Rebuilding the PDP 11/34 (2volts?)

From: Mike Kenzie <>
Date: Sat Oct 6 16:56:20 2001

----- Original Message -----
From: "Tony Duell" <>
To: <>
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
> > of testing 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 In connector
> 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 set.

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
> > convterers
> 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
some light.
Received on Sat Oct 06 2001 - 16:56:20 BST

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:34:17 BST