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PDP 11/45, Part 5

Hi All;

Thank You Dave for Your words of praise.. I don't deserve it..

How is Your 11/45 coming along ??

I got the Tester to work as I expected it to work, After I set the appropriate switches up, so that I can test a certain IC or multiple IC's I can put a signal on the Input Gate and see a result on the Led's..
Yes, it is slow, but it does what I wanted and what I needed for it to do..
So, I am Happy with it.. There are still some additions and possible changes that I will want to do to it, but for Now it is OK..

I found another Bad IC, it's another 74153.. Replaced it, it doesn't look like much difference, So I will keep on Looking for more problem IC's..
That IC wasn't Bad after all, I forgot that the signal was inverted on the Buss.. All of the other 74153's were OK..

I have changed to the other Board, where I can check out the same signals as which are on the SJB Board and plugs into the same slot..

In the M8107, I have found a weak 8881 when I put a 7439 on top of it, then it works OK, so trying to drive multiple boards it most likely won't have enough oumph to do the job..


THANk YOU Marty
 
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Marty, Don, Dave and anyone else,

At one point Marty had indicated that several 11/70 boards were interchangeable with "equivalent" 11/45 boards. I see that a number of the 11/45 M810x cards map to 11/70 M813x cards but with the note that they are "modified". Could someone please elaborate on the modifications made. Can the 11/70 boards be swapped in for 11/45 cards?

Thanks,
Jack
 
Hi All;

Jack, only a few of the Boards are interchangeable..
The M8134, M8135, and the M8136 are Not Interchangeable..

The M8130 Data Paths With a circuit modification, adding One IC and rewiring and cutting some lines, can then be made into an M8100..
On the M8101, the M8102 and the M8103, the M8131, the M8132, and the M8133 can be switched with this one caveat that is depending on whether the machine is an early or late 11/45 and only (I think) early 11/70 Boards.. On these Boards It is on a try it and see type of situation..
I have some boards that at present don't work, BUT, I do not know if that is because they are Later Boards OR if it is just that it is a Non-working board.. Only as I can sometime in the future test them on my Tester and Compare finger/traces between various versions..
These are the Only Boards that are exchangeable at present..
I think I can make the M8139 Timing Board work, BUT, that would be with Extensive Modification, and at present I have Lost mine and so I can not do any more work on it, until I find it again..

I hope this Helps some..

THANK YOU Marty
 
When I cross-walked various DEC FMPS and manuals a year or two ago I found a more complicated situation than Marty describes. Ignoring the potential for module modification that Marty outlines for the M8130 (and regarding which I have no comment), there are only a very few cases where DEC identified a given module as working in more than one CPU configuration between these two families -- which together include four different CPUs.

The 11/70 includes the KB11-B and KB11-C. Ignoring FPU differences (slots 2 through 5), these use the same module set in slots 6 through 22 except in three cases:

- KB11-B uses the M8132 IR Decode & Condition Codes (IRC) in slot 9 whereas the KB11-C uses the M8132 "CS REV. B or higher"
- KB11-B uses the M8133 ROM and ADDR Control (RAC) in slot 9 whereas the KB11-C uses the M8123
- KB11-B uses the M8138 System Status Registers (SSR) in slot 15 whereas the KB11-C uses the M8138-YA

The 11/45-50 is the KB11-A and the 11/55 is the KB11-D. Ignoring memory and FPU differences, these use the same module set in slots 6 through 15 except in four cases:

- KB11-A uses the M8102 IR Decode & Condition Codes (IRC) in slot 8 whereas the KB11-D uses the M8132 -- same as for KB11-B and possibly KB11-C
- KB11-A uses the M8103 ROM and ADDR Control (RAC) in slot 9 whereas the KB11-D uses the M8123 -- only the latter being the same as for the KB11-C
- KB11-A uses the M8106 Unibus and Console Control (UBC) in slot 12 whereas the KB11-D uses the M8119 -- there is no sharing with either the KB11-B or KB11-C
- KB11-A uses the M8108 System Status Registers (SSR) in slot 13 whereas the KB11-C uses the M8108-YA -- there is no sharing with either the KB11-B or KB11-C

So in the end there are *no* modules that are shared between the 11/45-50 (KB11-A) and either variant of the 11/70.

There is *one* module possibly shared between the 11/55 (KB11-D) and the earlier variant (KB11-B) of the 11/70 -- M8132 (IRC).
There are *two* modules shared between the 11/55 (KB11-D) and the later variant (KB11-C) of the 11/70 -- M8132 (IRC; likely REV. B or higher) and M8123 (RAC).

None of this means what you can't swap and hope-for-the-best, but I'd carefully check for signal compatibility at module edge between the potential swap-pair before inserting and powering-up anything :->. The backplanes are different and all slots are wired uniquely, although slots 1-12 are functionally equivalent across all four systems. IMO, it's not the case that module-sharing between the 11/55 (KB11-D) and either variant of the 11/70 implies smooth sailing for backwards compatibility to the 11/45-50 (KB11-A); DEC certainly didn't think so. I'd expect at least timing differences, and tweaking timing across module-sets not designed to work together could be a *very* exciting (and frustrating) proposition!

However, as a last resort it's certainly something that one can experiment with ...
 
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Hi All;

Thank You PBirkel for You Fine synopsis..
I was trying to do it from Memory and so I think I made at least one mistake..

"" - KB11-B uses the M8133 ROM and ADDR Control (RAC) in slot 9 whereas the KB11-C uses the M8123 ""

Yes, what I have is the M8123 and Not the M8133..

"" - KB11-B uses the M8138 System Status Registers (SSR) in slot 15 whereas the KB11-C uses the M8138-YA ""
And None of the M8138's can be used at all since they are 22 bits wide addressing, and the 11/45 is 18 bits wide addressing..
I have not compared the M8137, with the M8107, but I suspect that they are not the same.. Yes, they are NOT the same for probably the same reason..

On the M8101 GRA and the M8131 at least what I have they are the same..

On the M8102 and on the M8103 if I remember correctly I have one same and one different, but after I get back from my Bible Study this morning, I will get all of what I have out and tell You what I find for sure..
Last night I was working on rewiring some of my Tester for the next stage/modification and so my mind was on that, when I was trying to answer Jack's Question..

Also what is an "" DEC FMPS "" (If it is what I think it may be, I would like to see it and see what all it has to say) ??

THANK YOU Marty
 
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Hi All;

PBirkel, after Bible Study I will take a closer Look at the two Boards, but I think they are the same from my past looking at them..
Then I will report back to You on what I find, with pictures..

THANK YOU Marty
 
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Thanks! I'm *really* curious on this point since DEC otherwise seems to have been disinterested in carrying the same item under what amounts to two stock numbers. That means that inventory would be double and that costs $$ and is inefficient. I really think that a careful inspection will discern differences sufficient to result in a separate module identification. Note that they didn't chose to simply REV the same module# or introduce a -YA variant, both of which they did in other cases. They went for a completely new number ...
 
Hi All;

PBirkel, here is the situation on the M8101 GRA Boards..

I have pictures of both Front and Back, But, I can't get the Camera to focus on the Metal Tabs so the Numbers can't be Read on them..
So I hope You can take my Word on this..
So, The M8101 GRA Board and the M8131 GRA Boards are the same..
On Both Boards on the Back they say, M8101B, BUT on the M8101 the Bar across the Top says M8101 and on the M8131 Bar across the Top it says M8131..

001.jpg 002.jpg

003.jpg 004.jpg

There will be more Comparisons and Pictures in a Bit..

Here are the M8100 and the M8130.. They Both Work in my 11/45..

007.jpg 009.jpg


008.jpg 010.jpg

These Last two corner pictures are of the Modification that is needed..
The 74S64 is what needs to be added to the M8130 11/70 Data Path Board to make it the same, along with all of it's various connections..

THANK YOU Marty
 
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Hi All;

The next two Pictures are of the M8102 and the M8132..
The first picture is the M8102 which is Not Working, and the Second Picture is the M8132 which is my Working Board..

011.jpg 012.jpg


These Last three Pictures are of the M8103 and the two M8123.. The M8103 is the working Board, along with one of the M8123 Boards..

013.jpg 014.jpg 015.jpg

THANK YOU Marty
 
Marty, please don't do photos (just) for me. If we're not going to compare down to the trace-and-component level we've proven nothing. We *expect* the corresponding modules to be _highly_ similar within the family-of-four -- that's the nature of the KB11-A/B/C/D; there was a single CPU design that evolved in particular ways from the 11/45-50 to the 11/70 to the 11/55. If the corresponding modules were renumbered then the onus is on us to prove that there are absolutely no differences, IMO. The fact that differently named maternal ("identical") twins "look alike" doesn't make them interchangeable :->.
 
Hi All;

I got the signals wired to another tie point where I can tie any other signals that I might need to that point, and I am in the process of wiring in 3 each 555 timers, that will serve as clocks and other such needed signals that can be strapped to any of the tie points..
I got one of the 555's all wired up and it works, so I can now finish wiring up the other two of the 555's..
The other two are wired up, but the middle one does not have an Led driver (I ran out of 7404 gates..) and since I figure for at least now, two should be enough.. Hopefully this should be all of the wiring that I need for now..

001.jpg

I think I am close to getting the Memory Management Boards to work, for a short time I got them to Increment on Examine and Deposit will always increment..
At present I don't know what signals from Deposit and Examine affect these boards, But somehow they do, which needs more Investigation..
Which will tell me where to look for Bad or weak IC's on the Memory Management Boards..
I also need to find out How the two Boards are wired together in the 11/45..

THANK YOU Marty
 
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The MMU is basically a series of registers, an adder and a microcode extension to the CPU microcode (sorry if someone reading this was the designer of the 11/45 MMU for reducing your creation to the bare minimum!). I have had a quick look at the schematics - and I can't see why any of the MMU registers should increment on a deposit.

I promised myself to have a look at my SuperPET add-on card I am designing this weekend - but I am ahead of my schedule so I will take another look at the MMU schematics again later. If you have a spare minute or so - can you perform some deposits on your MMU and tell me what address and data values you are depositing and what the observable symptoms are and I will see if I can point you at where to look with your amazing test rig...

I see you mentioned some 555 timers a post or so ago. I was just going to suggest to you that you incorporate some oscillators. You also should consider adding some debounced switches as well with some patching leads to replace some of your on/off switches. Some signals may be clock lines - and will object to being switched on and off with unbounded switches - this may cause undesirable effects when you are testing and "lead you up the garden path" as a result.

The MMU should consist of a bank of registers (8 off supervisor, user and kernel with two registers per mapping. These should be directly addressable via the front panel EXAMINE and DEPOSIT mechanism). If you want - I can suggest a few tests for you?

Dave
 
Hi All;

Dave, I had really been hoping that I would hear from You soon.. You have a way at getting down to the Meat of the problem..
"" If you want - I can suggest a few tests for you? "" YES, PLease..

"" I have had a quick look at the schematics - and I can't see why any of the MMU registers should increment on a deposit. ""

It is not that the Registers are Incrementing, I have Not tried to access any of the Registers at all..

I am trying to access the Lower 24K of memory, just as though I didn't have a Memory Management set of Boards plugged in to the machine..

I turn on the Machine, with the MMU it requires the DC low and AC low to be pulsed.. Whereas with out the MMU it most of the time does not require this..
I set all the switches to '0' and do a Load address, I then do an Examine.. And it show in the Data Led's all Ones..
I just noticed something.. I have turned it off and am letting it set..
When I first turn on the machine, it shows address of '177776.. and Data is '000000.. I press 'Load Address' and all the led's go out (off)..
I depress 'Examine' , address remains at '000000 and Data is '177777..
De-pressing 'Examine does not increment the Address Led's..
But, Depressing the 'Deposit switch' will increment the Address Led's..
Now if I depress AC and DC low and then press the 'Load address switch' it show Data of '000000,
I can then press 'Examine twice and the Address led Increments to '000002, as it should, repressing 'Examine clears the Address Leds and the Data Leds. and it will NOT Increment the address Led's any more..
But, If I was to switch back to the SBJ Board, the Address Led's would Increment with each pressing of the Examine Switch..

I hope that this is clearer than it was previously..

"" You also should consider adding some debounced switches as well with some patching leads to replace some of your on/off switches. Some signals may be clock lines - and will object to being switched on and off with unbounded switches - this may cause undesirable effects when you are testing and "lead you up the garden path" as a result. ""

It's mainly that I am running out of room on the Board, for much more additions, I know of a change that I would like to make, but there isn't room on the Board to do so and that is to change the ground switches to have drives on them so the Ground signal is not a 'Hard' Ground..
And I knew that there would be things that I would discover that I would need to change, it's a work in progress..

THANK YOU Marty
 
Hi All;

I have switched back to the SJB Board, and I am NOT getting the software prompt.. (I can't think of what it is officially called..)
So I need to find out what is not working without the MMU Boards in..
About a month ago It worked, I know I thought I had trouble with what I thought was the GRA Board, but it could be somewhere else..
It does Increment in Memory and it does show the correct contents when 'Examining' the Addresses for the M9312 Board.. And I have tried the M9301 as well..
I have noticed that I am having to Press the AC and DC Low switch where I didn't have to do so before, also, before I had a Bad line in the Cable to the PDR Board and I am wondering if it is acting up or the Board itself is acting up..
Taking the Boards out and looking at the PDR Board revealed that I had piggy-backed one of the 74H01's with a 74S38 and it had slipped a little, but taking that off and plugging everything back in made No difference..
I could replace the 74H01 with the 74S38, as the Pin-out is the same.. And the '38 will drive more TTL Loads..
I have replaced the 74H01 with the 74S38, in a socket..

THANK YOU Marty
 
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Hi All;

Another interesting set of scenarios..

I put into memory with the SJB Board the chase program and I had it running, With this I found one GRA Board that worked and one that did not work.. Both of the Data Paths Boards work..
But, it still will not work with Software prompt..
When I changed to the Memory Management Boards, I could Deposit and Examine the memory Locations for the chase program, but it would Not Run..

THANK YOU Marty
 
With the memory management cards IN - can you use the front panel to DEPOSIT and EXAMINE values in the I&D space Supervisor, User and Kernel PAR registers? These should be 12-bit registers. If you can't do that properly - then you don't stand a chance of the MMU working.

For example, User I space PAR registers 0 through 7 live at 777640 through 777656. The lowest 12 bits (of the 16 bit data) are supported. You should be able to directly DEPOSIT and EXAMINE from these locations in the I/O page.

Dave
 
Hi All;

Dave, Thank You for the Suggestion.. I will try it out..
What should be my Switch settings when I do this and do I use regular Deposit and Examine switches ??

I Examined some of the User spaces, and then I Deposited all '000000 to all of the Kernel, User and Supervisor Locations..
I went and did other things and ran other programs and then I came back and Examined some of them and they had not changed..
I know that this is not an exhaustive test, But I think I can Examine and Deposit to these Registers..

Also, with the Memory Management Boards in and doing the two simple tests from Henk's site I can receive and send a single character, which would seem like it is, at least in the I/O section decoding correctly, maybe.. Using '777560 thru '777566..

Also, on another side Note ---

On my DD-11 ?? (I can't read the last two Letters) on the Middle two Rows what Pins do I connect --5 Volts and +20 Volts for Core, I have a power Supply that Is New Old Stock that has these voltages, and two Core Boards that I can try to see if they will Work in these slots.. They take up two slots, so I will only be able to use one of them..
I can track down where the pins are connected to (on the side of the backplane) once I know what pins go to these voltages..
And If I can get my core to work, I can load things into core using the SJB board and then turn off the power and switch to the MMU Boards, at least that is my thinking..

THANK YOU Marty
 
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