[TUHS] Memory mapping device used on PDP-11/20 Unix

[Noel Chiappa]

So the "Odd Comments and Strange Doings in Unix" page:

  http://www.bell-labs.com/usr/dmr/www/odd.html

mentions (at the bottom) a "PDP-11/20 with KS-11 add-on". I'm trying
to find info about the KS11, but haven't been able to locate anything.

Does anyone have info on it, or, failing that, is there source for an early
version of Unix that uses it? (I can create something of a User's Manual for
it by reverse engineering from the source.)

Thanks!

	Noel