There are several binders that cover tape, graphics,
terminal, I/O and
so on. I can try to scan it if you like.
That would be good to have scanned. I have machine-readable versions of the
base firmware for the terminal.
I also have the complete
maintenance manuals for the terminal and interface boards, including
schematics, but they are difficult to scan due to the paper size.
I have most of the manuals scanned (there were MANY options available for
the 264x). The only practical way to scan the 11 x long sheets of schematics
HP uses is with a wide sheet feed scanner (like the Ricoh IS520 or Kodak 2500d)
and do it in overlapping sections.