Panaplex display history
ard at p850ug1.demon.co.uk
Mon Jun 1 12:42:26 CDT 2015
> > Thinking about it, I find it surprising that on later disk drives -- RL's, RK07s,
> > R80s etc, they used bulbs and not LEDs. By that date LEDs were easily available and
> > reliable.
> I think it was just harder to replace the construction where you had
> push buttons with lamps. Those are not bi-pins.
True. But there was no reason to introduce illuminated buttons, was there?
The older drives had separate indicators. So DEC made a change which
essentially forced them to use less reliable, higher current, indicators.
IIRC the R80 (and probably others) has a lamp test facility so that when
you get a FAULT you can be sure that the bulbs are all working and that
the indication is therefore genuine. LEDs probably wouldn't have needed
I seem to recall that CDC at about that time had a pushbutton with a
rectangular LED on the surface of the button. That seemed quite a neat
device. I am sure DEC could have come up with something.
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