"party line" for terminals?
James at jdfogg.com
Fri Mar 17 09:04:40 CST 2006
> I purchased an odd terminal display (no keyboard) from ebay
> recently and it arrived today. Its manufactured by
> Westinghouse Canada and has
> 3 ports that look like DB25 female style and 1 DB9 style
> female port that says "party line". I'll post more detail
> later, but oddly enough this terminal monitor doesn't appear
> to have a keyboard port, unless it connects to one of the
> data ports on the back.
> What is the "party line" port and what's it used for? A
> search of the cctalk archives didn't yield anything.
There are some terminal protocols that use a daisy-chained RS232. The
Burroughs/Unisys Poll Select protocol is one. It relies on the handshake
lines in standard RS232.
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