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Date:      Mon, 3 Apr 1995 09:37:39 -0500 (CDT)
From:      Guy Helmer <ghelmer@alpha.dsu.edu>
To:        Shane Anderson <shane@et.pronex.com>
Cc:        questions@FreeBSD.org
Subject:   Re: modems
Message-ID:  <Pine.OSF.3.91.950403092106.29025E-100000@alpha.dsu.edu>
In-Reply-To: <329@et.pronex.com>

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On Sat, 1 Apr 1995, Shane Anderson wrote:

> Well, I have taken the kind comments and suggestions and continued
> to try to get a dial in connection, but to no avail.  Neither my
> microcomm 28.8 nor my viva 14.4 (19200) will work.  They both
> answer the phone fine and establish a connection, but high-order
> garbage is still the order of the day.

A problem I've seen is not locking the dialing modem at the terminal's
speed; it appears when a high-speed connection is made, the modem's serial
port speed seems indeterminate depending on the type of connection (in
particular, I've seen this problem with a 28.8 modem to 14.4 modem and a
14.4 to 28.8).  On the USR Sportsters I'm familiar with, "AT&B1" locks the
modem's serial port at the data rate used to issue the command, and it has
solved the problems I've seen here... 

> This is most frustrating.  I have been in telecommunications in
> the DOS world for over ten years and I feel like a total moron.  It
> just can't be THAT hard.

Dittos!

> I have gotten it to connect via an old 2400 bps viva at 2400.  THAT
> was straightforward.  However, I don't see using that modem on
> this machine.
> 
> As for the hs modems, I am not sure HOW to lock them at 38400 or
> 19200.  Anyone have an it string that will do this?   The HS light
> does not light, and every time a connection is made, the modem
> apparently reverts to 9600bps, notwithstanding all configs and a
> stty -f /dev/ttyd0 38400 command.  Furthermore, setting my term
> to 9600 does not make the garbage "go away."  Though I thought it
> might be the result codes screwing me up, setting the X[n]
> register to 0 does not help.  Any and all specific setup, init
> info and help here would be appreciated. 

The command string most likely depends on your brand of modems, but as I
mentioned above "AT&B1" locks our USR Sportsters at the current data 
rate.  "AT&B2&W" sets our Sportsters (on the dialup side) to use a locked 
speed for error-corrected connections (V.42 or MNP), and vary the port 
speed for other connections.  We also have "AT&N0" set on our dialup 
Sportsters, which allows connections at any of the supported connection 
rates (300 bps to 14.4Kbps).

I would hope that you could find the modem port's speed (by adjusting your
terminal program's port speed, perhaps to 19.2Kb and 38.4Kb if 9600
doesn't work) and at least verify that the two modems are correctly 
communicating...

> I guess the question becomes then:  what high speed modem should I
> purchase that WILL work, and where do I get it (if not an off-the
> shelf modem)? If time is money, I have already spent the money for
> the new modem... easily five time over. I might as well be done
> with it. 

This is not a plug, but I have had success with USR Sportster 14,400 
external modems.  I haven't yet tried the Sportster 28,800 external 
modems, though...

> shane
> -----
> Shane G. Anderson
> Internet:  shane@et.pronex.com
>            shane@et.expressnet.org

Guy Helmer, Dakota State University Computing Services - ghelmer@alpha.dsu.edu




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