A suggestion is to add info-pdp11 to these kind of questions, since some of us don't really have the energy to plow through all of cctalk... :-) Anyhow, just like some others have suggested, it definitely sounds like a hung Unibus. Check NRP jumpers on all the slots. Remove the massbus interfaces. See if you can access anything in the I/O page. Those are the first things I'd try. Also, the 11/70 have different regulators for different parts of the backplane, and one regulator us just for the Unibus slots at the end. Check that regulator as well. Also, I hope you have a good terminator card. :-) Johnny Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt(a)update.uu.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol