The Sharp EL-805

1973 · Liquid Crystal Pocket Calculator · Work 942 of 1,871

A pocket calculator on the fold-down table of a high-speed train near Osaka in early summer, an upright flat case twelve centimetres tall with a brushed silver front and a black edge, at its top a raised plain black panel with a small hinged lid swung open, beneath it a narrow window with a pale silvery shimmer, a small round ridged button, below rows of rounded square black keys and one red key, every key plain smooth and unmarked, a black cord loop from a metal eyelet wound around two fingers of a hand in a grey suit sleeve, a lidded cup of green tea, blurred green rice fields through the window.

What it was used for
Sharp brought out the EL-805 in 1973. By the company's own account it was a COS-type unit: liquid crystal display, CMOS-LSI circuitry and wiring all accommodated on a single glass panel. From that followed its consumption. Sharp gives the EL-805 as using 1/9,000th of the power of its first calculator model and as running 100 hours on 1 AA-size battery. Against that same first model the company gives 1/12th the thickness, 1/125th the weight, 1/250th the number of parts and 1/20th the cost.
What was new
Sharp calls the EL-805's display the world's first practical LCD unit, not the first LCD calculator as such; the company's LCD research had begun in 1970. The Computer History Museum puts it differently: the first pocket calculator with an easy-to-read liquid crystal display instead of red LEDs. Sharp itself gives the reason for the search: fluorescent and LED displays consumed a lot of electricity, so calculators needed bulky batteries.

What the sources leave open: Sharp's figures are ratios against its own first model, not absolute values; the company history gives no absolute weight, thickness or price for the EL-805. Neither source names the type of liquid crystal cell.

Connections

Every connection names its kind. “Forerunner” on its own would be a claim.

  1. Follows fromThe Compet1964The IEEE Milestone honours one Sharp project team that built successive families of calculators from 1964 on: the all-electronic Compet CS-10A in 1964 and, in 1973, the Compet EL-805 with CMOS-LSI and a liquid-crystal display on a single glass panel. Sharp itself calls the EL-805 a twelfth as thick as its own first calculator.Source: Milestones: Pioneering Work on Electronic Calculators, 1964-1973 (IEEE, ETHW) · Sharp Corporate History 1973-1975: world's first practical LCD calculator

Further reading