27 Feb
2004
27 Feb
'04
4:56 a.m.
From the Wikipedia
http://en.wikipedia.org/wiki/Light-emitting_diode
A light-emitting diode (LED) is a semiconductor device that emits incoherent
monochromatic light when electrically biased in the forward direction. This
effect is a form of electroluminescence. The color depends on the
semiconducting
material used, and can be near-ultraviolet, visible or infrared. Nick Holonyak
Jr.
(1928 - ) developed the first practical visible-spectrum LED in 1962.
This would probably conclude the speculations on earliest date for LEDs to
appear on front panels. This has no impact on the history of DEC practise
though...
If anybody has more precise facts on commercial availability, please come
forward
and presents your facts.
/Ulf Andersson
-----It was written-----
etc etc, ad infinitum...
Remember that the 11/20 came out in 1971.
I'm not sure LEDs even
existed that long ago, and they certainly weren't common as lamp
My HP9810 calculator has LED displays and a row of 5mm LEDs along the top
of the keyboard for status indication (program/run mode, etc). Dunno the
exact date, but it's around 1972 I think.