m_thompson
Veteran Member
I have used Sullins connectors for decades, and had good luck with them.
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History and start of life of my strange 11/45
- Thread starter Activmaker
- Start date
Ed Groenenberg
Experienced Member
After a long period with a lot of issues , I am back with new infos : My strange 11/45 is now functionnal and can boot XXDP2.2 XXDP2.5 RT-11 and RSX-11 M . I am really happy to have my system working .nfire:
What problems I discovered :
When I started to test my RL11 board , the system became instable . I suspected something wrong with the new board but even whithout the RL11 , issues were present. Problems was intermittent. After a long period of tracking , I discovered that some backplane connectors was damaged ! . I was using EDAC connectors , but the quality was poor. The only choice I had was to re build a new backplane with others connectors (I use now Sullins ). Making a backplane need a long time (Lot of soldiers + wire wrapping ).
After that, system came back, but not for a long time
Since the system was stable ,I started diagnostics of RL11 . I took a long time , but finally all diagnostics passed !
XXDP 2.2 was functionnal , but none of other
XXDP 2.5 Was now functionnal.
RSX-11M was not booting with a lot of errors messages, and RT-11 Stop in HALT instruction with a PC at very strange address.
I started to analyse source code of RT-11 , trying to follow what happenennig during boot..It was a really hard job !! :shock: . After many weeks of debugging , I discovered that some instructions in CPU didn't set the carry bit correctly ! Instructions was RORB,ASLB,ASRB . I was surprised that CPU diagnostics didn't find these issues !
After fix of instruction implementation, RT-11 was functionnal, and RSX too !
Next step is now to make more tests, finish some improvments in code, and starting thinking about the box and of course making blinkenlights panel !
Comments are welcome...
That's quite an impressive build and journey!
Ed Groenenberg
Experienced Member
Well, SETASI did it with their 11/70 implementation. That consisted of 4 (maybe 5) boards which replaced the complete cpu & fpu boardset.
Oh, and apparently the console became obsolete too.
bqt
Veteran Member
You have any information about that one? I wasn't aware that they had such a product. I know about the PEP-70/HC-70 boardset, which was 5 boards, and replaced the cache and memory boxes for the 11/70 (I would love to get a set). And I know that Quickware did an 11/70 CPU replacement, which left pretty much only the front panel, and replaced everything else with just one or a couple of boards.
But those are the only ones I knew about.
Ed Groenenberg
Experienced Member
Arg, I used to have some pics of the boards
It is the QED95 boardset.
Some info is on Henk's site : https://www.pdp-11.nl/pdp11-70/special/qed95.html
THE PEP-70 was indeed a memory option, and they also made a UCI/UCH option,
which is basically a Unibus signal amplifier/buffer and can replace them backplane-to-backplane jumper (M780?)
bqt
Veteran Member
Arg, I used to have some pics of the boards
It is the QED95 boardset.
Some info is on Henk's site : https://www.pdp-11.nl/pdp11-70/special/qed95.html
THE PEP-70 was indeed a memory option, and they also made a UCI/UCH option,
which is basically a Unibus signal amplifier/buffer and can replace them backplane-to-backplane jumper (M780?)
Ah. Ok, then we're talking about the Quickware replacement.
By the way, while the QED-95 is as far as you could take an 11/70 speedwise, it's not the fastest hardware PDP-11 around. Quickware also made Qbus PDP-11 replacements, and the QED-993 is much faster. That do have (as far as I know) the title as the fastest hardware PDP-11 out there.
The PEP-70 is the memory replacement, yes. One board you put into the CPU chassis instead of the memory boxes on the memory bus. However, if you only have the PEP-70, you still retain the 11/70 memory controller and cache boards, and the machine runs at a similar speed as before. It's a nice improvement, but don't do much for performance. It does reduce power consumption, and improve reliability.
That's where the HC-70 comes in, which replaces the four boards of the memory control and cache. The HC-70 makes all memory look like cache, and do give a pretty nice boost to performance. But it can only be used in combination with the PEP-70.