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From: gandrews@netcom.COM (Greg Andrews)
Newsgroups: comp.unix.xenix.sco
Subject: Re: Modem problem with Xenix 2.3.3
Keywords: modem problem, sio interface
Message-ID: <1991Mar24.200808.4680@netcom.COM>
Date: 24 Mar 91 20:08:08 GMT
References: <5025@ns-mx.uiowa.edu>
Distribution: usa
Organization: Netcom - Online Communication Services  UNIX System {408 241-9760 guest}
Lines: 30

In article <5025@ns-mx.uiowa.edu> dhmadsen@icaen.uiowa.edu (Donald H Madsen) writes:
>I am using Xenix386 2.3.3 and VP/ix 1.2 and after much searching have
>discovered that at random times DCD goes slowly low and makes it
>impossible to continue communication.
>
> [some stuff deleted]
>
>It seems likely that the problem is withing the serial driver.  
>
>The symtoms include line 8 (DCD) suddenly going low and line 20 RTS staying
>high.  It happens with a 2400 Baud modem and with a 9600 Baud modem.
>

I wonder how an RS232 signal goes "slowly" low??

DCD is controlled by the modem, not the computer.  The modem should
be configured to have DCD on while it has a connection, and turn it
off when the connection is broken.

It sounds like you're simply losing the connection through the phone
line.  Not something I would blame the serial driver for, unless it
is turning DTR off for a moment.

(By the way, pin 20 is DTR, not RTS.  RTS is pin 4.)

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|  Greg Andrews   |       UUCP: {apple,amdahl,claris}!netcom!gandrews    |
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