Hopper. He became a millionaire as a result of Acorn's success.
Sinclair Research Ltd is a British consumer electronics company founded by Clive Sinclair in Cambridge in the 1970s. In 1980, the company entered the home computer market with the ZX80 at £99.95, at that time the cheapest personal computer for sale in the United Kingdom. A year later, the ZX81 became available through retailers, introducing home computing to a generation, with more that 1.5 million sold. In 1982 the ZX Spectrum was released, becoming the UK's best selling computer, and competing aggressively against Commodore and Amstrad.
Nigel Searle is the former managing director of Sinclair Research Ltd, and one of the company's longest-serving employees. He joined Sinclair Radionics in 1973, and for most of the 1970s, Searle worked for Sinclair in the United States to promote the company's calculators and other products. In 1977, with Sinclair in financial trouble, Searle left the company. He rejoined in 1979 when Sir Clive Sinclair formed Science of Cambridge and continued to work from the US, successfully promoting the ZX80 and ZX81 personal computers. In spring 1982, he moved back to the United Kingdom as Sinclair's managing director, a post he retained until 1986 when Amstrad took over the company's computer business.
The Sinclair Sovereign was a high-end calculator introduced by Clive Sinclair's company Sinclair Radionics in 1976. It was an attempt to escape from the unprofitable low end of the market, and one of the last calculators Sinclair produced. Made with a case of pressed steel that a variety of finishes, it cost between £30 and £60 at a time when other calculators could be purchased for under £5. A number of factors meant that the Sovereign was not a commercial success, including the cost, high import levies on components, competition from cheaper calculators manufactured abroad, and the development of more power-efficient designs using liquid-crystal displays. Though it came with a five-year guarantee, issues such as short battery life limited its usefulness. The company moved on to producing computers soon afterwards.
Sinclair Oxford was a range of low-cost scientific calculators manufactured and sold by Sinclair Radionics in England from 1975 until 1976.
The MK14 was a computer kit sold by Science of Cambridge of the United Kingdom, first introduced in 1977 for £39.95. The price was very low for a complete computer system at the time, and Science of Cambridge eventually sold over fifteen thousand kits.
The Sinclair Cambridge was a pocket-sized calculator introduced in August 1973 by Sinclair Radionics. It was available both in kit form to be assembled by the purchaser, or assembled prior to purchase. The range ultimately comprised seven models, the original "four-function" Cambridge – which carried out the four basic mathematical functions of addition, subtraction, multiplication, and division – being followed by the Cambridge Scientific, Cambridge Memory, two versions of Cambridge Memory %, Cambridge Scientific Programmable and Cambridge Universal.
The Sharp EL-8, also known as the ELSI-8, was one of the earliest mass-produced hand-held electronic calculators and the first hand-held calculator to be made by Sharp. Introduced around the start of 1971, it was based on Sharp's preceding QT-8D and QT-8B compact desktop calculators and used the same logic circuits, but it was redesigned to fit in a much smaller case.
A transistor is a semiconductor device with at least three terminals for connection to an electric circuit. In the common case, the third terminal controls the flow of current between the other two terminals. This can be used for amplification, as in the case of a radio receiver, or for rapid switching, as in the case of digital circuits. The transistor replaced the vacuum-tube triode, also called a (thermionic) valve, which was much larger in size and used significantly more power to operate. The first transistor was successfully demonstrated on December 23, 1947, at Bell Laboratories in Murray Hill, New Jersey. Bell Labs was the research arm of American Telephone and Telegraph (AT&T). The three individuals credited with the invention of the transistor were William Shockley, John Bardeen and Walter Brattain. The introduction of the transistor is often considered one of the most important inventions in history.
The Sinclair President is a calculator released by Sinclair Radionics in early 1978. There were two models, the President and the President Scientific. They were among the last calculators produced by Sinclair, and their large size was in contrast to the smaller, earlier models, like the Sinclair Executive, which made the company famous. The President models were related to the Sporting Life SETTLER, a calculator designed specifically for betting shops.
The Sharp QT-8D Micro Compet, a small electronic desktop calculator, was the first mass-produced calculator to have its logic circuitry entirely implemented with LSI integrated circuits (ICs) based on MOS (metal-oxide-semiconductor) technology. When it was introduced in late 1969, it was one of the smallest electronic calculators ever produced commercially. Previous electronic calculators had been about the size of a typewriter and had logic circuits built from numerous discrete transistors and diodes or small- to medium-scale ICs. The QT-8D's logic circuits were packed into just four LSI ICs.
The Sharp QT-8B Micro Compet, a portable electronic desktop calculator, was the first mass-produced calculator to be battery-powered. Introduced in mid-1970, it was based on its immediate predecessor, the QT-8D introduced in late 1969, but it replaced the QT-8D's integrated power supply with a rechargeable battery pack. It has the same calculating integrated circuits as the QT-8D and is of similar appearance and dimensions; the power supply is the only major difference.
Tadashi Sasaki was a Japanese engineer who was influential in founding Busicom, driving the development of the Intel 4004 microprocessor, and later driving Sharp into the LCD calculator market.
