30 Aug
2004
30 Aug
'04
9:15 a.m.
>>>> "Brent" == Brent Hilpert
<hilpert(a)cs.ubc.ca> writes:
Brent> Speaking of various keyboards: some time ago I received a bare
Brent> (no machine, no case, no ID) keyboard utilising
Brent> magnetically-activated reed relays for the key contacts. Reed
Brent> relays were commonly used for calculator keyboards in the
Brent> late-60s/early 70s and it probably dates from this era, but
Brent> this is the only occasion I have seen reed relays used in an
Brent> alphabetic keyboard.
PLATO 3 used reed switches, and I believe PLATO IV did likewise.
Liquid proofing is clearly a good reason: those systems were intended
for use by students (of all ages) and were certainly likely to have
beverages spilled on them. Because of how they were built, a good
scrub under hot water would fix them right up.
paul