Once again I am going to throw more rocks, I have XXDP on disk (RL) and other then proving things work that are already working I have found it to be almost useless, some of the trap test and thing may localize you to a general section but beyond confirming that a card has failed I have little use for it beyond that. At least that’s been my experience, but that’s me and as my wife will tell you I am not exactly the sharpest tool in the shed.
The last six months or so have been working with Data General Nova platforms but have done a couple Q and Unibus systems and have a simple routine for bring them up and on line. First: Get the local interface working, regardless of it is ODT, local keypad or switches and lights. Once you have that then you can write to memory, read from memory and push and pull from I/O devices. From what I have read sounds like you got that nailed. Second: Working in assembly run some simple loops, I love increment a registers by one, send the results to the printer and then jump back. Third: drive interface and OS, if a system will load and run an OS there is not much else it won’t do. I have found problems with CPU cards that will allow them to run simple loops and the like but not allow them to boot RT-11 but will still work just enough to load the XXDP service pack. The diagnostics will point to the obvious like you have a CPU or memory fault but my experience has been old fashion card swapping and a familiarity with addresses and assembly language are way more useful.
This is why I propose getting an OS to load first and not spend any additional time trying to see what software may run and what wont. You have completed steps one and two and now just need to get past step three. Maybe the thing would be to get your drive, pack and controller and confirm they work in another system first and then see why they won’t work in the 11/40? That’s what I would do myself. I like the approach of testing every system like I/O, drives and memory in a known working system first and then knowing they are functioning and after that it just brings it down to card placement, backplane configuration or CPU issues and from what I recall you have two of those systems so you got spares along with your other working Unibus system. As much as I hate to say it maybe the thing is to try to push the relevant XXDP test for the 11/40 from the GUI and see if they run? That will at least confirm if there is a CPU card issue.
I was just up in Wilmington this last weekend and although I do try to avoid going above the canal as much as possible it’s not an unknown event. It may be best to bring your drive and card down here and we can run it up on my 11/34