----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
Sent: Saturday, October 06, 2001 4:07 PM
Subject: Re: Rebuilding the PDP 11/34 (2volts?)
> Got it reassembled and turned the switch, the
lights came on and
> voltagages tested at +-15, +5 and one at +2v
> We were expecting the 15 and 5 but not the 2 is this just an
with the unit partially disconnected?
The 15 and the 5 sound right. The 2V could be one of the nominally
TTL-level signals to the backplane -- ACLO or DCLO (basically power
lines) or LTC (line time clock, a pulse at mains
frequency for the
heartbeat interrupt), for example. What pin of what connector did
find it on?
I'll have to double check that but that is what we figured.
> Also have a few BC11A cables for connecting the
units but the main
> unit seems to have all the slots filled and a terminator at the
You pull out the terminator and connect a BC11A cable in place of
Then connect the other end of that cable to the Unibus
the first expansion box (or whatever). Carry on
linking the units
together and put the terminator in the Unibus Out slot of the last
I found another PDP 11/34a this afternoon from the same place as mine
originally came from. This one had 1 RL01's a RK05 and a Tektronix
400? terminal on it. I was able to check out the cabling. The RK05's
were connected by a wide flat ribbon as well coming out of the case
from the same line as the first card of the controller
I managed to get the face plate for my DataMedia terminal, and saw 2
PDP 11/44's and a Huge DG sitting in the rain. There was also a box
with a Q-bus on one side and a unibus on the other. Unfortunately I'm
out of space.
Also a headstart advantage and a HP Envizex at another stop.
Does anyone know about the headstart advantage?
There are several unidentified cards still remaining
versatech 289 380211 with 2 teledyne philbrick 4023 10bit D/A
Is that 'Versatec'? I associate that name with fairly high
printers (200 dpi electrostatic matrix units) and
plotters. Maybe a
plotter interface acard or something.
I'll post a better description when I get back into the garage with