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From: john@uw-nsr.UUCP
Newsgroups: net.dcom
Subject: Racal-Vadic and Data General
Message-ID: <505@uw-nsr.UUCP>
Date: Sat, 25-Oct-86 15:15:19 EST
Article-I.D.: uw-nsr.505
Posted: Sat Oct 25 15:15:19 1986
Date-Received: Sun, 26-Oct-86 09:52:42 EST
Reply-To: john@uw-nsr.UUCP (John Sambrook 5-7433)
Distribution: na
Organization: UW-Bioengineering, Seattle, WA
Lines: 44
Keywords: Why did my Racal-Vadic modems and couplers quit working?

After converting to DG/UX revision 3.00 people dialing in to our 
system with Racal-Vadic equipment get so many errors that they can't 
use the system.

We have a Data General MV/10000 running DG/UX 3.00.  Of the 40
tty lines available eight have modem control and are attached to 
various modems, line drivers and multiplexors.  Five of the eight
lines are connected to Micom 300 / 1200 baud modems set up for auto-
answer.  They are not set up for autobauding.  In the past they have
always worked flawlessly.

Under the previous revision of DG/UX (2.02) all of our users were able
to dial in and use the system.  However, one of the major changes in 
revision 3.00 of DG/UX was `totally rewritten' IAC code.  This is code
that it downloaded at boot time to the Intelligent Asynchronous 
Controllers (IAC's).  

Under the new revision people dialing in with equipment manufactured
by Racal-Vadic get so many errors that the can't use the system at all.
Often what they type is not echoed but seems to be received; other times
the echoed character is wrong although the received character is correct.
To date the problem seems to be confined to Racal-Vadic VA3434 1200 baud
acoustic couplers and a Racal Maxwell 1200 / 2400 baud modem being used 
at 1200 baud.  I am sorry but I don't have a model number on the latter.

I am writing this from home over a Hayes Smartmodem.  It works fine and
any errors can be attributed to operator error :-)

I seem to recall some folklore about Racal-Vadic equipment being somehow
different from other types of equipment.  However, when everything is 
working I don't save such information.  Now I am wishing that I had.

So, if anyone could shed some light on this situation I would certainly
appreciate it.  Of course I suspect that the new IAC code is the problem.
However, I am certainly no TC expert and would welcome suggestions about
possible problem areas.

Thanks,

John

-- 
John Sambrook                           Work: (206) 545-7433
University of Washington WD-12          Home: (206) 487-0180
Seattle, Washington  98195              UUCP: uw-beaver!uw-nsr!john