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kyeakel
August 23rd, 2011, 01:32 PM
I was just gifted with a PDP 11/83. It's a rack mount dual chassis unit. It has a floppy and tape drive and 2bays for hard drives. I looked on bitsavers, they don't list this machine. Since it's very heavy the previous owner tried to separate the 2 chassis. They are connected together with a frame, and a hinged back panel. Inside the back cover there are many ribbon cables, some of which have been disconnected. I can't open the hinged cover very far as there are a large number of serial ports on it. I can see where one of the cables goes, but there are 3 others that look to go to cards. One is marked "tape". I will be taking some pictures over the next few days.
Does anyone know: what the proper way is to open that back cover? What hard drives should I look for? Which serial port should I connect to to get a console? I'd like to run UNIX on this, will I find the distro and can I get it to the DEC's floppy format?

Thanks for any help,
Kipp

NeXT
August 23rd, 2011, 02:34 PM
Hey! Welcome to the 11/8x club.
Yeah, it sounds like photographs would be a good start. I'm having a tough time seeing your system in my head.

tradde
August 23rd, 2011, 03:00 PM
Hey! Welcome to the 11/8x club.
Yeah, it sounds like photographs would be a good start. I'm having a tough time seeing your system in my head.

Same here. I wanna see some pics.

jackrubin
August 24th, 2011, 04:12 AM
The 11/73 and 11/83 use the same CPU with different memory configurations. The KDJ11-B CPU Module User's Guide (EK-KDJ11B-UG-001) from bitsavers will be a big help in getting started with this system.

Jack

kyeakel
August 24th, 2011, 12:52 PM
Here are some pictures
65176518651965206521
The 1st picture shows it with the covers on, when I took them off I found the dual floppy drive hidden there (see 5th picture).
The previous owner said it worked before he removed the cables in the back. I have not yet powered it on.
The 2nd picture shows the rear door. It's hinged, has 2 7-segment displays, 12 serial ports, some ports at the bottom that I don't know, and the port under the 7-segments that I think might be the console.
The cables that have been removed either go to or come from the rear door. I can see where 2 of them go, but not the other 2. I also see that one of the 1/2 width cards in the upper rack is out of it's slot and tipped toward the metal bottom of the cabinet.

I wanted to open this door, take pictures, remove and clean the cards and chassis, and then reassemble. The door won't open farther than it is due to the cable routes.
Kipp

Al Kossow
August 24th, 2011, 01:31 PM
What hard drives should I look for?

There are no hard disks in what you have. If you're lucky the controller driving the
floppies can be used in the top chassis where the MFM controller cables are coming
out to the front.

'tape' is for the TK50 tape drive in the lower chassis.

This system probably had RA series external drives connected to it through the
small connectors on the back panel.

There is going to be a fairly large disk controller board connected to those small
cables on the back.

DOS lives on!!
August 24th, 2011, 02:52 PM
Wow, those are some big power supplies! Have you turned it on yet?

RSX11M+
August 25th, 2011, 11:56 AM
If you haven't already, please go no further with your current disassembly efforts, and whatever you do, DO NOT plug it in and TURN IT ON.


Some general comments...

The boards in this assembly have no protective coatings, so please carefully return the top cover, and re-fasten it in place to prevent accidental contamination. [ That's a memory board there BTW ]
http://96.11.235.30:9080/supplemental/DEC PDP 11-83 058.jpg

Everything you need to do should be accessible from the rear.

What you have there is two BA23's coupled together in that assembly. [Ganged together for I/O space and power] A special back panel is placed across them, which has been partially removed in the wrong sequence. [which is why you're having difficulty now] Note the safety tether wires dangling down, disconnected in this pic. These were meant to take the weight of the removable rear cover.
http://96.11.235.30:9080/supplemental/DEC PDP 11-83 056.jpg

To proceed safely, please locate another "table" slightly lower than, but in addition to, the one it's now resting on, and position it to receive the rear panel assembly. [It's too heavy to hang by it's ribbon cables]

Once that is done, try removing the two screws in the upper right corners of the rear panel.

http://96.11.235.30:9080/supplemental/DEC PDP 11-83 057a.jpg

This should free the cover. Lay it face down on the new table, exposing the cables that connect it to the individual PC boards.

------------

This will get you to a safe place, where we can help you identify the boards in your machine. My quick assessment would be that it may contain two RLV12 controllers, that I doubt you will be able to locate RL01 or RL02 drives for. These are probably the two black connectors along the bottom of the rear panel.

I think this unit once contained it's internal hard drives [RD series?] in the upper bay [a few MFM and power cables remain there]

BTW: The floppy drive "hidden" in the lower bay, may have a boot floppy in it. Have you checked?


In summary, depending on what you want to accomplish, you may be able to re-arrange that equipment and run the a UNIX system from the floppies, with only one of those BA23's powered. [keep the other as a spare?]

If you decide to continue disassembly, please take copious photos as you do, so we can tell where the cables go back - in case you need them. Don't pull any cards until you have complete notes on where they were, and how they were cabled in this original configuration. [photos again, are best]

Hope these hints help. Looks like the ingredients of a nice system.

Qbus
August 25th, 2011, 12:35 PM
Is that still a Qbus style system? Would assume it’s a 22 bus as opposed to a 16? What's the progression from my 11/03 and 23 to that system and finally VAX? See lots of cards on EBay that are to new for the 16 bit 23 system and too old for VAX or that’s what I assume not have ever seeing a VAX up close and always though they were 73/83 cards.

RSX11M+
August 25th, 2011, 12:57 PM
Is that still a Qbus style system? Would assume itís a 22 bus as opposed to a 16? What's the progression from my 11/03 and 23 to that system and finally VAX? See lots of cards on EBay that are to new for the 16 bit 23 system and too old for VAX or thatís what I assume not have ever seeing a VAX up close and always though they were 73/83 cards.

Yes, it's made of two BA23 boxes with Q22 backplanes [these may be decoupled and turned into independent systems if desired]

The BA23 can be used for any Qbus processor... PDP-11/02,03,23,73,83 and Micro-VAX I or II, provided power needs are met.

Cards of the generation found in original 83 systems will probably be useful in Qbus Micro-VAXs. This includes the PMI memory in the photo and many I/Os, but obviously not the CPU.

I'm not sure what you're seeing on eBay.

Qbus
August 26th, 2011, 05:32 AM
Back when I was looking for additional memory for the 23 there was always a half dozen or so "big" memory like 512, 1 and 4 meg Qbus cards listed, thatís when I found out about the difference between 16 and 22 bit address. Now that the 23 is up and running along with the RX02 and RL01 thinking I need to do a different system and maybe the 73/83 would be fun.
Still loosening sleep over the 11/23+ and four RL02 that I was too stupid to buy last spring but maybe a 73 or 83 will drive me in a new direction. Donít see any opportunity for buying a unibus system without dumping buckets of money, except maybe an 11/44

kyeakel
August 26th, 2011, 06:19 AM
Thanks for the detailed explanation RSX11M+! I hope to do this this weekend, I'll post a list of the cards. It looks like I should be able to create boot disks with one of my PC's using PUTR. Does anyone know if this will work on newer PC's, 386's or must I use an XT?

Kipp

saipan59
August 26th, 2011, 08:30 AM
As someone mentioned, the 4 smallish 10-pin connectors on the middle of the panel are for RA-series drives (RA80, RA60, etc.). It's an "SDI" bus (serial). There should be a KDA50 disk controller inside - it would be two quad-size modules (M7164 and M7165) with a very short ribbon cable connected between them, and one of the modules has cabling that goes to the "bulkhead connectors" on the I/O panel.

The M7164 module is the CPU for the controller. In the early 80's, I designed the Manufacturing Functional Test equipment for that module.

Pete

NeXT
August 26th, 2011, 09:10 AM
would you also be able to take a photo of the SDI bus cabling between the boards and bulkhead? I'm still trying to remanufacture my own bulkhead.

1ajs
August 26th, 2011, 10:25 AM
hah the card pictured in this machean is a 1mb nice and even sweater i just nabed one for 50bucks :D on ebay and a 512k witch theres still some 512ks avail if anyones looking...

kyeakel
August 26th, 2011, 01:14 PM
More pictures: Also, one of the ribbon cables that goes to the black connectors on the back panel was disconnected on both ends. It has twisted pairs on one end. Does it matter which end goes to the M7196 card? I know the location of pin one matters, there is no keying on this connector. I believe it goes to the RL01 RL02 connectors that were pointed out to me.
Cards in this system are: M8637,M8190,M7196,M7555,M8027,M7546,M9404,M9405,M3 104,M3104,M7164,M7165, and 6 M9047s. The diskette drive is not connected, I don't see any cables for it. I assume it goes to removable drive 1&2 connector in the chassis. Does anyone have cables for this or the part numbers, I'll look on e-bay.
65386539654065416542
Kipp

kyeakel
August 26th, 2011, 01:18 PM
6543654465456546
Must be a 5 picture limit....
In the picture of the power supplies (3rd pic) there are straps near the rear of each that look to have been cut off. They're fastened to pop rivets, any idea what they used to be for?
Kipp

kyeakel
August 26th, 2011, 01:20 PM
would you also be able to take a photo of the SDI bus cabling between the boards and bulkhead? I'm still trying to remanufacture my own bulkhead.
NeXT,
I'll get you some, not sure if you can see the wiring though.
Kipp

tradde
August 26th, 2011, 02:51 PM
NeXT,
I'll get you some, not sure if you can see the wiring though.
Kipp

I most likely could take a picture or two of mine in my 11/84. It has a UDA-50 though. I'd hope the cable would
be the same?

RSX11M+
August 26th, 2011, 11:43 PM
Main Box:
S1 M8637-EF [MSV11-JE 2-Mbyte ECC [PMI?] RAM Q22 Quad ABCD]
S2 M8190-AE [KDJ11-BF Q/U 11/83-84 CPU J11 CPU 18MHz with 2 boot & diagnostic ROMs, FPJ11-AA QUAD ABCD]
S3 M9047 [Q Grant continuity] ,M9047 [Same but this one shouldn't be in a CD slot??]
S4 M7196 [TSV05 tape ctl for Q/Q22 QUAD ABAB capable]
S5 M9047, M9047 [Q Grant continuity]
S6 M7555, [RQDX3 MFM Winchester and floppy disk controller DUAL] M8027, [LPV11 Q Printer Interface centronics DUAL]
S7 M9047,M9047 [Q Grant continuity]
S8 M7546 [TQK50-AA TMSCP TK50 tape ctl DUAL] ,M9404 [1st Q22 bus cable connector - CPU box AB DUAL]

2nd box:
S1 M9405, [2nd Q22 bus cable connector - remote box AB DUAL]
S2 M3104,M3104, [DHV11-A 8 line serial dual]
S3 M7164,M7165, [KDA50-Q QBUS SDI Disk Ctl - 2 bd set dual]


Ok, a correction to my previous post - There is no RLV12 ctl in this system. The two black bulkhead connectors are for the TSV05 tape ctl.
I am pretty sure the memory in box1-s1 is PMI, but my module directory isn't specific. This one has no CSR
CPU is pretty much the nicest version of the J11s. 18mhz and Has floating point accelerator installed [unless someone removed it]
Box1-S3 CD side has a bus grant continuity card. I learn something new every day, because this is not legal according to what I know.[slot should be empty] However, since it's there it MUST be harmless in this config.(??)
Although this is an 83 and contains a KDA50 [not UDA50] I think the SDI cable sets are the same pinout. I think Lou had an app note how to substitute UTP cable for these - talk to him
The floppy drive can be moved to the upper box if desired and connected via the distribution card to the RQDX3

Finally, you need a quick lesson on "BERG" style connectors and ribbons. I have a TSV05 manual to help with your other questions. [will post link]

Note: The KDA50 is a rare bird. Treat it well. It's in the second box to spread the electrical load, and I think it has to be tail-end-Charlie on the Qbus.

Not sure what else I can share. You might want to obtain a SCSI QBUS control to add SCSI disks because MFMs are getting hard to find and fragile any more. [still playing with the idea of a FLASH MFM Emulator]

There is absolutely no issue taking this system to a single box. One box can carry the memory, cpu, one DHV11, RQDX3, TQK50 and LPV11. I'd pull the other modules until you need them. It's best to leave the boxes ganged physically, so the rear cover works, but the other box can be unplugged from AC. [I see no power sequencer in use]

Do you have a 19" equipment rack for it? If not this would be a wise purchase.

Let us know what else we can help with.

jackrubin
August 27th, 2011, 03:37 AM
And once again, there is a small batch of CMD CQD-220A/E SCSI controllers on eBay at $150 each, a great price - 260842492333 .

kyeakel
August 27th, 2011, 05:35 AM
Wow, thanks for all the great info. I'm going to power it up this weekend, after that I'll buy an MFM drive or SCSI setup. I'm on the lookout for a 19" rack as well. Is there a certain size MFM drive this needs? Will any MFM drive work?
Kipp

Lou - N2MIY
August 27th, 2011, 06:20 AM
Indeed this is a beautiful machine!

Although this machine has an RQDX3 in it, I'd only keep it there as a controller for the RX33 floppy drives. I am sure that the real mass storage was connected to the KDA50. SDI works very well, and is much much faster than an MFM hard disk. In my 11/73 I have an RQDX3 with RD31 drives attatched and a KDA50 with an RA72. The RA drive is much much faster.

There is an RA72 on ebay right now BIN for $95. That's the right drive for this 11/83!

I can provide help on SDI drive cabling, but I'm on the road at the moment. I'll be a little more useful next week. Yes, you can make your own SDI cabling with four-pair UTP (etherenet cable). In a pinch though, you can unplug the SDI cable from the bulkhead and plug it directly into the back of the RA7X drive. The rule is, for real DEC SDI cables, there must be an odd number of cables from the back of the controller to the drive. This is because the bulkheads cause crossing over of the lines.

I agree that the grant continuity card in the CD of slot 3 is not necessary. That's the last PMI slot.

I however, do like the two BA23 arrangement here. The KDA50 is renowned as a huge power supply load. It would be good to keep in the second BA23, since each BA23 has its own power supply. You can use the second BA23 also to power the RA72 mentioned above.

As a parting thought, the upper chassis clearly has room for the RA72 on the left and two RX33s on the right. The RX50 can be put on a shelf somewhere. That's what I'd put in this system!

Lou

VintageComputerman
August 27th, 2011, 07:40 AM
Anyone see the PDP-8 that just sold on ebay for $8,100.00? Item # 230660204770

kyeakel
August 28th, 2011, 08:19 AM
Indeed this is a beautiful machine!

Although this machine has an RQDX3 in it, I'd only keep it there as a controller for the RX33 floppy drives. I am sure that the real mass storage was connected to the KDA50. SDI works very well, and is much much faster than an MFM hard disk. In my 11/73 I have an RQDX3 with RD31 drives attatched and a KDA50 with an RA72. The RA drive is much much faster.

There is an RA72 on ebay right now BIN for $95. That's the right drive for this 11/83!

I can provide help on SDI drive cabling, but I'm on the road at the moment. I'll be a little more useful next week. Yes, you can make your own SDI cabling with four-pair UTP (etherenet cable). In a pinch though, you can unplug the SDI cable from the bulkhead and plug it directly into the back of the RA7X drive. The rule is, for real DEC SDI cables, there must be an odd number of cables from the back of the controller to the drive. This is because the bulkheads cause crossing over of the lines.

I agree that the grant continuity card in the CD of slot 3 is not necessary. That's the last PMI slot.

I however, do like the two BA23 arrangement here. The KDA50 is renowned as a huge power supply load. It would be good to keep in the second BA23, since each BA23 has its own power supply. You can use the second BA23 also to power the RA72 mentioned above.

As a parting thought, the upper chassis clearly has room for the RA72 on the left and two RX33s on the right. The RX50 can be put on a shelf somewhere. That's what I'd put in this system!

Lou

Lou,
Sounds like a winner. I bought one of the RA72's, and look forward to discussing it with you when you have time.
Kipp

NeXT
August 28th, 2011, 09:12 AM
Actually scratch that. I can't confirm which controller I have again and I can't easily reach it because my /84 is currently at the bottom of a rack-less stack. It amazes me just how much people want for scrap racks.

kyeakel
August 28th, 2011, 10:08 AM
Here is where I'm at thus far. I've reassembled the unit, and powered it up. Upon power up I get the LEDs as noted in the picture of my notes.
I tried 2 terminals connected to what I think is the console port. The baud rate stays at 2400 (7-segment displays indicate a "4"). If I use a null modem adapter, I get some funky characters scrolling across the screeen on my H19. The H19 is set for 9600 baud, I'd have to dig out the manuals to change it. There is a knob next to the baud indicator on the PDP that I think should change the PDP rate, but turning it does nothing.

6559

kyeakel
August 28th, 2011, 05:10 PM
After some further playing, I see that the 7-segment display has nothing to do with the baud rate. I was at a bad angle and did not see the little digit above the knob. Once I got it set to 9600 baud, it came right up. I get: testing: please wait, and it counts 1-9. After some time, I got impatient, and pressed ESC, which cleared the screen and it came back with: waiting for boot disk or drive ready. So, once I get cables for the floppy, and a boot diskette, I should be able to move forward.
Thanks All!
Kipp

RSX11M+
August 28th, 2011, 06:59 PM
Hi Kipp,

Glad you stumbled your way to success.

This KDJ11-B (http://scandocs.trailing-edge.com/micropdp11-volume1_system_cpus-EK-247AA-MG-001.pdf) manual may be of help... [download the full PDF at that link]

If I were you, I would set the system to go to dialog mode on boot. You can then set the defaults for various boot devices using the menu system. You'll be off and running in no time.

You might want to keep the Maintenance manual for the BA23 (http://www.retrocomputingtasmania.com/members/nw-retrocomputingtasmania-com/pdp-11-93/BA23EnclosureMaintenanceEK-186AA-MG-001.pdf?attredirects=0) as a reference too.

kyeakel
August 31st, 2011, 05:23 PM
The manuals were a good read. I've been into the setup menus, all looks good.
I also read Lou's posts on the homemade SDI cable. If I can get the pinout, I'll make my own CAT-5 cable. I'm pretty sure I have the connectors already.
Kipp

NeXT
August 31st, 2011, 08:33 PM
Indeed this is a beautiful machine!

I can provide help on SDI drive cabling, but I'm on the road at the moment. I'll be a little more useful next week. Yes, you can make your own SDI cabling with four-pair UTP (etherenet cable). In a pinch though, you can unplug the SDI cable from the bulkhead and plug it directly into the back of the RA7X drive. The rule is, for real DEC SDI cables, there must be an odd number of cables from the back of the controller to the drive. This is because the bulkheads cause crossing over of the lines.

Lou

what?
I was told that they required 96 ohm cabling and ended up having to make my own cables and bulkheads from scratch. Do not tell me I took the long route.

Lou - N2MIY
September 1st, 2011, 04:43 AM
Well,

Here is the original thread on my DIY SDI cable work. You will see that the very last post documents a realization I had after first building a cable from small diameter coax.

UTP has an impedance of about 100 ohms. The coax that I first used was 75 ohm baby coax from VGA monitor cords. The real SDI cable is 93 ohm impedance. HOWEVER, the end connections are like Berg connectors and are likely not well matched to the impedance of the cables. So, for shorter runs (like home use) the cable impedance can't be that important. The cat 5 four pair UTP is actually closer in impedance than the 75 ohm coax I used.

It's also worth mentioning that the SDI hardware uses the cable in a balanced fashion, making UTP all the more acceptable for this application.

Lou



what?
I was told that they required 96 ohm cabling and ended up having to make my own cables and bulkheads from scratch. Do not tell me I took the long route.

kyeakel
September 1st, 2011, 04:52 AM
This sounds easy but I did not see the pinout listed in the original thread. Can you point me to it?
Kipp

Lou - N2MIY
September 1st, 2011, 04:12 PM
I'm sorry about that! Duh! I meant to paste in the link to the earlier thread. Here it is : http://www.vintage-computer.com/vcforum/showthread.php?18049-DIY-SDI-Cables

Also, the pinout will be useful as well. If you can hang in there a few more days, I'll make and post a sketch over the weekend. I figured it out by looking at the prints for the UDA50 and RA80. If you're in a hurry, you can do that yourself, or I'll be near the cable again Sunday to make a nice sketch (which I will do anyway) and post it.

Lou