Inside a DEC PDP 11/34 computer from 1978 (PWJ26)

Programming and teardown of a DEC PDP-11/34 from 1978

The Boot-ROMs on the bootloader card are funny. You need one for every device you want to boot from. The position of the roms determine the boot order. The are like pluggable device drivers. Hence the word "plugin".... (maybe :-))

[markcummins]

I was hired in 1978 by Digital Field service. I was factory trained on the 11/34A you have here. I miss working that world of technology.I retired from DEC after COMPAQ obtained them. I Supported all members of the PDP-11, VAX, and ALPHA's. I still have all my maintenance gear, books, and Micro-Fiche. It is all in storage. I have not looked at it in over 12 years. Thanks for the refresher.

[arvizturotukorfurogep]

"Every bus needs a terminator"
And I pictured public transport buses with Arnold Shwarzenegger on board lol

[renehoude]

I work for DEC has a service tech, from 1976 to 1999. I have worked on all the PDP 11 line, PDP 8, PDP 9. The PDP 11/34 was very popular in those days. It was very pleasant to work on the 11/34.

It is bringing me lost's of memory.
Thank you for showing it.

[davidbarts]

"Because computers came from IBM." That leaves out the details of the reason DEC called them "programmed data processors:" many companies had policies that one organization was responsible for all computing, and forbade teams from purchasing and setting up their own computing facilities. The approved, central computing resources typically involved IBM equipment. Calling their equipment "programmed data processors" meant that purchase orders for them would fly under the radar of purchasing departments that would disallow purchases of "computers".

[microdubber]

I hope you put that baby back together. A working 11/34 is worth much more than the scrap.

[bitcoredotorg]

Those backplanes were fantastic looking. Massive core memory (wow!), and beautiful memory boards.
I enjoyed this, thanks for filming!

[richardgregory]

Takes me back. My first job in IT was operator for two PDP machines running the admin software for a college - an 11/34 with two RK07 drives and an 11/44 with three RL02's and a tape drive, both running RSTS/E with DECnet. These were pretty old machines even by that time and they were woefully underpowered for the demand on them. It was quite a step up when we moved over to a MIcroVAX-II!

[ElektronikLabor]

Deine Videos sind der Hammer; du erklärst kurz und sachlich. Du hast definitiv mehr Zuschauer verdient!

[josepllorens]

I liked it a lot. You mention that the core memory did not work. This memory needs to be supplied by +20V and -5 V. Power supply H754 provides these voltages.
In minute 18:17 I can see that this power is missing. Without these voltges the core memory can not work. Congratulations for these vídeo.

[jeremyelectronic]

incredible - I'm so thrilled to have an in-depth look at something I've always want to understand which was a bit before my time... much appreciation and much respect

[ntyham]

We had two PDP 11/34's in my laboratory at Washington University in St Louis in 1979. Each one had 64k words of memory and two RL-01 disc drives. We did a lot of really great scientific work. One was used for general scientific computing, and the other was used to control a JEOL JXA-733 electron microscope / X-ray microanalyzer.

[glamill]

That is one helluva clean BA11s box !!
I was factory trained on 11/34, 11/44 and 11/780 way way back in the 1980's.
I still fix them today - currently an 11/70.
I have not lost the art of fault tracing and chip changing !!

[stephenwabaxter]

Thats a very early machine. The construction is similar to a very old machine we had at General Instrument Microelectronics back in 1982 - it was ditched soon after I joined - we built a new factory so only the useful kit came with us. Later I joined Digital Equipment in Ayr having used their equipment extensively in the Semiconductor Industry. In the Early 1990 that was when Digital failed yet again to enter the PC market successfully and made strategic errors over UNIX et al. We closed the Galway facility in Ireland and its just so hard to keep a company afloat when some bad decisions have been made.

[SirBunghole]

I use to program these things. RSX 11M Plus.... oh the memories....

[cnnw]

These old PDP units are worth a lot more than their scrap value!

[tomtalk]

Those system cards are beautiful. Love a Dec computers, RIP.

[jimsvideos]

Think of how many housecats that thing could keep warm!

[DECcomputers]

I didn't know that DEC always used non-magnetic screws, but it explains why I regularly wonder why I often need pliers or tweezers :)

[DandyDon]

I worked in a rental car company where the processing center had 9 PDP 11/23s for the reservation center and a PDP 11/08 for the ARINC or (airport reservation interface). I did the back-ups and file transfers every night on grave yard shift.

[roysmith]

A blast from the past. I worked on an 11/45, and later an 11/34. DEC had some great engineers, but the short little bus grant continuity cards were an unpardonable sin. I can't tell you how many knuckles I tore up getting those little things in and out. It would have hurt them to put another 8 inches of fiberglass and a handle on top so you could pull them like any other board?