UNIBUS powoer on/off spec

[Noel Chiappa]

So, I looked at the early editions of the "pdp11 peripherals hanbook", which
have good, detailed discussions of UNIBUS operations (at the back; chapter 5,
"UNIBUS Theory and Operation", in the 1976 edition), but in contrast to the
level of detail given for master/slave operations, and bus requests and
interrupts, the level of detail on power up/down is very low, especially
compared to that in the later "pdp11 bus hanbook" (which, as mentioned, does
not seem to be online yet, alas). So, I have transcribed that section, and
posted it:

  https://gunkies.org/wiki/UNIBUS_Initialization

I have yet to scan and post the associated timing diagrams (which are useful,
but not critical); the desktop that runs my scanner is down at the moment,
alas. (If anyone who has a copy would like to volunteer to scan them, that
would be great.)

	Noel