Sinclair Executive
Encyclopedia
Clive Sinclair
Sir Clive Marles Sinclair is a British entrepreneur and inventor, most commonly known for his work in consumer electronics in the late 1970s and early 1980s....
's first venture into the pocket calculator market. The Executive was the world's first "slimline" pocket calculator. It was variously described as "a piece of personal jewelry" (New Scientist
New Scientist
New Scientist is a weekly non-peer-reviewed English-language international science magazine, which since 1996 has also run a website, covering recent developments in science and technology for a general audience. Founded in 1956, it is published by Reed Business Information Ltd, a subsidiary of...
) and "at once a conversation piece, a rich man's plaything and a functional business machine
Machine
A machine manages power to accomplish a task, examples include, a mechanical system, a computing system, an electronic system, and a molecular machine. In common usage, the meaning is that of a device having parts that perform or assist in performing any type of work...
" (Design Magazine). An example of the calculator is displayed at the Museum of Modern Art in New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
.
History
The Executive was launched in August 1972 at the price of plus VATVat
Vat or VAT may refer to:* A type of container such as a barrel, storage tank, or tub, often constructed of welded sheet stainless steel, and used for holding, storing, and processing liquids such as milk, wine, and beer...
, which at that time was about two or three times the average weekly wage.
Design
The Executive weighed only 2.5 ounces (70.9 g) and measured 5.5 × 2.25 × 0.4 inches (14 × 5.7 × 1.0 cm).The Executive was remarkably thin for its time, made possible by the first use of button-type batteries
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...
to power a calculator. To do this, Sinclair had to overcome the problem of the power hungry calculator electronics and LED
LEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....
display. It was common to pulse the power to the LED display to reduce power consumption, but Sinclair's engineers found that it was also possible to rapidly pulse the main calculator integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
(chip). This method of operation relied on the capacitance
Capacitance
In electromagnetism and electronics, capacitance is the ability of a capacitor to store energy in an electric field. Capacitance is also a measure of the amount of electric potential energy stored for a given electric potential. A common form of energy storage device is a parallel-plate capacitor...
of the devices in the chip to retain information during a calculation, and it was claimed that the power consumption of the chip was reduced from 350 milliwatts to about 20 milliwatts. Texas Instruments
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
, the manufacturer of the chip, said it had not tested them operating like this, but Sinclair said that it tested all the chips before it used them. This had the effect of extending battery life to about 20 hours of continuous use.