24 Oct
2004
24 Oct
'04
9:35 a.m.
Jules Richardson wrote:
Does anyone know when blue LEDs first became
commercially available?
I saw a blue LED waaay back in 1984, fitted to the disk controller
for a Newbrain. My friend got hold of one, somehow and fitted it
as a "power-on" LED in an early example of "case-modding"! He told
me that the blue LED was intended as a reference in spectroscopy.
It certainly formed a very narrow beam of light, instead of having
a diffuse "lens" as ordinary red LEDs do. It made a spot of light
on the opposite wall of the Uni halls-of-residence room when we
turned the lights out!
--
John Honniball
coredump(a)gifford.co.uk