On Tue, 25 Oct 2016, Guy Sotomayor Jr wrote:
OK, re-reading the first part of section 5.2.5, it?s
pretty clear that the Unibus is 120-ohm:
A bus terminator is defined as a Unibus element or part of an element containing
a resistive network which connects to the end of a Unibus segment and matches
the 120-ohm characteristic impedance of the Unibus transmission path.
Or to cite another source: PDP11 Bus Handbook page 76 says
"A bus segment consists of a terminator, a 120-ohm transmission path
(cable) with options having drivers and receivers, and another terminator
(in that order)."
Christian