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So I got my first PDP-11

Ioncannon

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Some of you may remember a while back I was interested in a PDP 11. Almost got a 11/34 but the guy scrapped it before I could get it. While browsing ebay, I so happened to find a 11/04 with 4h remaining. Sniped it at the end (sorry to the two other bidders who were fighting each other) and won it for $430. I think that is the most I have ever payed for a vintage computer.

Here is the auction: http://www.ebay.ca/itm/300671695440?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648

So, the computer itself seems in a dirty mess. Sadly it doesn't have the programmer's console, however I read up that it should have an emulated one. Only thing I am worried about is that he didn't list a M9132 card.

Trying to find information on how the system is powered. It needs a power supply correct? It's not like you have an A/C cord at the back. Won't be able to know for sure until it arrives, but what other things do I need to get it into running order?
 

Lou - N2MIY

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My friend, you actually have an 11/24! From the card list, it has an 11/24 processor and a 128kW memory.

This chassis should indeed have a place for a line cord at the back.

It does not look too dirty to me. It should not be too hard to get this running.

The card list also lists an M7628, which I have no idea what that is. Likely it is an M7268, which is part of an RK11 (RK05 controller).

What do you have for mass storage otherwise? If nothing, you can at least connect a PC and run an emulated TU58.

So, it looks like a nice little machine to me.

Just curious, but are you in Canada?

Lou
 

Ioncannon

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My friend, you actually have an 11/24! From the card list, it has an 11/24 processor and a 128kW memory.

This chassis should indeed have a place for a line cord at the back.

It does not look too dirty to me. It should not be too hard to get this running.

The card list also lists an M7628, which I have no idea what that is. Likely it is an M7268, which is part of an RK11 (RK05 controller).

What do you have for mass storage otherwise? If nothing, you can at least connect a PC and run an emulated TU58.

So, it looks like a nice little machine to me.

Just curious, but are you in Canada?

Lou

This was also confusing me, since when I looked up the boards, I read the cpu boards were for a 11/24 not 11/04. Was this an 11/04 with 11/24 boards put in (can that be done?)? Why would the console be a 04 or 34 operator panel? The board is probably a M7268 since he also had a RK05 for sale. Currently I do not (maybe one day, but right now my funds got depleted lol), is hooking up a serial cable difficult? And yes I am in Canada.

Regardless what model, I can't wait for it to arrive.

Edit: You probably know more, but I just remembered I was checking if the top board was the CPU board and compared pictures.

Maybe it was a mislabel, but if you look at these two boards and the pic on Ebay, it matches with the 11/04.

http://hampage.hu/pdp-11/kepek/11-24c_1.jpg (PDP-11/24)

http://ummr.altervista.org/images/DSCN5614.JPG (PDP-11/04)
 
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Lou - N2MIY

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Yes, I am pretty sure this machine was "upgraded" to an 11/24. Actuallt 11/04 to 11/24 would be an upgrade, but I would not call 11/34 to 11/24 an upgrade. So, most likely, this really did start life as an 11/04. I have both processor boards here and know what they look like.

The serial cable is easy. We need to figure out where it was connected though. The 11/24 processor can locally drive two SLUs, but this machine also has a separate SLU card in it (most likely the one used when it was originally an 11/04. I would try that one first (the one on the separate SLU board). The pinout for the cable is in the DL11-W print set, as well as various other places. The right cable is a BC03L and I have made my own.

Actually rather than "trying" anything, the right thing to do is study how every board is configured. You will be taking this entire thing apart to clean it anyway. You'll also be first firing it up with all boards removed to check the power supply voltages.

Where to connect the second SLU for the TU58 will be interesting. I would think through one of the SLUs on the 11/24 processor board. Although I have some 11/24 processors, I have never used them. I too have a real 11/04 and have thought about trying the 11/24 processors, but I would likely disable the on-board SLUs and just keep using the two DL11-Ws I have configured as the console and for the TU58.

It's a shame you don't have money for the RK05. Good luck finding one of them again, but then the packs are hard to find too. I personally like the RL drives better. Get some of those, and swap the RK11 with someone for an RL11.

Let us know when it arrives. In the mean time accumulate and study all the manuals and print sets off the internet.

Lou

P.S. ??? Was this the 11/24 that Ray was talking about in the last thread ???
 

Qbus

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Yea, that’s the one I was bidding on but I dropped out at $370, being I all ready have an 11/23 just did not have that much of an appetite! System has a mix of 04/24 cards and I thought the thing to do would be remove the second SLU and old memory to maybe decrease the load on the power supply. System also has a lot of real time cards for something. Myself I would start just running the CPU, one memory card and maybe invest in a bootstrap terminator card. Good thing is if it truly is just a repackaged LSI system testing and operation should be simple. Take a look at this web site: http://www.bitsavers.org/pdf/dec/pdp11/ and you will find manuals and schematics for the both the 11/04 and 24, after cleaning and testing the power supplies then work on building the serial cable and then you can then examine and load memory in octal and almost every manual has a little ten or twelve line program you can load that test the system.
Next thing to look for is a RX floppy or RL hard drive that system will look good racked up with all that.
RF
 

Ioncannon

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Yea, that’s the one I was bidding on but I dropped out at $370, being I all ready have an 11/23 just did not have that much of an appetite! System has a mix of 04/24 cards and I thought the thing to do would be remove the second SLU and old memory to maybe decrease the load on the power supply. System also has a lot of real time cards for something. Myself I would start just running the CPU, one memory card and maybe invest in a bootstrap terminator card. Good thing is if it truly is just a repackaged LSI system testing and operation should be simple. Take a look at this web site: http://www.bitsavers.org/pdf/dec/pdp11/ and you will find manuals and schematics for the both the 11/04 and 24, after cleaning and testing the power supplies then work on building the serial cable and then you can then examine and load memory in octal and almost every manual has a little ten or twelve line program you can load that test the system.
Next thing to look for is a RX floppy or RL hard drive that system will look good racked up with all that.
RF

Heh, I was watching the two of you fight and was worried how high the price would get. I find bidding before the last minute counter productive, it just raises the price. I actually put the bid a $450 at 5 seconds and hoped the other guy wouldn't react in time.

The first thing I will do is definitely take it apart and clean it out. Seems the whole thing is really dusty and dirty. The next thing would be testing the power supplies, especially since I heard the like to die out a lot.

I plan to attach an RX and RL drive to the system in the future and maybe put Unix on it. Were all the peripherals compatible with the various PDP-11s? One thing I would really like to get is a PC05, just because loading with paper tape is so cool!

How expensive and difficult to find are PDP cabinets? Preferably a full size one!
 

Qbus

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The big power supplies appear to be Fairley durable. I disassembled both power supplies in my 11 and expansion cabinet and other then being dirty found no issues with them. Watch out for the condition of the plastic on the Molex connectors because that stuff is getting so old its brittle lots of times. The big item on the power supplies may be replacing the fans if they are bad. If you do check the voltage on them first. I did have to repair a H780 for my little 11 system but if you have worked with switching supplies before they are no big deal. Just about any nineteen inch rack works as long as it has both front and back rails and wheels are a big benefit. I run RT-11 and find that to be a real easy to work with operating system once you learn the drive designations and command syntax, but if I can do it anyone can.
 

Lou - N2MIY

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I'm with Ray on RT-11. It's the best for getting started and even for getting real work done in a single user environment. There is also plenty of software out there to keep one amused. Personally, a basic language interpreter is enough to keep me amused.

The perhiperals are all basically interchangeable. The controllers though are different between qbus and unibus, as you know. As an extreme example, I have connected a dual ported RA80 disk drive to the 11/04 (unibus UDA50) on one port and an 11/53 (qbus KDA50) on the other port.

Real dec racks are not always easy to find anymore. It depends where you live. Where I am, other locals who are better connected than I will get them first. But, any 19" rack will work, and I have contemplated making one out of 2x4s (lumber).

So, now keep your eyes out on ebay for that RX211 and RL11 you will want eventually...

Lou
 

Ioncannon

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So, the pdp-11 has arrived. ****ing UPS and their "brokerage fees" charged me $125 :(. Anyway, I still have yet to open the box with all the boards in it, but the chassis looks... er ok. Has a bit of rust here and there, and is a bit dirty. Will post up some pics soon. Also the front panel seems to have been warped in an accident sadly. At the bottom is warped slightly, and caused two of the "pillars" to crack (but still hold together). Well, can't complain for a 30 year old computer. I was going to replace the operator panel anyway!

What should be the first steps to testing the power supply? There are two cables that seem to be chassis grounds... they aren't connected.

Never-mind, found out from a maintenance manual they are for the front panel. Next, I have this grating thing that seems to have belong to the front panel, but it doesn't attach to anything. Anyone know what it belongs to?
 
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Lorne

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So, the pdp-11 has arrived. ****ing UPS and their "brokerage fees" charged me $125 :(.

NEVER pay those brokerage fees if you live close to a major city.
It's a real scam by the brokerage firms.
When I lived in Vancouver, I'd get their fee, and say no thanks, I'll clear it myself.
I'd drive to the customs and duties office at the airport, and usually clear the stuff with no fee at all, and certainly with no brokerage fee.
It's a real rip - what you end up having to pay $ 3.45 in duties for, they'll try to charge to $ 60.
 

Ioncannon

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So took a look at the boards, cpu is a M7263, so it is the /04 cpu. Just checked, also has the /24 cpu too! Other boards are

M7856 DL11-W U RS-232 SLU & realtime clock option (Has a Depot Material Control Tag on it)
M7856 DL11-W U RS-232 SLU & realtime clock option
M7228 KW11-P U Real time programmable clock
M7891

And a unmarked board....

Trying to figure out what this cable that goes from the front to the back of the chassis is. Has three prongs (Red/Black/Grey) at the back, and two (black/red) at the front. Also a green wire which looks like a chassis ground.
 
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Ioncannon

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Did you download any of the books yet? Epically the two at: http://www.bitsavers.org/pdf/dec/pdp11/1124/
The manuals are not exactly the same but close enough that you will find the layout for the chassis and the wiring along with everything for the power supply.

Just checked the engineer drawings for the /04. It's exactly what I needed. Was trying to looking in the user manuals but they don't cover wiring much. Thanks!

Figured out what it was for. The Grey/Red/Black wires hook into a M9312, and the other side goes into the front panel. The green wire is grounded onto the front panel.
 
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Qbus

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The technical manual for the 11/24 is there too. The end of the second chapter and beginning of the third have some useful information on system testing and using the ODT. Don’t know if it works on a 24 but I used this a lot with the 23 loaded from the con, the greater minds on the list can tell me if I am in error because the Ubus systems have different addresses or not. I am assuming that because it uses a LSI CPU it’s the same thing but what do I know.

1000 005000
1002 12701
1004 177564
1006 105711
1010 100376
1012 110061
1014 2
1016 005200
1020 000137
1022 001006

Then type 1000G

Put up some pictures!
 

Ioncannon

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The technical manual for the 11/24 is there too. The end of the second chapter and beginning of the third have some useful information on system testing and using the ODT. Don’t know if it works on a 24 but I used this a lot with the 23 loaded from the con, the greater minds on the list can tell me if I am in error because the Ubus systems have different addresses or not. I am assuming that because it uses a LSI CPU it’s the same thing but what do I know.

1000 005000
1002 12701
1004 177564
1006 105711
1010 100376
1012 110061
1014 2
1016 005200
1020 000137
1022 001006

Then type 1000G

Put up some pictures!

Got a chance to test the power supply outside.... no smoke! Now that I can see it in daylight, it is pretty messy. Going to clean out the inside of the psu, and thourghly the chassis. Voltages check out, didn't get to look them up under a scope yet.

Will post pictures soon!

I am missing the M9312... since I don't have a programmer's console, is there no way to test/debug the pdp?
 
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Qbus

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I would disassemble everything as far down as your comfortable with. The fronts are easily removable and if you take the local control off you can wash that white panel in a sink with soap and water. The frame will clean up with a wire brush and its way easier to just trash the muffin fans and replace them with new ones then bother with trying to clean them. The power supply has to be opened as far as you can get it and all the dirt and dust removed, I use a paint brush and shop vacuum for that stuff. This also gives you opportunity to see if anything appears to look wrong and maybe check all the filter capacitors and diodes before applying power.
I thought the CPU cards had two SLU ports on them? Got to have a SLU to use ODT, not much will happen until you can get to the con. Maybe someone on the list can spot you a SLU, Qbus serial interfaces are plentiful and cheap but don’t know about Unibus interfaces.
That’s a great old system and like the case style although it looks very Qbus. Think if you're going to do a Unibus system and cannot get one of the big money light and switch systems that’s the way to go as opposed to the larger 11/44 and such, If I had the older 04 CPU and the small core memory myself would build up a 11/04 system and try to keep it as primitive as possible.
 

Ioncannon

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I would disassemble everything as far down as your comfortable with. The fronts are easily removable and if you take the local control off you can wash that white panel in a sink with soap and water. The frame will clean up with a wire brush and its way easier to just trash the muffin fans and replace them with new ones then bother with trying to clean them. The power supply has to be opened as far as you can get it and all the dirt and dust removed, I use a paint brush and shop vacuum for that stuff. This also gives you opportunity to see if anything appears to look wrong and maybe check all the filter capacitors and diodes before applying power.
I thought the CPU cards had two SLU ports on them? Got to have a SLU to use ODT, not much will happen until you can get to the con. Maybe someone on the list can spot you a SLU, Qbus serial interfaces are plentiful and cheap but don’t know about Unibus interfaces.
That’s a great old system and like the case style although it looks very Qbus. Think if you're going to do a Unibus system and cannot get one of the big money light and switch systems that’s the way to go as opposed to the larger 11/44 and such, If I had the older 04 CPU and the small core memory myself would build up a 11/04 system and try to keep it as primitive as possible.

I was trying to remove the power supply, but got stuck. The wires from the fan to the powersupply go through a small hole. How do I get them through without cutting them? I prefer the blinking lights too, but don't mind the 7segment + keypad, once I get a programmer's console. The later ones are boring lol. Along with cleaning and rust removing, I will need to replace all the missing nuts and bolts. Do you know what those two pieces of metal are at the last picture?
 

Lou - N2MIY

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The 11/24 does indeed have two SLUs on it, however they are wired out through fingers on slots E and F. They do not appear to be disableable by any jumpers on the 11/24 processor board. So, I suspect that the three random looking individual conductors hanging out of the backplane are wrapped to the first SLU.

Just unplug the fan wires from the fan. They might be soldered on, but then desolder them from the fan terminals. You should also download the 11/04 print set (MP00019), since it shows this case and how it all goes together, including the power supply.

I am not sure what those two pieces of metal are, but you should find them in the print set. Did you get the big sleeve like cover that goes over this chassis?

Lou
 
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