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From: kevin@msa3b.UUCP (Kevin P. Kleinfelter)
Newsgroups: comp.unix.aix
Subject: 6000 does not drop DTR
Message-ID: <1490@msa3b.UUCP>
Date: 10 Jan 91 14:05:23 GMT
Organization: Dun and Bradstreet Software, Inc., Atlanta, GA
Lines: 24

On our 6000, DTR does not seem to behave properly on the 64-port serial
card.  When booting AIX, DTR is low until the ports are initialized --
this I believe to be correct.  However, when I "pdisable -a" DTR
remains high on the ports.  On my other machines (including
SYS V and AIX 1.2) when no process has a port open, DTR is low.

Also, both ioctl and stty are unable to set the baud rate to 0 to
drop DTR unless CD is high.  In other words, if I login via port n,
and I "stty 0" it WILL drop DTR; if I login via port x, and
"stty 0 < /dev/ttyn" and CD is not high on port n, I get an
error message about an invalid parameter.

I have not tested this on the motherboard ports; this behavior is observed
on the 64-port adapter with 32 modems attached. 

I believe that this behavior is incorrect.  Has anyone else observed
similar behavior? Could it be something I am doing or is this YAASPP
(Yet Another Aix Serial Port Problem).

-- 
Kevin Kleinfelter @ Dun and Bradstreet Software, Inc (404) 239-2347
{emory,gatech}!nanovx!msa3b!kevin

Soon to become {emory,gatech}!nanovx!dbses0!kevin  (But not yet!)