• Please review our updated Terms and Rules here

Using PDPGUI to run BASIC

billdeg

billdeg

Technician
Joined
Nov 18, 2003
Messages
3,885
Location
Landenberg, PA USA
Attempting to follow directions here:
http://retrocmp.com/how-tos/using-pdp-11-diagnostics/227-pdp-11-diagnostics-running-them
...to load BASIC into PDP 11/40 with 16K RAM. I can boot up to an @ prompt using CONSOLE ROM of M9312. System seems stable.

Here is the process I am following, what am I doing wrong?

1) got a copy of DEC-11-AJPB-PB.ptap

2) opened MEMORY LOADER. I *think* and here is where I must be wrong... load
start address 000
end address 17464
entry address 016104

3) LOAD, DEPOSIT ALL, VERIFY ALL - all works. I can see the tape values depositing into their respective RAM address. I can verify 100% addresses match what should be in RAM, from the address I used as the start address in 2) above.

4) Still within the PDPGUI program I opened EXECUTION CONTROL window
start program counter 000
hit RESET and START

5) It's supposed (I think) to go into BASIC...but nothing happens, I have to reset the system from the front panel.

I have tried various combinations of start program counter and other addresses, nothing works.

Note I can load BASIC from a regular teletype, but I am not getting why PDPGUI will not load a tape. Maybe I don't understand, am I supposed to load the absolute loader and then the absolute loader actually loads the tape? Am I mistakenly assuming that this step is not needed. Obviously when I load a program from papertape I have to load the bootstrap loader, then the absolute loader, then the absolute tape.

Sorry to be dense....
 
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
 
Apples and oranges. Can you confirm I have the correct addresses loaded? I believe you that you should "just run the tape" but then how do you declare the size of the system? That's part of the process when I use a real tape. That's why I was wondering it there is more to it. Just looking for confirmation for sure that I don't run the abs loader first to then load the tape. I think I am doing something wrong, looking for someone who has actually loaded BASIC using PDPGUI. Could be any PDP 11.
 
Last edited:
The basic manual is here: http://bitsavers.trailing-edge.com/...B-D_PDP-11_BASIC_Programming_Manual_Dec70.pdf
Lots of info. According to the manual basic autosizes memory, so unless you want to force it to use less memory than is available there is nothing to config.

If you use the memory resident absolute loader then it normally goes at the top of memory, so then you need to know the amount of memory available. But if not using the absolute loader (ie, letting PDP11GUI load the software tape) then there is no need to know the memory size beforehand.
 
billdeg said:
2) opened MEMORY LOADER. I *think* and here is where I must be wrong... load
start address 000
end address 17464
entry address 016104
Click to expand...

You did select the "Standard Absolute Paper Tape Image" file format, right?

I have been successful loading BASIC with PDP11GUI on my 11/04. As far as I remember I started it at 16104. Also this was before Jörg included Absolute format in PDP11GUI so I did my own loader which converted to a binary format that was then loaded by PDP11GUI.

Since then I used PDP11GUI to load various diagnostics in Absolute format without any problems.

Have you tried some CPU diagnostics instead?

It should be possible to connect PDP11GUI to SimH to verify that everything is done correctly with a known working CPU.
 
That answers the questionI "should I use the default values", but I ask also if anyone here has used pdpgui to load the tape made avail on the pdpgui sit on an actual 11 20/05/40/45 era machine since the pdpgui enhancement to allow for direct load of the tape. SIMH is obv. not the same thing.

I have an 11/05 that I set up the old way, with an actual tape. When I restart basic on this machine which already has been initialized with papertape basic I simply load address 000 and START. I am greeted with READY and I can go from there.

I wanted to know if loading this ptape image using pdpgui puts me in that same spot as If I was "resuming my session"
 
Last edited:
pdp11.ini file - Is it possible that the default INI file made for an 11/44 does not work with a pdp 11/40 out of the box? For example I have no memory management card installed, and only 16K core. There are things I can do to check this, addresses and vectors, etc.

I think I will hook up a teletype and load programs that way, at least to prove to myself my machine is working "the old way" ... at least with this method I can find out for sure.

Bill
 
I need to rerun the setup program. 11/44 is the default. Not sure the history of this PC's installation of PDPGUI. It does work as is enough to load BASIC into memory or other tape, but I may need to leave the program in core, remove the M9312 and replace with a terminator and THEN run the program. Not sure.
 
billdeg said:
I need to rerun the setup program. 11/44 is the default. Not sure the history of this PC's installation of PDPGUI. It does work as is enough to load BASIC into memory or other tape, but I may need to leave the program in core, remove the M9312 and replace with a terminator and THEN run the program. Not sure.
Click to expand...

PDP11GUI has a Connection menu and a drop down to select the PDP11 target. You should select a M9312 target because that is what kind of language the console emulation speaks. 11/44 console is much more elaborate than than the one in the M9312. The ODT used by 11/03, 11/23 and 11/73 is completely different.
XPsRXQc.png
 
I have had this setting bit thanks for checking.

I can download basic (my test tape) into memory. I have verified the values. I compared with a system where basic was loaded via papertape that works (11/05). Same values in RAM. BUT the pdpgui loaded system (11/40 )halts immediately when I attempt to run from 000 and I have to reset the console. It does not matter if I power down and remove the m9312 after downloading the tape into core, replace the m9312 with a dumb terminator and attempt to start basic outside of pdpgui using the front panel from 000. Same result.

Note my system passes all memory tests within pdpgui.

If this was an s100 systrm I would think I have a port conflict issue.

I can toggle in programs such as echo chars, memory test, so I know I at least have some solid cpu function.

I am wondering with pdpgui and the 11/40 if I need to update registers too after loading a tape. ??

I don't really want to rewire a serial card for TTY but I could, to attemptbto boot / load tapes the orig way.

My gut feeling is that the problem is not hardware, buT I can only prove this if I can successfully load a tape via TTY. If the problem is with the cpu, given I can't load diagnostic tapes, any suggestions where to start probing, which card could be at fault for such an odd case like this?
 
Hi All;

Bill, "" I don't really want to rewire a serial card for TTY but I could, to attempt to boot / load tapes the orig way. ""

You wouldn't have to wire Your Serial Port for TTY as long as it is RS-232, You could Download Your Programs from another Terminal Emulator such as TeraTerm, just for checking things out..
This is How I Load things into my PDP 11/45, I didn't like PDPGUI for many of the same Reasons that You are having trouble with on Your System, I couldn't figure out How to make it work with my /45 as I would have liked..
I can tell it's a good program, but, someone like me who doesn't know nor understand what it needs to make it work with my System, I just went with TeraTerm which I know how to make work..
Since You have Core, You can save things in Memory, that I could Not do, with only RAM, so You could Load in Test programs Via TeraTerm and further Test Your 11/40..

THANK YOU Marty
 
You have successfully loaded basic using teraterm? Do you toggle in bootstrap, then load abs loader, then load the program? Yes I could do that good idea.

PDPGUI starts you directly with the program tape allowing a person to bypass the bootstrap and abs loaders. The root of my question is ... does pdpgui correctly "prep" the system for direct run of an abs tape on 11/40s? Anyone accomplish this?

Thanks everyone.
 
Hi All;

Bill, "" You have successfully loaded basic using teraterm? Do you toggle in bootstrap, then load abs loader, then load the program? Yes I could do that good idea. ""
I have Not actually Loaded in Basic, BUT, I have Loaded in All of the 11/45 Test programs that are available to me..
I had not though of Loading in Basic, nor do I know if it available for the PDP 11/45..
But, Yes, I toggled in the Bootstrap and then the abs Loader and them my Program to be Loaded.. Actually the Bootstrap was in PROM in my M9312 or M9302 (?) BootStrap Card(s), so I didn't have to actually toggle it in..

THANK YOU Marty
 
Marty,

You have the 760A9 ASR33 (TT), PC05 (PP) ROM? I never tried that but I do have one. It works with the DL11? I have to check the manual to see how that works and search the web for comments about this combination. Any tips?

You're saying then that you failed to load the same tapes using PDPGUI that you could successfully load instead using the M9312 and TT ROM?

[EDIT] From the console you type in TT or PR? What works better for a serial card DL11? Does the DL11 have to be 110b?

Can you try to load BASIC just for fun? It should work on a 11/45

here is a copy
vintagecomputer.net/digital/papertape/

b
 
Last edited:
I think it would be a good idea to run some basic CPU test just to verify its operation. Or did you try that already and it was unsuccessful? The GKAAA0 should probably run fine on the 11/40. It is a very basic CPU test. It runs in SimH, of course it is no guarantee that it will run on all hardware however I have tested GKAAA0 on several other PDP11 systems successfully. It should be possible to load it using PDP11GUI and then start it at address 200. I extracted the GKAAA0.BIC binary from a XXDP image (it is in Absolute format) and loaded it using PDP11GUI.

The M9312 has a very limited CPU test which is executed prior to launching the console emulator. But there could be things inside the CPU that still doesn't work.

Do you know for sure that the DL11-W interrupts work? I am not sure whether BASIC make use of interrupts. But if you try run the GKABC0 diagnostics it will fail if the console DL11 has problems with interrupts. Or you can try a very short program to do interrupt based console echo.

Code: 
 001000 mov   #001000,sp  
 001004 mov   #000340,@#177776  
 001012 mov   #000100,@#177560  
 001020 clr   @#177776  
 001024 nop  
 001026 br   001024  
 002000 movb  @#177562,@#177566  
 002006 rti


Code: 
 000060/ 002000  
 000062/ 000340  
 000064/ 000000  
 000066/ 000000  
 001000/ 012706  
 001002/ 001000  
 001004/ 012737  
 001006/ 000340  
 001010/ 177776  
 001012/ 012737  
 001014/ 000100  
 001016/ 177560  
 001020/ 000240  
 001022/ 000776  
 002000/ 113737  
 002002/ 177562  
 002004/ 177566  
 002006/ 000002

What about single stepping from the operator console?
 
Hi All;

Bill, "" You have the 760A9 ASR33 (TT), PC05 (PP) ROM? I never tried that but I do have one. It works with the DL11? I have to check the manual to see how that works and search the web for comments about this combination. Any tips? ""

I'LL have to look tomorrow and see what version of Rom, I have, but that Sounds correct..

"" You're saying then that you failed to load the same tapes using PDPGUI that you could successfully load instead using the M9312 and TT ROM? ""
Most likely it is Operator ERROR and Lack of Understanding of what does what and How to Implement what I want.. It's just not Explained enough for a Software Novice like me..

"" [EDIT] From the console you type in TT or PR? ""
I USE TT, I don't have the Interface to do PR..

"" What works better for a serial card DL11? Does the DL11 have to be 110b? ""
Like I said above I only have Used TT.. And I have it set for 9600b, not 110b..

"" Can you try to load BASIC just for fun? It should work on a 11/45 ""

Yes, Once I clear out my Altair 8800 and my other PC, and find a place for it, and can Clear out the way to get to the 11/45 stuff, it is Buried at Present in my Bedroom on the top Shelf where it is protected, behind a Desk Loaded very High of alot of things, that would need to find another Home, while getting to the 11/45 stuff..
Other than that, Yeah, I can drag out the 11/45, and try it..

THANK YOU Marty
 
thank you for answering my questions.

I will try to use the PC05 ROM, TT command, 9600b outside of the PDPGUI to see if it works.

I will also try to find the GKAAA0 tape and run from PDPGUI
 
Bookmark this
http://retrocmp.com/tools/pdp-11-diagnostic-database/202-pdp-11-diagnostics-database

but seriously, these diagnostics are so obtuse, so hard to determine if the process used to run them is even correct to know if you've found anything actually wrong for sure. So much easier to load and run a program like BASIC from tape to get a clear specific "this is working" answer. I can't believe DEC used this method but I guess it kept the techs employed.
 
Last edited:
Hi All;

Bill, You sound like a man after my own Heart.. "" these diagnostics are so obtuse, ""
What I did was to look in Bitsavers Software side, under PDP 11 and then for the /45.. So, I would look for what there is for the /40 download them, and try to see what will Run and what will not Run.. Using something like I suggested before like TeraTerm and TT mode..
If something fails then look at Bitsavers PDF side for the Listing of that Program to find what is the cause of that problem..
That is what I did..

THANK YOU Marty
 
You must log in or register to reply here.
Back
Top