PDP 11 repairs in progress

devin davison lyokoboy0 at gmail.com
Tue Jan 15 23:11:23 CST 2019


Hello, ive been reading on the list here for a while. I'm usually in the
background not seen much, I figured i would give a status update on my pdp
11/34 system. I have been moving quite often for work over the past couple
years, and still have not gotten my machine running since picking it up
over 3 years ago. Thankfully I have all of the equipment and peripherals in
one place now, and am hoping to get this thing finally running soon.

I had picked up an entire truckload of a pdp 11/34 system. Its an 11/34
with a tape drive in a separate rack, 2 rl02 drives and an rl01. Lots of
disk packs and terminals. I fought with some power supply troubles at
first, but after some part swapping i got the machine to power back up. As
of right now, i have a minimal machine that i can key in programs on the
front panel. I was able to enter programs through the front panel that
would display on the vt100 connected via current loop.

Thats pretty much the state of things right now. The system is in a minimal
state,most of the cards are removed for troubleshooting. i wanted to test
the hardware and see if i can boot to a disk packs. My disk packs appear to
be loaded with RSX.

I was trying to switch from current loop to rs232, so i can connect the
machine to a modern computer with a serial port, and dump diagnostics over
the line to test the machine. I have tried wiring up the cable, but am
getting intermittent garbage on the terminal. Thats pretty much the hangup
at the moment. I hope to over the weekend troubleshoot it further and get
this project moving again.

There is a lot of local activity here with all the hacker spaces and
amateur radio folks, i really want to get it running in some kind of public
manner that others can interact with, perhaps some kind of telnet gateway
or over ax.25 packet, but thats later down the line once its running.

There is also another 11 I am picking up in Georgia in the following week,
so i have that drive ahead of me. Not even sure i will get started checking
the other system out till the 34 is running.

Well, thats about it for the state of things and my progress.  Once i get
things cleaned up a little better ill post back with some pictures of the
current setup.

--Devin D.


More information about the cctech mailing list