mind as the ideal size," possibly a quip on Clive Sinclair's smoking habit. 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. Design Magazine described it as "at once a conversation piece, a rich man's plaything and a functional business machine". One Executive is on display at the Museum of Modern Art in New York City, and the futuristic design earned it the Design Council Award for Electronics in 1973. 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". Functions As well as four-function arithmetic, the Executive had the ability to compute squares, reciprocals, and multiply or divide by a fixed constant. The Executive could carry out sums to two, four or six decimal places, or use a floating decimal point. Microprocessor The calculator was powered by a Texas Instruments TMC1802NC, a metal oxide semiconductor integrated circuit with 7000 transistors. This CPU normally consumes 350 milliwatts, but by pulsing the power this requirement was reduced to 20 milliwatts. It was discovered that an early prototype continued to work if the batteries were disconnected and then reapplied quickly enough, as the capacitors in the circuit could hold a charge for up to five seconds. 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 over 65 microseconds between. The device relies on the capacitance of the chips to store information when there is no power, and 1.7 microseconds proved sufficient for the chip to carry out a single change of state of the electronics. Any calculation can be done in 1000 such changes. This had the effect of extending battery life to about 20 hours of continuous use with three small hearing aid batteries, equivalent to about four months of normal usage. Screen The screen on the Executive was a monolithic seven-segment gallium arsenide light emitting diode display, bought from a Canadian firm. The small screen reduced the power consumption and material costs, but it was revised several times in pursuit of lower power consumption,