[NCSA-discuss] SCO nfs

[Brad Oaks]

On Wed, May 9, 2012 at 1:19 AM, Joseph Mack NA3T <jmack at wm7d.net> wrote:
> I've never seen the serial card before and didn't know such things existed.
> I didn't look at it closely except to note the thick cable coming out of it
> and that there were several W95 boxes talking to it through Wyse terminal
> emulators.

They were quite common when the system you're dealing with was first
installed. :)  I installed a few and decommissioned several others.
We converted a few of our customers from dumb terminals to Windows
machines running terminal emulators.  Some customers would have us
rewire their office for ethernet and ended up putting in a hub and
taking out the multiport serial cards.  But some of the buildings were
so tough to run new cables in that the customer decided to stick with
the serial cabling that was already run to every desk.

Occasionally there would be application logic that was specific to
which serial port the user was logging in from (e.g. different menus
for different departments).  Each user of the application often did
not have a system login, but logged directly into the application
which had direct control over the serial port (as opposed to getty and
a login process having control).  This changed when we migrated them
to using telnet, and we had to modify the application a bit to key off
of the login or group information of the system accounts instead of
from the serial port number (which was a proxy for knowing which desk
the terminal was on).

You should be able to tell by looking over a user's shoulder whether
it is a system login or if they are immediately in the application
(including authenticating with the app with a username and password).
The prompt is a good clue.

> SCO has a VM appliance. I assume this serial card is standard in SCO, so the
> VM appliance must hangle it. Certainly when creating the new machine I'll
> have to build a duplicate as an intermediate stage. Presumably these cards
> are available somewhere still

The serial cards were optional addons, and the ones that I remember
needed drivers from the card manufacturer. They could make up a
significant portion of the cost of a server, too.  DigiBoard is the
product line I remember using most, but there were others.  The
company Digi is still around and making serial cards.
http://www.digi.com/products/serialcards/