My past experience has been that, if you can find the right person within
DEC that is willing to go to bat for you, then you can get the documents
under a non-disclosure agreement.

My understanding is that the documents have never been cleared by their
legal dept. for release. I think their concern are comments in the
documents like "this design is problematic and will not perform as well
as a company XYZ box ABC".

There are a few documents that are useful, if you are willing to poke
around and read between the lines:
- VAXstation 2000 Technical Manual (covers the KA410 and chips in detail)
- DECstation 3100 Technical Manual (this one used to be somewhere under
	decinfo on gatekeeper.dec.com anonymous ftp, hopefully it still
	is:-)
(The first should still be orderable from DEC for $100 or so?)

Also, you can snoop around in the pmax source tree, since several of them
used the same chips as the VAXstations did.

Good luck with it, rick