Booting PDP from VAX

[spiceminer]

Dear all!

I am trying replicate a setup where a PDP11/23 with DEQNA Network interface booted from a VAX.
OS on VAX side was VMS 5.5, OS on PDP side was RSX-11M.

Unfortunately the VAX is dead and I am currently unsure if the VAXes harddrive is still intact and if the configuration is still usable.
In a few weeks I am again on site to check the drive with another VAX.

Does anybody know how this could be accomplished, what Software is required on VAX side with which configuration?

I only know that LAT and DECNET has been used (but as far as I know, RSX supports Decnet III and VAX / VMS Decnet IV)....

Thanks for your thoughts....

best regards
Stephan

 

[Bitly]

Disclaimer: I know nothing about this subject.

If memory serves, certain 11/23 CPUs contain boot ROMs that know how to control a DEQNA, so my guess would be the 11/23 would try to boot from a MOP server hosted by the VAX. The boot file should be named based on the ethernet address of the DEQNA with a .SYS extension.

I think the MOP server is built into VMS, but haven't used it myself so it may be a layered product also (or a subset of DECNET). If you can track down the boot file on the VAX drive, you could use one of the Linux clone MOP servers instead, unless it is also serving files from the VAX.

Another option would be backup tapes for the VAX. There is a program vmsbackup (search github) which allows extraction of savesets on linux.

CW

 

[daver2]

Correct.

The PDP-11 has a bootstrap that boots over ethernet from the VAX using the DEQNA. Device Xx (I can't remember what the letter 'x' is just at the moment).

The VAX disk should have been backed up of course...

Dave

 

[daver2]

XH device...

Dave