From mboxrd@z Thu Jan  1 00:00:00 1970
From: johnh@psych.usyd.edu.au (John Holden)
Date: Mon, 2 Sep 2002 12:19:13 +1000 (EST)
Subject: [pups] Unix and PDP11/20 (was PDP-9?)
Message-ID: <200209020219.MAA32566@psychwarp.psych.usyd.edu.au>

Early editions of Unix did run on a PDP11/20, written in assembly language.
There was a memory mapping option KS-11 that sat between the processor and
Unibus that mapped chunks of memory. It was a DEC special, and only about a
dozen were built. See http://cm.bell-labs.com/cm/cs/who/dmr/odd.html 
A hardware story'