17 Mar
2006
17 Mar
'06
7:04 a.m.
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.