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Build your own PDP 8I, Part 2..

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    Build your own PDP 8I, Part 2..

    Hi All;

    I am starting a new thread/posting for this long and winding road to hopefully eventual success..

    http://www.vintage-computer.com/vcfo...wn-PDP-8I-book

    http://www.vintage-computer.com/vcfo...8I-book/page19

    THANK YOU Marty

    #2
    Hi All;

    I have tried to run programs from a Link that (I think) M-Thompson gave me..
    I have run the first of Group 1 instructions, and it fails one instruction -- BSW 7002..
    But it passes the following instructions -- CLA, CLL, CMA, CML, RAR, RAL, RTR, RTL, IAC and HLT..

    THANK YOU Marty

    Comment


      #3
      That's a good thing, Marty! The 8/I didn't support this instruction, only 8/E and later. Probably wouldn't be hard to add it. At the moment, you do need this instruction to get my SerialDisk software working on an 8, but I'm guessing you're still a few months out from having two working serial ports. And congrats on the excellent progress! It's very inspirational. Maybe once you've debugged yours sufficiently, we can generate a known good schematic and do a board layout.

      Kyle

      Comment


        #4
        Originally posted by Marty View Post
        But it passes the following instructions -- CLA, CLL, CMA, CML, RAR, RAL, RTR, RTL, IAC and HLT..
        Very cool!
        Member of the Rhode Island Computer Museum
        http://www.ricomputermuseum.org

        Comment


          #5
          Originally posted by antiquekid3 View Post
          At the moment, you do need this instruction to get my SerialDisk software working on an 8,
          Kyle, could replace the BSW with some non-8/e specific instructions so we could use it with the PDP-12 that we are working on?
          Member of the Rhode Island Computer Museum
          http://www.ricomputermuseum.org

          Comment


            #6
            Mmm - and maybe deal with ION/IOFF?? :>)
            After all, it's summer and you must have lots of free time.
            Jack
            www.computerarium.org

            Comment


              #7
              Hi All;
              Thank You, Jack for Your suggestion.. "" After all, it's summer and you must have lots of free time. ""
              Not as much as You might think, there are alot of Trailer Issues, that have come up since the flood, that just now are showing up.. And need fixing and constant attention..
              I Looks like the ISZ Instructions is working, I am waiting for the test to finish, to also evaluate the SZA instruction as well..
              It partially has ION/IOFF working, but there needs to be some wiring changes in that section, as well as numerous other stuff before I/O would work at all.. There would need to be another Socket added for the I/O signals that would be put on the Memory Board, turning it into a Memory/I-O Board..
              Kyle, Thank You for the very Kind words and information on the BSW instruction..
              "" but I'm guessing you're still a few months out from having two working serial ports. ""
              It shows how to wire up One Port, but NOT two Ports, it does give some hints, but nothing more..
              But, at present, even One Port would be of a Great Help..
              I am looking at the I/O circuit and trying to decide what I need to do and in what way I need to do it..
              I have just downloaded "Introduction to Programming" PDP 8 version.. And will be trying things out with it as a guide..
              I have speeded it up, I changed the 555 timer timing resistors from 100k to 10K and now to 1K, in comparison to before it is now flying..

              Here are a couple of pictures..

              001.jpg 002.jpg

              THANK YOU Marty
              Last edited by Marty; May 29, 2015, 03:08 PM.

              Comment


                #8
                Hi All;

                I looked at Kyle's program and found out I had made a copy Error.. I have Entered the Correct program into the computer, and it did not work.. Upon further inspection, I found that 'now' the CML Instruction does not work, I will need to investigate..
                It may need to have the OPGx Signal changed and or looked at.. While I am at it I will check CLL and CLA..
                I got it to work, but I really didn't do anything.. I took off the wire from the pin and used a wire jumper to check it on both OPG1. Hi and OPG1.LO, and it worked on OPG1.Hi, like it was previously wired or so I thought.. I re-wired it and it now works..
                I changed the program a little and now I need to find out Why SNL 7430 doesn't work.. Hopefully it is something simple..
                It maybe the ISZ instruction, so this will need more looking into on Monday.. I had made a Mod to it and now that I temporally undid the Mod then there are other problems..

                THANK YOU Marty
                Last edited by Marty; May 30, 2015, 06:47 PM.

                Comment


                  #9
                  I have set up a folder with all LD12-related files in my possession at:

                  http://n8vem-sbc.pbworks.com/w/brows...12%20PDP-8%2FI

                  I believe that at the moment you'll need to register in order to access that folder, but that's no worse than registering at VCF.

                  The N8VEM folks are micro-oriented, but wide-ranging. Possibly some folks here already know of them. If not, maybe you'd like to?

                  See overview at: http://n8vem-sbc.pbworks.com/w/page/4200908/FrontPage

                  (Note that there's a lot more going on there than depicted in that one photo! Dig around some ...)

                  And ... congratulations on your steady progress Marty :->!

                  Comment


                    #10
                    Hi All;
                    Thank You, Pbirkel for posting these online for others to have access to, and sharing these files with Everyone..

                    THANK YOU Marty

                    Comment


                      #11
                      Originally posted by Marty View Post
                      Hi All;
                      Thank You, Jack for Your suggestion.. "" After all, it's summer and you must have lots of free time. ""
                      Not as much as You might think, there are alot of Trailer Issues, that have come up since the flood, that just now are showing up.. And need fixing and constant attention..
                      I Looks like the ISZ Instructions is working, I am waiting for the test to finish, to also evaluate the SZA instruction as well..
                      It partially has ION/IOFF working, but there needs to be some wiring changes in that section, as well as numerous other stuff before I/O would work at all.. There would need to be another Socket added for the I/O signals that would be put on the Memory Board, turning it into a Memory/I-O Board..
                      Kyle, Thank You for the very Kind words and information on the BSW instruction..
                      "" but I'm guessing you're still a few months out from having two working serial ports. ""
                      It shows how to wire up One Port, but NOT two Ports, it does give some hints, but nothing more..
                      But, at present, even One Port would be of a Great Help..
                      Marty, I may be mistaken, but I think Jack was referring to my infinite amount of free time now that I'm off from school for the summer. Unfortunately, I've moved up to Baltimore for the summer and am working full time, which doesn't give me too much time for hobbies.

                      Originally posted by jackrubin View Post
                      Mmm - and maybe deal with ION/IOFF?? :>)
                      After all, it's summer and you must have lots of free time.
                      To add ION/IOFF support for SerialDisk? If so, does anyone really need support for that? I am having trouble thinking of a use case. During block transfers, the PDP-8 isn't doing anything but handling transfers, and with the speed of the computer SerialDisk is running on, it should never have any trouble keeping up, even at 230.4k baud, which, besides the Omni-USB board, is the fastest I've ever run SerialDisk at.

                      A few things that are in the works are a parallel version utilizing a DR8-E connected to a microcontroller, as well as getting SerialDisk ported to the DECmate series. Still figuring out the darned serial port there. I'll start a thread of SerialDisk discussion separately, though.

                      Michael, I will try to look into replacing BSW with a few RTR/RTL/RAR/RALs and such. I think I have enough room to do that now, even in the cramped system handler. Another thing in the works is modifying the non-system handler to support four RK05 images, versus the current two. That'll also require a few minor mods to the server, but again, those are quite minor and involve some copy-paste-modify.

                      Kyle

                      Comment


                        #12
                        Originally posted by Marty View Post
                        Hi All;
                        Thank You, Pbirkel for posting these online for others to have access to, and sharing these files with Everyone..

                        THANK YOU Marty
                        Well, don't thank me. They come from someone close to one of the book authors. I've been slow to post them because there has been minimal interest in them from folks here :-<. Anyway ...

                        My objective remains to move the wire-list(s) -- which I've been repeatedly assured *is* correct (one is simply the inverse of the other) -- to a PCB tool and eventually to fabricate a PCB as well as the exactly-corresponding schematic. Your difficulties using those wire-lists are quite worrying. I remain hopeful that when you have a working implementation your notes will be sufficient to identify where there may be errors in the source materials.

                        Note that Oscar V., over on the N8VEM forum, has expressed interest in putting together a front panel-derivative from his PiDP-8 project. That would be quite nice, but there are lots of questions to be answered first ...

                        Keep on wrapping ... (and, alas, unwrapping).

                        Comment


                          #13
                          Hi All;
                          PBirkel, there ARE differences between the two lists, so far they are write in on the IntList versus the ExtList, but I have not had time to check everything between the two..
                          I will on Monday be checking to see if by eliminating one 7404 gate and changing one 7400 gate to a 7402 gate might make ISZ work..

                          THANK YOU Marty

                          Comment


                            #14
                            Originally posted by Marty View Post
                            Hi All;
                            PBirkel, there ARE differences between the two lists, so far they are write in on the IntList versus the ExtList, but I have not had time to check everything between the two..
                            THANK YOU Marty
                            Not asking you to but ... could you provide a specific example(s)? I'd like to verify it/them for myself. These line printer listings are not-so-clear, and thus may be subject to misinterpretation. Would like to see if there's an objective discrepancy, please.

                            Comment


                              #15
                              Hi All;
                              PBirkel, No Problem.. I will List what I have of them Tomorrow, for You to Look at..
                              I think, but I don't know for sure, But, I think one is an Earlier listing and the other is a Later Listing..

                              THANK YOU Marty

                              Comment

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