Синаир Экзекьютив: Әлемдегі алғашқы кішкентай калькулятор

Pocket calculator

The Sinclair Executive was the world's first "slimline" pocket calculator, and the first to be produced by Clive Sinclair's company Sinclair Radionics. Introduced in 1972, the calculator was produced in at least two versions with different keyboard markings; a variant called the Sinclair Executive Memory was introduced in 1973. Its small size was made possible by pulsing current to the Texas Instruments TMS1802 "calculator on a chip" integrated circuit, reducing the power consumption more than tenfold. The Executive was highly successful, making of profit for Sinclair and winning a Design Council Award for Electronics.

The Executive was launched in September 1972 at the price of plus VAT, equivalent to £ in when adjusted for inflation. This was around half the price of comparable calculators, but still twice the average weekly wage. It was the first pocket calculator, and the first to be mass produced, and its introduction to the market coincided with a number of other companies entering the calculator market. Clive Sinclair, reckoning that the market for "executive toys" was not especially sensitive to price, ordered components for 100,000 calculators. The parts, consisting of the TMS1802 chip, 22 transistors, 50 resistors and 17 capacitors, cost close to , compared with a sale price of close to
A Sinclair Executive purchased by a Russian diplomat exploded in his breast pocket, allegedly leading to an official Soviet investigation. It was found that it had been left on by accident, leading to a current drain on the batteries that overheated them until they burst.

It was significantly smaller than any of its competitors, and the first calculator that could easily be carried in a pocket. The Executive weighed and measured The case, designed by Iain Sinclair, was made of black injection moulded polycarbonate and required flexible glue to hold the two halves together. It was the first calculator designed for aesthetic appeal, and New Scientist described it as "not so much a professional calculator more a piece of personal jewellery". The Executive could carry out sums to two, four, or six decimal places, or use a floating decimal point.

The calculator was powered by a Texas Instruments TMC1802NC, a metal oxide semiconductor integrated circuit with 7000 transistors. Power is supplied to the chip in 1.7 microsecond pulses as determined by the storage time of a control transistor. An oscillator clock operating at 200 kilohertz during calculations and dropping to 15 kilohertz between each operation means shut off time ranges from 3.3 microseconds during calculations to more than 65 microseconds between. The small screen reduced the power consumption and material costs, There were at least three versions, including the black and white Type 1, and the Type 2 with a gold keyboard.