Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!cmcl2!panix!alexis
From: alexis@panix.uucp (Alexis Rosen)
Newsgroups: comp.dcom.modems
Subject: Big problems with modems that aren't grounded. What to do?
Message-ID: <1990Dec4.023427.25652@panix.uucp>
Date: 4 Dec 90 02:34:27 GMT
Organization: PANIX - Public Access Unix Systems of NY
Lines: 23

I posted a query here a month or so ago, complaining about some very strange
problems with a bunch of 2400bps modems connected to my unix box.

While I'm not sure of this, it now seems likely that the problems are the
result of poor grounding. I think this because the Telebit performs flawlessly,
and the US Robotics nearly so. They both have three-prong (grounded) plugs on
their transformers. The other three modems (a Smart One, a Prometheus, and a
Maxxum) lack grounding, and they frequently die (although the Smart One is
rather less susceptible).

The problem is that the modems and the computer frequently fail to recognize
that DCD and/or DTR control lines have been raised. Thus, the modems may not
answer, and if they do, the getty may not complete the open.

Is there anything I can do to deal with this situation? If not, I suppose I'll
need to get new modems. Which cheap modems have a ground connector? The ones
I know of, which are generally trouble free, don't have these.

Thanks,
---
Alexis Rosen
Owner/Sysadmin, PANIX Public Access Unix, NY
{cmcl2,apple}!panix!alexis