On Thu, 12 Jan 2012 00:01:21 +0100, you wrote: Joe. I believe DECnet V4 might be the latest. I think so too. Afraid I don't know the magic incantations though. Checked the manuals? Few hours ago, after my first answer to Joe, I've discovered that digitized docs about TOPS-20 in general (and DECnet-20 in particular) are quite scarce. Just for comparison: TOPS-10 software notebooks are almost complete while TOPS-20 ones are almost absent... :( G.