Not strictly related, but this reminded me of the IDE
adapter plans
 for Qbus and UNIBUS that were floating around some years back. 
I was helping with one, once upon a time.  What evidence I can find
says this was around February 2002, but I'm not sure whether that's
when I was working on it or a timestamp corresponding to something
else, like when I last copied the files.
I never saw the hardware.  The person who was working on the hardware
gave me remote console (and network) access to the machine; I was
trying to write a driver for it for NetBSD/vax.  I never got it
working.  The project - from my point of view - kinda fell apart while
I was still struggling with, based on fuzzy memory, some kind of
addressing issue.
I still appear to have all the code I wrote, in case that matters.
                                        Mouse