PDP-11/20, was Re: ebay question

From: ed sharpe <esharpe_at_uswest.net>
Date: Sun Feb 29 20:37:39 2004

I remember seeing leds in 1970 in the summer.... it was amazing how long
they would shine and not totally kill the battery!

Thanks Ed Sharpe archivist for SMECC

Please check our web site at
 http://www.smecc.org
to see other engineering fields, communications and computation stuff we
buy, and by all means when in Arizona drop in and see us.

address:

 coury house / smecc
5802 w palmaire ave
glendale az 85301



----- Original Message -----
From: "Ulf Andersson" <ulf.andersson_at_ipbolaget.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk_at_classiccmp.org>
Sent: Friday, February 27, 2004 8:56 AM
Subject: SV: PDP-11/20, was Re: ebay question


> >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-----
> >
> > > 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.
> >
>
> etc etc, ad infinitum...
>
>
>
Received on Sun Feb 29 2004 - 20:37:39 GMT

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