Path: utzoo!censor!geac!torsqnt!hybrid!scifi!bywater!uunet!cs.utexas.edu!ut-emx!ibmchs!auschs!awdprime!batcomp.austin.ibm.com!robin
From: robin@batcomp.austin.ibm.com (Robin D. Wilson)
Newsgroups: comp.unix.aix
Subject: Re: 6000 does not drop DTR
Message-ID: <4750@awdprime.UUCP>
Date: 11 Jan 91 15:48:52 GMT
References: <1490@msa3b.UUCP>
Sender: news@awdprime.UUCP
Organization: IBM AWD, Austin
Lines: 31

In article <1490@msa3b.UUCP> kevin@msa3b.UUCP (Kevin P. Kleinfelter) writes:
)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.

This will be fixed in 3003. 

)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.

This is by design.  (I don't know why... Maybe John Haugh can explain it.)
For the most part they intend for you to drop DTR by disabling the port.  
Normally, this will work, but the 64 port has a problem with it right now
(or prior to 3003).  If you really want "ALL" ports disabled (hence - 
pdisable -a) then you can shut off power to the 64 port's 16 port 
concentrators - then turn it back on... That should leave DTR low.

-- 
+-----------------------------------------------------------------------------+
|The views expressed herein, are the sole responsibility of the typist at hand|
+-----------------------------------------------------------------------------+
|UUCP:     robin%aixserv@uunet.uu.net                                         |
|USNail:   701 Canyon Bend Dr.                                                |
|          Pflugerville, TX  78660                                            |
|          Home: (512)251-6889      Work: (512)823-3015                       |
+-----------------------------------------------------------------------------+