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Using PDPGUI to run BASIC

It's pretty much down to detective work (i.e. being a Sherlock Holmes). So Bill needs to wear a deerstalker hat for a while!

When I get around to the cards in my 11/45 (I am totally resisting the temptation to remove them at the moment until I have refurbished my power supplies) the first thing I will do will be to thoroughly document all the links and modifications I find on each card as I remove it. I will then pack them away (in an antistatic bag in a protective cardboard box) whilst I continue to checkout the backplane and powering up the backplane itself from the refurbished power supplies.

Offline, I will be comparing the link settings on all of the cards with the 11/45 documentation and print set to identify what the cards are telling me the configuration SHOULD be. I will 100% resist the temptation to change anything though until I know what the configuration of my machine will be. For example, I have already determined that the MOS memory cards that came with the machine (which were not plugged in) do not belong to it! What should have been plugged in were core store boards. I have the driver boards but no physical core store itself. I have also determined that I can't use the MOS memory cards with the backplanes that are in the 11/45 because they are not compatible. I therefore need to 'hunt down' some compatible core store boards - or change the backplane to suite the MOS memory cards I have - or build my own memory board to work in an existing SPC slot (I have a quad UNIBUS development board). If I go down the route of using the core store or MOS memory - I will have to find some more regulators for the lower H742 power supply unit because they are missing. This is what I am able to deduce at the moment. I may find some further inconsistencies when I start looking at the link settings associated with the CPU/FPU/MMU cards? I just don't know until I look.

For Bill's 11/40 example, looking at page 7-4 of http://www.mirrorservice.org/sites/.../DEC-11-HKDAA-A-D_KD11-A_Processor_Manual.pdf identifies that three links changes are required for the installation of the KJ11-A option. You can get a view of all the links by checking the print set for the cards themselves (e.g. for the M7231 see drawing sheet K1-7 of http://bitsavers.trailing-edge.com/pdf/dec/pdp11/1140/KD11-A_RevN_Engineering_Drawings_Nov77.pdf). You should be able to compare the print sets with the actual configuration of the cards themselves to determine the options that should be fitted and then check that the options are present. In Bill's case - he had a spare card that he could use. The alternative would be to re-link the three identified cards for use without the option. The system would have worked once again - but using a default fixed stack lower limit (i.e. the basic operation without the programmable stack limit option).

This (I have found) is usually the best way to work from an unknown position - document thoroughly the state of the machine when you get it and then work out (from the available documentation) what the state of the machine should be from what you have deduced. If there is a mismatch - identify the best way of fixing the problem and proceed from there. If the problem is functional - the machine will just not work fully as intended (as in Bill's case) until the inconsistency is found and rectified. In an extreme case - someone could have inserted some of the cards into the wrong slots - so powering the machine up in the wrong configuration could cause irreparable damage.This latter issue needs to be prevented at all costs if possible.

Just a few of my thoughts - but full marks to Bill for taking the initiative to checkout the link settings; and Al for creating the bitsavers.org website that we all make extensive use of and without which many of the vintage computers that we find would never work again due to the unavailability of documentation...

Dave
 
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daver2 said:
What should have been plugged in were core store boards. I have the driver boards but no physical core store itself. I have also determined that I can't use the MOS memory cards with the backplanes that are in the 11/45 because they are not compatible. I therefore need to 'hunt down' some compatible core store boards - or change the backplane to suite the MOS memory cards I have - or build my own memory board to work in an existing SPC slot (I have a quad UNIBUS development board).
Click to expand...

I think that Marty may have some useful observations on this particular challenge!

daver2 said:
For Bill's 11/40 example, looking at page 7-4 of http://www.mirrorservice.org/sites/.../DEC-11-HKDAA-A-D_KD11-A_Processor_Manual.pdf identifies that three links changes are required for the installation of the KJ11-A option. You can get a view of all the links by checking the print set for the cards themselves (e.g. for the M7231 see drawing sheet K1-7 of http://bitsavers.trailing-edge.com/pdf/dec/pdp11/1140/KD11-A_RevN_Engineering_Drawings_Nov77.pdf). You should be able to compare the print sets with the actual configuration of the cards themselves to determine the options that should be fitted and then check that the options are present. In Bill's case - he had a spare card that he could use. The alternative would be to re-link the three identified cards for use without the option. The system would have worked once again - but using a default fixed stack lower limit (i.e. the basic operation without the programmable stack limit option).
Click to expand...

Thanks for the specificity, Dave :-}.
 
Hi All;

Bill, Congratulations, I hope You had A good night's sleep, once You Found the problem and fixed it..
Yesterday, was a Hard Day's Night for many of us..
Dave, Thank for Explaining things so well..
Dave, I am still not so sure that You can't use some of Your MOS Memory or Core Boards, BUT, I will wait until You have a full List of all of Your MotherBoards and a full List of all of Your Boards and Maybe some Pictures as well, before I say any more.. Your there and I am not there..
"" I will 100% resist the temptation to change anything though until I know what the configuration of my machine will be. ""
I need that kind of Resistance.. Thanks Dave..

"" Marty - are you having problems running my test code as well? ""

I don't know for sure, If I am or if it's because the switches function differently..
later, after I get back from my Thursday morning Bible Study, (somewhere about 9:00 to 10:00 my time) I will give You more Details, and try to Run Your Programs and give You some Results..
But, here is an Example, Putting Zero's at '200 to '210..
I have Address Load at '200, Halt switch is Down (halted), I press Start.. I have bit 7 led on and nothing else.. All the Address light light up for a second, then all go out, except for bit 7 ('200), and all of the DATA lights are on..
I Re-press the Address Load switch bit seven stays on, and all of the Data lights go out.. Halt switch is Down, I press Continue..
Address light bit 7 and bit 1 come on a '202.. and all of the Data lights come on.. I press Continue again and I get a '204..

I have copied over to my site what was here..

I have copied the above over on to my site, so as not to Steal Bill's Thunder..

Congratulations, again , Bill..

THANK YOU Marty
 
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Congrats, you Da man. Good to see you got it up and running. Next step is getting the drives up and maybe that huge nine track transport you have. A working 11/45 with an open reel transport will qualify you as one of the “Big Kahunas” in the DEC world!
Maybe we can get together after the holiday and play around with the RL drives? Do you have all the bits?
 
thanks. It's an 11/40 not a 11/45. I think I have everything I need but I am not 100% satisfied the CPU is working correctly OR I have three bad drive M7762 controllers. I was wondering if I could mail you some of the portable parts so you could test them at your place without having to actually drive up (or me drive down). I'd love to get together to test and get the RL drive(s) working when schedule permits. I work at the InfoAge museum this Sunday.

b
 
SO...To close this out I am able to load and run BASIC now. It seems to work just fine. BASIC is not as good at RT11 but it is a way to interact with the computer and have a little fun.

I really wish to thank everyone who helped me out. Seriously, thanks.

P.S. PDPGUI is a fantastic tool. Brilliant.
 
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AK6DN said:
Load and go of that papertape image seems to work on SIMH, so either the tape is not loading correctly on your system, or your system is not as stable as it needs to be. Can you run CPU and memory diagnostics and have them pass?

My understanding is that PDP11GUI will load absolute format paper tapes directly, so you should not need to deal with the absolute loader.

Code: 
[503] pdp11
PDP-11 simulator V4.0-0 Beta        git commit id: d8aafde7
sim> load basic.pt
sim> ex -lm 0
0:      JMP 3044
sim> ex -lm 3044-3077
3044:   MOV 13662,R5
3050:   INC R5
3052:   CLR 13666
3056:   MOV 13712,SP
3062:   CLR 13674
3066:   CLR 13702
3072:   CLR 13660
3076:   MOV #1,13700
sim> go 0

READY
Click to expand...

FYI - Just for the record, when I reproduce the above and go 16104 (or 0), the my system freezes, I can't do anything. I am working on why.

UPDATE: I was not running from PDPGUI, I was using SIMH 3.9 directly on my raspberry pi. I got it to work by loading the bootstrap and abs loaders first.

Bill
 
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