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I'M Back, PDP 11/40..

Marty

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Jul 26, 2009
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Hi All;
AL, Send me an Email Address, where I can send them to You, Via Personal Message.. And I'LL get them to You..
I had my own Print Set to help me, so when one was not so good the other one was most of the time better.. Even though I tried going off of Your Print Set, because I could Enlarge more, I used mine just as often..
I have found out that from others that I sent them to, that they are not very Dark, because of them being in Pencil, (I will need to look into if it is possible to make then files Darker..) And I hope to SomeDay transfer the Information to something that will Print better, like Open Office..
Also, remember, that they are Only to one Ic per Board type, I have not listed all connections to every Ic per Board..
THANK YOU Marty
 

Marty

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Hi All;
Compared to What it was before, it looks like the Damage is minimal, so far, I have all the Boards back in and nothing is over heating at the present.. The big Difference is I can't get the Address lights to display and the Maintenance Board won't increment the PuPP's or Bupp's, I am looking at the Timing Board and seeing what may be holding things up..
THANK YOU marty
 

Marty

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Messages
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Hi All;
I just found a good way to check, at least page 2 of the Timing Module page, My Scope has a 1000 Hz clock for testing probes, and so I clipped it to J1 the Input for DL2, and switched it to that test point.. Many of the Leds on the Maintenance Board are now going Nuts, which I fine.. Anyway I can check a good Deal of the IC's on that page, possibly other pages, as well.. It also shows all of the Data Leds are now On, so that proves that they all at least come on..
After, pressing the (Manual Mclk button, (on the Maintance Board) I got it to to go into a funny Infinite Loop, So I can now say All the Address Leds work, as well as the Run, Bus, and sometimes Console Leds, on a previous running the Processor Led would also work.. So I know that All the Front Panel Leds work, except Virtual and User, and I am not saying that they do not work, they just don't light at this time.. Its Funny Watching it go thru its round of Repeating and turning things on and off.. So, it would seem like its Partially there.. Just need to find where its not right or correct.. The other thing is How nice and Clean the Signals look on the Timing Board, using this Square Wave from the Scope, compared to the very Rounded and Ringing that I would otherwise see, when using its internal signals, for the clock..
THANK YOU Marty
 
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Marty

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Boulder , Colorado USA
Hi All;
I got it to single step, I can't say I have done really anything since my last posting.. I added two more Leds to my Maintenance Board, so that the two slide position switches that now show what is really happening.. All of my Leds show thru a driver what is happening at the bus level.. I have adjusted the delay time switch, and I think that mostly got it back to working.. Right now the Console Led goes on and off and the Run led does the same thing, so at least I know they are working..
Right now it is back to the scope frequency, where I am going to next check out the Data Path Board, And just do some looking around and see If I can locate, where or if the Hangup is there..
THANK YOU Marty
 

Marty

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Jul 26, 2009
Messages
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Location
Boulder , Colorado USA
Hi All;
I am going to have to Re-Wire and Replace some of the Components on the Maintenance Board, The problem seems to be two fold..
First, there isn't enough Room on the Board for what I want, so I will eliminate some things and add others.. Also, it might be too much for the Signal Lines to Drive two TTL Loads, So I am changing some of the circuit.. It will be for the better..
Also, I Found my old Wire-Wrap Tripple Quad Board Which will be cables to another Board where I am going to make a Manual U Word Board, it will have the ability to display What address the Roms are being addressed and also then 56 switches for the Rom Output.. That way I can Simulate any combination and Or Check any single Rom output Via a Switch.. And check where the signal Goes and what it affects, what gets turned On or Off and How that affects that particular Logic, what Ever Board it goes to.. I am seeing Some funny reading from the Maintenance Board, and even without the Maintenance Board, it still doesn't act right.. This way I can Trace Each of the 56 Bits and see what they really do.. And I also will be able to Check out the Maintenance Board, since it displays PUPP and BUPP which come from the U Word Board, which it is being faked into thinking it is seeing.. So, this will be what I hope to do next week, as it is Late and No more tonight..
THANK YOU Marty
 

RSX11M+

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Since you're going to that trouble... is there a particular reason you put the components on the back side of the module? Maybe you had a good reason. Customarily, they'd be on the other side [matching other originals]. You can see good examples of this technique in Lou's PDP-8 Album.

Troubleshooting modules I've done have displays and controls on the top card edge. Clip points for scope probes too - Gnd, +5v, some bus signals. Done this way, it could be kept in your chassis - ready in case of unexpected trouble.

Just thought I'd offer comment before you re-did it again. Give you time to think it over.
 

Marty

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HI All;
RSX11M, When I first made the Maintenance Module I thought the IC's were on Top and the Pins on the Bottom of the Board.. Like all other Wire-Wrap Boards that I've seen and done.. Even on my one Official Dec Board it is done that way, a W9301.. Is that what You are referring to ?? Or
Are You talking about the General Layout of the Components, Mainly that was that way as I added stuff to the Board..
The Numerical Led displays were an after thought..
I am taking all but one of the 10 segment Bars off of the board and putting in the Numerical Display in its place.. And Re-arranging where all of the components are going to be.. Now there are some restrictions, because, I already put certain size sockets in some places and since in the middle two rows it is NOT drilled for continuous sockets but for 14-16 pin sockets, like the two outside rows which are continuous.. I wish all of the rows were continuous sockets.. There is really not much room at the top of the Card because of the way it is drilled out..
If there IS a Pin on the Bottom that is Really not used, I am going to bring up more signal(s) to the card.. I know of one on the E side and all of the F side is blank.. And remember all of my Chassis are wooden, except for the PDP 11/04.. But I don't know If the Maintenance card is wired for that chassis.. I don't think so, but sometime I need to check.. I think the Maintenance Card is for the PDP 11/40 and PDP 11/45 that I have.. I have Not built a wooden enclosure for the PDP 11/45, it is still in sort of storage until I get the PDP 11/40 done or as far as I want or can get with it..
THANK YOU Marty
 

pbirkel@gmail.com

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Silver Spring, MD, USA
I believe that his point was that the chips/sockets belong on the side of the board towards which the handles face/protrude. That's the side that is "spaced out" on all DEC-standard modules. The WW pins go on the opposite side and necessarily they require that the following slot be empty since standard 3-wrap pins are just-that-long. Normally that side just has the component soldered "nubbins" so a module can go into the next slot.
 

Marty

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Hi All;
I had never before seen that type of Wire-Wrap Board before, and since I don't have the means to unsolder the sockets and put them on the other side.. They will just have to be that way, and I can live with it.. For the present there is nothing behind the board..
Here are some picture of the latest layout of the Maintenance Board, nothing is wired as of yet..
11242013873.jpg 11242013874.jpg 11242013875.jpg
THANK YOU Marty
 

RSX11M+

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Not having the means to unsolder the sockets is the clincher. Better not to try at this point. I didn't notice the absence of a usable field of holes or strip of positions along the top. [bad assumption on my part] You can see this pattern on Lou's boards, just to illustrate the point.

Yes, the customary technique for DEC modules is Components, Sockets, Pins and wraps all on the "Top" side of the board. The "Bottom" side is trimmed flush.

Last night I gave a quick look for the style of display used in my boards and realized they were hard to find, if not unavailable.

So the entire suggestion is a bust. Perhaps you can use some of it in future.
 

Al Kossow

Documentation Wizard
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Yes, the customary technique for DEC modules is Components, Sockets, Pins and wraps all on the "Top" side of the board. The "Bottom" side is trimmed flush.

That was done so that the prototyping modules only required one slot space.

Wiring on the bottom side lets you run point-point instead of in 'channels' between
the ICs, which minimizes long parallel wire runs. It's also easier to get a DIP clip
connected if there aren't wire-wrap pins next to the socket.

As you noticed, DEC was one of the only companies that sold prototyping cards that
expected wire runs on the component side.
 

RSX11M+

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Yep, all true.

In other bus and manufacturer's systems, components on one side, wraps on the other was predominantly the style. I only saw a few DEC engineering or field service special purpose boards done in that manner. By the latter PDP-11 era, anything meant for even limited production or customer use was usually the other way. As I recall, we used some MDB prototyping cards, and they followed suit too. I really came to appreciate those - already stuffed with common bus interface chips.

I've done both styles myself. Somehow it always seemed worth the extra effort and planning to follow this technique for DEC modules. Perhaps it's a personal thing. Certainly it's not worth making a fuss over. Reasons outweigh preference any day.

As to accessibility - I suppose it all depends on your tooling and other factors. I just stick an extender card in when I need troubleshooting access. The problem I most regret, when it happens, is not having the card already in the backplane when things happen. Bus hangs for example... much easier to diagnose if your tooling is already there.

DEC service had a really cool UNIBUS trace module they left in our 11/70 for a while, in an attempt to locate such a problem. I seriously considered cloning it and leaving it there full time - it was so valuable. Still have the schematics to do so.

Doing prototypes with a card that takes 2 slots, one unnecessarily - is sometimes too painful to contemplate.

I'm not sure my experience with DIP CLIPs on these types is in concurrence with yours. Putting DIP clips on socketed ICs is a precarious practice at best. In DEC modules that are standing vertically - it's worse. Gravity tends to pry the chip out, from the weight of probes and the CLIP. I actually like having the wrap post nearby to attach probes to. Another advantage is that it's component side - so there's no reversal that needs to be accounted for when working from the wrap side in other styles. [you don't have this problem with DIP clips either]

Good discussion.
 
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DaveH

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I find that even the humble 16 leds on a clip, TTL Logic checker, can be very handy. Iv also just made a new overlay for the maintance panel for the RX01 so its the correct way up !, much easier to use now.
Dave
 

Marty

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Hi All;
Thank You all for the information.. I had never seen this style before.. So, I was unaware of my doing it backwards..
I plan on getting an Extender Card that will be just for the Maintenance Board, so it won't be any problem, which way the Pins are facing..
I have two of the 16 pin Led Clips, but Both of them have broken, the little plastic piece that connects the two side together and is used as a kind of a hinge, I tried to glue one together, but the glue doesn't hold..
THANK YOU Marty
 

RSX11M+

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...I was unaware of my doing it backwards...
Wooooaaaa there Tex.. I never meant to imply that! And I'm sorry if it came out that way.

If anything, the DEC methodology is the one that's "Backwards" - reversed from the defacto "Standard". I was merely trying to acquaint you with the fact of, and attributes attendant to - DEC's "Customary" way.

Never did I mean to impune your work sir.
 

Marty

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Hi All;
RSX11M, stated :
" Wooooaaaa there Tex.. I never meant to imply that! And I'm sorry if it came out that way.

If anything, the DEC methodology is the one that's "Backwards" - reversed from the defacto "Standard". I was merely trying to acquaint you with the fact of, and attributes attendant to - DEC's "Customary" way.

Never did I mean to impune your work sir. "

NO Offense was taken , nor thought of as Implied, I was merely stating my ignorance of same, Since I am not very DEC related up on the ways or their standards.. Actually, I am Glad to have that and other things pointed out to me about the proper way , I can then do better later and remember What is the correct way and sometimes easier way to do things..
Also, others who are "NEW" to the Hobby can also benefit and or Gain on the insight..
So, THANK YOU for the insight and keep it up.. I need "more input" from all of you experts.. Especially related to my machines and the feeding and caring for them.. As well as the Maintenance and troubleshooting of them.. Keep up the good work !!!!
THANK YOU Marty
 

pbirkel@gmail.com

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Silver Spring, MD, USA
DEC service had a really cool UNIBUS trace module they left in our 11/70 for a while, in an attempt to locate such a problem. I seriously considered cloning it and leaving it there full time - it was so valuable. Still have the schematics to do so.

Could you share them? Would be quite educational :->!

(Also, does "DEC up" style actually support a full three wire-wraps -- or do you have to go-short on the third? Using headers a la Lou would definitely leave you short, although after soldering I s'pose you could pry off the header-plastic to gain wrap-length?)
 

Marty

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Hi All;
I have laid out the Layout of the U WORD Module, And hopefully this will be close to the end product.. I have tried to take some pictures, BUT they are ALL Out of Focus, I have tried Indoors two different places and Outdoors.. No difference.. So here are some Blurry Pictures of it..
11252013883.jpg 11252013886.jpg 11252013890.jpg
And Oh, Yes, I believe in LOTS of Led's.. The more the merrier..
THANK YOU Marty
 
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