[comp.os.vms] Debugging spoolers sending DEBUG output to DECSERVERS.

MRL@PFC-VAX.MIT.EDU (06/28/88)

I am debugging a detached process, i.e. a printer spooler.  In order to do this,
DBG$OUTPUT & DBG$INPUT must be directed to a terminal device.  However, this is
inconvenient now that just about every terminal we have is being connected to a
DECSERVER port, particularly all our modems, which means I can't work on it at
home.  Has anyone found a way to do this?  Thanks.
								Mark

rrk@byuvax.bitnet (07/04/88)

If you have CONTRL by Clyde, send the DBG$INPUT and DBG$OUTPUT to the terminal
you normally use at work (it doesn't even have to be turned on in most
circumstances) and the use CONTRL to monitor that terminal to access and
leave the debugger session.  In absense of that, it is not a nice solution...
If you have excess modem lines, which are all set up for outgoing, as well
as incoming use (via reverse-LAT ports and something like kermit) send the
debugger I/O to one of these ports, and then use kermit to dial out another
line and into the line where the debugger I/O is going to debug the session...
If you lack excess modem lines, you may even be able to do it on a single
line:  you still need reverse lat ports set up.  Probably all solutions
using reverse-LAT on modem ports require that the ports be set up dynamic
access with fixed speed (autobaud disabled) for the primary speed of the
modem.  Define the debugger input and output to the reverse LAT port on
which you are logged in.  Then start the queue and log off of the terminal
server port.  As soon as you do this, the system symbiont debugger will
seize the port and start running debugger I/O to it.  You will need to dial
back into the same port as you did before, and you will be in the debugger.
 If you think this will be difficult, you are right!  It will probably take
a while just to get your port set up right, but I've done it before.

Now let me take this opportunity to make you sick and tell you how I do
it now:  At home I have a 9600 baud modem with a 3 port statistical
multiplexer, which gives me essentially 9600 baud connections to 3 separaate
terminal server ports (yes, I own almost half of a DECServer 200 from home).
 I just set up a reverse-LAT debugger connection to one of the "extra" ports
and start the queue from one terminal and have debugger prompts come up
on another...well, I had to work for it.  Good luck!