On Mon, 09 Apr 2012 23:45:48 +0300, you wrote: The museum guys posted this user's guide: http://www.bitsavers.org/pdf/dec/pdp10/TOPS20/V7/USERS.MEM.txt The full "collection" is at the following address: http://pdp-10.trailing-edge.com/BB-PBQUC-BM_1990/index.html These are the latest available manuals (and among them there is the one you have linked too). I've already read the User's Guide and the System Manager's Guide, but I find some things not so clear. I'll have to do some more experiments. :) Unfortunately the full TOPS-20 Notebook set seems to be unavailable: I've hunted for it high and low, but to no avail... :-\ G.