Good suggestions!  In the case where no session was found on LDEV
20, the program could open 20 as an output device file and do a write to
it.  Of course, you would want to close it right away so it would be
available to accept sessions.

>>> WirtAtmar <[log in to unmask]> 05/13/98 10:29am >>>
John Zoltak writes:

> Monitoring for a voltage change on data-out would not work if someone
>  moves the console.

The console messages aren't a necessary condition of the Keep Alive
circuit,
merely icing on the cake. A small job sending a message to Port 20's
session
every 90 seconds would be all that's necessary, regardless of whether
or not
it was the console at the moment.

I would suggest the message be "Esc A CR LF". This message would
cause the
cursor on the terminal to simply recycle in place.

What would kill the circuit would be if someone should sign on to another
session on the Port 20/console terminal. The Keep Alive job would have
to be
restarted with the new session number entered. Alternatively, with 10
minutes
more programming, the program could be made to seek out and find the
session
number of the Port 20 device automatically. The only killer would then be
that
someone would simply sign the terminal off by doing a ":BYE". But I would
suspect you'd find that out in about two minutes :-).

Wirt Atmar