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hi, PDP 11/45 found at Attic? What is this?

patrickdafunk said:
Seems the PDP 11/45 are quite rare, I didn't know I had this in the ATTIC. It's pretty awesome to find! Could somebody please tell me how much it is worth?
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It's kind of like finding an old car in nice shape. To a collector it might be worth something, but some guy who just wants to be able to drive to work wouldn't think it was worth anything. This computer, if it works at all, will only run very old software that would not appeal to the average person. And it will take far more maintenance than a modern computer. To a collector it might become a labor of love, but to everybody else they are just nuts.

We can't really tell the condition from the pictures we've seen so far. The 11/45 could be complete, or it could be a more-or-less empty box, or damaged internally in some way. There might be enough parts to build a working system, but I think you do not have everything needed to hook together the parts you have. I think to get serious bids you will need a lot more information about condition and a complete inventory. It is hard to guess if an 11/45 would sell for more than the sum of its parts, but it is probably a lot easier to sell a complete and/or working system.
 
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The DEC PDP 11/45 has now found a new home - mine!

I hired a small van the other day and slipped over on the ferry from Harwich to Holland. Just got back today and unloaded everything.

It is in remarkably good condition and appears to be a full system + some extra 'bits'. To identify exactly what 'bits' I have - I will have to do some 'computing archeology'.

I will create a new thread under 'DEC' and list what I have unearthed - and I am sure I will have many questions about how to go about the restoration.

Dave
 
Hi Dave, Congrats on getting the 11/45 and stuff, quite a trip by the sound of it! glad its gone to a good home, I never ever had a reply to my messages I sent the seller, which proved good for both of us, as I pursued another sytem which was for sale, so by luck and coincidence I too recently ended up hiring a large van and collected some interesting Dec items including a 11/45 complete in its racks with drives etc. I will be following your progress with great interest, and maybe I also can get my machine to some sort of working order.
best of luck Harry
 
Hi Harry,

I was going to send you a PM out of courtesy to tell you that I had picked the system up. It was a 'real' system after all...

Yes, the trip was interesting - but actually enjoyable as I turned it into an adventure. I caught the Harwich to Hook of Holland ferry on Monday night (arriving on Tuesday morning). Packed the gear up and caught the evening ferry from the Hook of Holland to Harwich arriving Wednesday morning. Got back to home in Worcester around 11:30 AM. Had unloaded everything apart from the 11/45 by 12:15. I had been thinking about how the h*ll I was going to unload the 11/45 itself all the way back from Harwich! Fortunately, my next door neighbour returned from work at lunchtime so I had another pair of hands! Job done and van returned.

I have been taking copious photographs of everything - and I have created a notebook to keep all of my discoveries, thoughts and investigations/experimental results in to document the process of reviving the beast. The next thing I will be doing is to inventory everything I have and post that in a thread I will create under the DEC forum. The system I have is pretty much an 11/45 chassis with the CPU/MMU and FPU cards loaded. I eventually found the original memory cards - they were in the system all along - just not where you would have expected to have found them! This also explains the missing memory slot voltage regulators from Bulk Supply B (they aren't required - hence they weren't fitted). I also have 5 or 6 off 16K MOS memory boards - which seem to have been 'extras' that were not originally fitted to the system.

I have the TU56 DECtape unit and the TC11 controller which I probably don't require for my purposes. There appears to be a separate Plessey disk controller - but no disk drive unit. This is OK as my plans were to acquire either an M7846 (RX01 UNIBUS disk interface) or an M8256 (RX02 UNIBUS disk interface) and run the system from my Raspberry PI via a simple interface I have built and some emulator software written in Python to emulate the disk drive subsystem. It should be possible to patch the disk drivers for whatever O/S I decide to run to think it has a much larger block-structured device than would have fit on the physical floppy drives of the time (i.e. the Raspberry Pi will effectively become a large - but fast - emulated floppy disk drive).

The next thing on my list is to find a console port (DL11-W card or siblings), terminators and bootstrap card. I am then going to clean up the power distribution Unit and the Power Supply Units and reform the electrolytic capacitors before getting the power supplies up and running. I will perform a simple portable appliance test on the PDU/PSU to make sure I have a good earth bond and the insulation resistance is OK before doing anything. I will also get an earth leakage breaker and replace the DEC PLUG with a more sensible unit for the UK. I bought some bits for the Church's new Baptistry Heater from Toolstation - so I will let you know what I get. Obvously - one key thing is to check what Voltage the machine is set up to accommodate before connecting it up - otherwise some major damage can occur if configured for 110V and you plug it into 230V!!!

Mine is missing one of the front panel knobs and (of course) the key. Next thing to read is the DEC sticky thread on getting a new key cut!

I plan to house my system in a small, portable rack that is mobile.

I am glad you tracked down a system for yourself. It looks much larger than the bits I have - which is good as it appears we are both happy with our respective finds and that is potentially two 11/45's saved from the dreaded recyclers!

Where are you based in the UK out of interest? Can I suggest that you do the same and create your own thread and perhaps we can collaborate. We may have some "swapsies" or we might be able to help each other out with loan cards if we suspect a card problem. I have access to a full suite of test equipment (decent oscilloscopes, logic analysers and the like) if either of us runs into trouble.

It might be helpful to find some other 11/45 owners in the UK. Anyone out there reading this thread???

Regards,

Dave
 
Hi All;

Dave, and Harry Congratulations !!!!!!!!!!!!!!!!!!

You are among a fairly small elite group..

Dave, "" I eventually found the original memory cards - they were in the system all along - just not where you would have expected to have found them! This also explains the missing memory slot voltage regulators from Bulk Supply B (they aren't required - hence they weren't fitted). I also have 5 or 6 off 16K MOS memory boards - which seem to have been 'extras' that were not originally fitted to the system. ""
The Extra 16K Mos memory will not go where the (I think you say) other Memory Boards go, But, If You have a Four or more slot UniBus, The 11/45 can run with both.. The memory from about slot 20 to about 26 will only work with what I think is the system memory boards, but they are or were faster than the Mos memory.. The 11/45 will run just about anything memory wise..
So don't get rid of the 16K mos boards yet..

THANK YOU Marty
 
Hi Dave,
I am at present struggling for space,( same old problem!) and have to clear a storage area at my workshop to accommodate the latest Dec stuff in the h960 racks, Luckily a friend is storing things in his unit,while I make some room, I have not yet had chance to even examine things or make any records of the existing 11/45 set up. I am located in Somerset, If I can help with anything, just let me know. I do have a second 11/45 which is incomplete,it was also missing both control knobs, but does have its key, I can get keys cut locally, and I am sure I have some spare blanks, if its a help .
Marty.. I had been trying to keep up with the progress you had been making with your 11/45, your detailed account of things, no doubt will prove valuable when work begins on these.

........Harry
 
daver2 said:
... Got back to home in Worcester ...
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Congrats on your acquisition ... I used to work in Worcester, early '80s at Froude in Gregory's Bank. Lived in Droitwich.
They had a Control Data mainframe at the time, if I recall.
 
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