OK, that makes sense.  As I said, I thought MAXC was a Nova.  So, Stanford used a direct interface to the 10 and the CMU, DEC and MIT ones used an 11/20
I don't know how many others were stood up or how.

On Fri, Jul 31, 2020 at 4:00 PM Bruce Baumgart <bgbaumgart@mac.com> wrote:
Lars et al
Lynn Quam is credited with building the XGP hardware interface to the SAIL PDP-6.

A few lines from
Version #1 of Quam’s file RESUME[DOC,PDQ] say

< quote >

Nov. 1972 to
Feb. 1973\jFull-time research associate in computer science.
Received a grant from the NASA Viking Mission thru 
Cornell University for the analysis of candidate landing
sites for the Viking mission.\.

\jDesign and debugging of an interface between a PDP-10 (PDP-6)
and and a Xerox Graphics Printer (XGP).\.

< Unquote />

Prior to the Stanford interface,
Quam built a Nova to XGP interface at Xerox Parc
As a part time employee while also working at SAIL.

p.s. Lynn Quam’s log in code is PDQ

On 31 Jul 2020, at 12:38 PM, Lars Brinkhoff <lars@nocrew.org> wrote:

Clem Cole wrote:
Anyway, I'm pretty sure the [XGP] copies at Stanford (Jan '73), and
MIT (was the 3rd in the series and a little later) also used 11/20s or
maybe 11/15's which was the OEM version of the 20 as it was March '72
when the CMU XGP was first stood up.

Thank you.  That's one more "vote" in favour of 11/20.  In which case
the TV-11 ought to be an 11/10 which was our original guess.  I don't
think it matters to the software; it should run just as well on either

I have seen MIT files which describe the Stanford hardware, so it seems
their inspiration came from there.  The earliest timestamp is from
February 1973.

I got the impression the Stanford XGP had a PDP-6/10 IO bus interface
rather than going through a PDP-11.  I'm CC'ing Bruce Baumgart.