Xref: utzoo comp.dcom.modems:2604 comp.sys.att:4416
Path: utzoo!utgpu!water!watmath!clyde!att!westmark!dave
From: dave@westmark.UUCP (Dave Levenson)
Newsgroups: comp.dcom.modems,comp.sys.att
Subject: Re: MORE 6386 UUCP WOES ...
Keywords: cu, Hayes Modem
Message-ID: <411@westmark.UUCP>
Date: 6 Oct 88 02:28:46 GMT
References: <319@argon.UUCP> <2096@cuuxb.ATT.COM>
Organization: Westmark, Inc., Warren, NJ, USA
Lines: 31

In article <2096@cuuxb.ATT.COM>, mmengel@cuuxb.ATT.COM (Marc W. Mengel) writes:
> In article <319@argon.UUCP> daveb@argon.UUCP (Dave Berk) writes:
> > [ Woes of using a Hayes compatable modem on a Unix box ]
> >Can anyone out there shed any light on this problem ?  
> 
> Well, it's pretty simple, actually; the problem is that your "Hayes
> compatable" modem doesn't lower CD (Carrier detect) when there is
> no carrier.  Real Hayes modems can be configured to behave this way,
> and most non-hayes modems *always* act this way.  If you set up
> your modem this way, you just need to set "HUPCL" in the /etc/gettydefs
> entries used by your modem and *not* set "CLOCAL", and you will
> be just fine.  If your modem can't be taught to drop CD, then there
> is no way in the world for Unix to magically determine that the
> phone line was disconnected.

This is, indeed,  the correct way to configure UUCP to work with a
Hayes-Compatible modem.  But it only works if the tty driver
correctly implements the CLOCAL and HUPCL ioctl modes.  The tty
driver supplied by AT&T with the UNIX SVR2 Rel 2.1 for the 6300PLUS
did not. They corrected this in the Rel 2.5 of the same product.

They then released SVR3 for the 6386, with the same problem -- the
HUPCL and CLOCAL options to /dev/tty are ignored.  Rumor has it that
this is being corrected in Rel 3.2 of this product.  Can anybody
confirm or deny this rumor?

-- 
Dave Levenson
Westmark, Inc.		The Man in the Mooney
Warren, NJ USA
{rutgers | att}!westmark!dave