OT - help with SCO communication problem

[Brian K. White]

----- Original Message ----- 
From: <Leefp1 at aol.com>
To: <filepro-list at seaslug.org>
Sent: Saturday, July 02, 2005 8:15 PM
Subject: OT - help with SCO communication problem


> Looking for any SCO gurus to help diagnose a problem.
>
> In a sentence, the problem is I have lost serial communication from a 
> Windows
> XP Terminal running Anzio Lite to a SCO host and cannot figure out why.
>
> Environment:  SCO OS 5.0.3.  Host is Intel based SCSI box with two serial
> ports on the motherboard.  Com 1 (tty1A) is used for a dial up modem; Com 
> 2
> (tty2a) is used for the serial connection to the Windows box.  This 
> terminal at
> this site has worked for several YEARS with no maintenance and no 
> problems.
>
> Problem:  As of this past Friday morning when people at this site started
> working, the communication would not work.  Worked on Thursday; did not 
> work on
> Friday.  Two things happened in between:  electrical storm Thursday night
> (Windows box was turned off, but dial up modem connection, used for 
> internet
> access, on that box was left connected); some System admin work on the 
> Unix host,
> e.g. running fsck.
>
> The strange this is that if I disable tty2a and then reenable it; Unix 
> sends
> a getty to the windows box and the login prompt appears.  But no 
> keystrokes
> will be accepted. I am not at the site now, but I wish I would have tried
> sending a date prompt to the terminal to see if it would have showed up... 
> I suspect
> it would.  Thus, in my laymen's terms, it appears the unix host is able to
> send to the windows box but the windows box cannot send back.
>
> My first thought was that the electrical storm fried the Windows serial 
> port
> (it had only one, com 1).  So I installed a separate board with two more 
> ports
> (Com 4 and Com 5).  Same result... I could get a login to come up but 
> could
> not send keystrokes from the terminal.
>
> So...  any ideas what circumstance could cause this behavior?  By the way,
> there is a null modem in the connection between the unix box and the 
> terminal.
> In case the problem was in the wiring between the two, I physically took 
> the
> terminal to the room where the host is and connected directly from serial 
> port
> to serial port with a short cable (but of course still had to use the 
> null).
> Same result.  Could it be the null modem?  I will take a new one there 
> Tuesday
> to find out, but I doubt that is the problem.
>
> Also interesting, if I uncheck the "full duplex" option on the Anzio
> communication menu, I can at least get keystrokes to echo to the screen, 
> although it
> is gibberish and will not perform a line feed.  I have no idea what that 
> means.
>
> Any help?  Thanks much.
>
> -Lee
> ---------------------------------------------
> Lee B. Walker
> Walker & Company
> 5307 Front Royal Drive
> Cross Lanes, WV 25313
> 304-419-0013
> leefp1 at aol.com
> www.walkeronline.com

Assuming none of the things that determine the serial ports parameters on 
the sco box changed then I have no difficulty at all beleiving the serial 
port on the sco box fried.
Slap an add-in serial card in the sco box and disable the built-in in the 
bios and away you go.
Fried serial ports are perfectly common. One site I worked at last year lost 
half the ports on a 16 port equinox terminal server in one night.
There wasn't any doubt where the problem was. The smell made a very strong 
suggestion where to look, and looking (inside the case) proved it.

I didn't know there ever was such a thing as sco osr 5.0.3

Brian K. White  --  brian at aljex.com  --  http://www.aljex.com/bkw/
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