[Info-vax] DECserver/LAT across DECnet areas?

[terry-...@glaver.org]

On Saturday, July 22, 2023 at 7:53:21 PM UTC-4, Robert A. Brooks wrote:
> In the olden days, a terminal server needed a DECnet address in order to be MOP 
> downline-loaded. 

The DECnet address is also used for OPCOM messages which are
emitted in the standard Phase IV format.

DECservers can specify a an image file they want, or they can expect
the load host to send them the right image based on their Ethernet
address. Some can go either way, some insist on one or the other.
"Serve image based on MAC address" was added for the DECserver
500/550 because the configuration is bundled into the load image as
the 11/53 processors in those systems only had a few dozen bytes
of available non-volatile memory - nowhere near enough to store the
config.

30+ years ago (Yikes!) Digital Canada paid me to write a MOP imple-
mentation for RSTS/E. Since the system programming language on
RSTS/E is Basic-Plus 2, that's what it is written in (except for a tiny
piece of Macro-11 needed to enable multicast reception). It is com-
pletely standalone. As long as the RSTS/E version supports Ethernet,
it will work. Doesn't need a DECnet license or anything like that. It
faithfully minics the OPCOM messages on VAX/VMS:

         Event type 0.3, Automatic line service
         Occurred 06-Jul-90 02:48 AM on node 3.4 (SPC11D)
         Circuit UNA-0, Load, Successful, Node = 2.6 (LT2006)
         File = PR0801ENG.SYS, Operating system
         Ethernet address = 08-00-2B-0A-FD-30

I did get a "bug" report. A customer tried it on a LAN that also had a
VAX 8978. The poor little 11/23+ with its MOP written in BP2 was
answering before the big, bad VAX. I had to add a delay option to the
configuration file so the RSTS/E system would wait a second or so
before servicing the request, to give the VAX time to get around to
it.

I threw in an implementation of "NCP CONNECT NODE" for free, too.

You can find it at https://www.glaver.org/ftp/tmk-software/mop-server
Give that server a little time to respond - it is hauling a virtual Alpha
out of the freezer to serve those files.

I also wrote a DECserver 5x0 configuration utility for RSTS/E. That
isn't available, though, as the way the config was stored in the image
was covered under NDA.