Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!rutgers!ames!ucbcad!ucbvax!HDETUD53.BITNET!BART
From: BART@HDETUD53.BITNET (Bart Zorn)
Newsgroups: mod.computers.vax
Subject: Ultrix and parity
Message-ID: <8703172112.AA19501@ucbvax.Berkeley.EDU>
Date: Tue, 17-Mar-87 04:52:00 EST
Article-I.D.: ucbvax.8703172112.AA19501
Posted: Tue Mar 17 04:52:00 1987
Date-Received: Thu, 19-Mar-87 01:32:42 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: world
Organization: The ARPA Internet
Lines: 26
Approved: info-vax@sri-kl.arpa

Subject:        Ultrix and parity settings for terminals

I am currently involved in implementing a 600 port Ungerman Bass network
and doing so, believe it or not, I sometimes find my self being confronted
with a Unix system. BSD 4.2 or Gould's UTX/32 and now even ULTRIX-32.

I was very surprised to see that Digital's own ULTRIX doesn't know about the
existence of VT200 and equivalents, at least when such a terminal behaves
like one. Ultrix's login prompts with characters which have some sort of
parity set and that results in a lot of multinational characters on my
screen.

This experience leads to my question:
Has anybody ever heard of equipment and/or software which uses parity bits
whith asynchronous communication techniques in a useful way?
I know of terminals that display some error symbol when a parity error
is detected, but I have never seen anything which does a retransmit or
something like that.

If there is no such equipment and software, can anybody tell me why parity
is still being used?


Bart Zorn               (BART@HDETUD53.BITNET)
Delft University of Technology
Faculty of Electrical Engineering