>>> I keep wondering about the psu. >> >> Good theory. > > I'll give these a double-check...
I did give these a look yesterday. Indeed, the +5 regulator in position "C" (which includes supply to the KT11) was running a little low (4.9 and change). I trimmed it up, and checked the rest of the regulators while I was at it (they were all fine.) This did clear up some small strangenesses I was seeing at the console in address translation mode, but "ls" still fails in exactly the same way. --FritzM.