On 2012 Apr 10, at 6:28 PM, Richard wrote:
In article <A1DA0710-CC13-4E6A-94B1-1EFE4F6891DC at
cs.ubc.ca>,
Brent Hilpert <hilpert at cs.ubc.ca> writes:
There is a standalone (integrated colour monitor)
Telidon terminal
(ca. 1980) in the back store of the radio museum here, likely in
danger of being dumpstered.
I'd be willing to rescue that if they're just gonna dumpster it.
In theory, some other Canadian museum/org would hold onto it as a bit
of national technology history .. but I can't say that is likely.
I'll keep you in mind for a destination.
Even without the keyboard it should be useable as a display terminal
to show what a teletext protocol and display were like. I should try
finding the teletext/Telidon protocol and see if I can feed it
something to display.
It's
missing the detached keyboard unfortunately, I think it was a
small-pin-count connector (perhaps RJ-something) so it should be some
serial-style interface.
There was also a tricky way of doing the keyswitch scanning using a
small number of wires, eliminating the need for a microprocessor in
the keyboard. This technique was used on the HP 2392A terminal as
described in "A Reliable, Low-Cost Keyboard Interface" on pg. 7 of
<http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1985-04.pdf>
This uses a 5-wire interface: power, ground, increment, reset and key
state. It's pretty slick.