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Build your own PDP 8I, Part 2..

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    #16
    Hi All;

    It doesn't work right with the Mod, but it looks very promising, I have an errand to do and so I won't be back till sometime between 10:00 and 11:00.. Then I can single step thru the various steps and see what/where the problem lies..

    THANK YOU Marty

    Comment


      #17
      Hi All;

      I'm back.. I have tried a few variations, and I need to put them down on paper and make a list of what does what..
      PBirkel, I haven't forgotten about Your request..

      THANK YOU Marty

      Comment


        #18
        Hi All;

        I found a variation of something that seems to work with this program..

        Address 0000 Data 0000
        Address 0001 Data 7200
        Address 0002 Data 3000
        Address 0003 Data 2005
        Address 0004 Data 7402
        Address 0005 Data 5001

        It Starts at Address 0001.. I will run continuously and Not Halt.. I think this is correct..
        Next is Kyle's Program.. I will let You Know..

        I does Not run Kyle's program, but it is not what one would think as to why..

        Address 0000 Data 0000
        Address 0020 Data 7320
        Address 0021 Data 7010
        Address 0022 Data 2000
        Address 0023 Data 5022
        Address 0024 Data 7430
        Address 0025 Data 5027
        Address 0026 Data 5021
        Address 0027 Data 7004
        Address 0030 Data 2000
        Address 0031 Data 5030
        Address 0032 Data 7430
        Address 0033 Data 5021
        Address 0034 Data 5027
        Address 0035 Data 0000
        Address 0036 Data 0000
        Address 0037 Data 0000

        I start it 0020 and the next instruction, which should show it at 0021, instead is at 0000 !!!!! Go figure..
        I will put it into single step mode and see what shows up..
        I re-assembled Kyle's program to start at 0001 instead of at 0020, but not any better.. I need to take a closer look at things..

        THANK YOU Marty
        Last edited by Marty; June 1, 2015, 12:25 PM.

        Comment


          #19
          Marty, remember that locations 10-17 are autoincrement and will give very weird behavior if you reference them indirectly.

          Comment


            #20
            Hi All;
            Kyle, Thank You for the reminder, Which was Why I wanted to try it starting at 0001.. I was kind of thinking the same thing..
            I will put it on the back Burner for awhile.. Maybe something will come to mind..

            PBirkel, here is the first of the many differences between the two lists, (There will be many edits)..
            Also, it may be Helpful to look at the Pages under Your copied PDF format for easier Viewing..

            On the INT sorted List A10 (M16) (page 11) Shows pin 1 of the 7430 originally going to A45-6 (M10-6) it is crossed out and is wired to B47-3 (L8-3).. It is also wire to A98-10 (K19-10)..
            Thereby eliminating Signal A0 from the equation.. When I first tried this, before finding the 'F' enable not working, the PDP 8i clone would not work with this signal missing.. I have not tried it since then, I will put it on my list to do..
            On the EXT sorted list M16 (A10) (page 112) shows pin 1 of the 7430 going to M10-6 (A45-6) and K19-10 (A98-10)..

            On the INT sorted List A11 (K4) (page 12) Shows pin 2 of the 7402 originally going to A12-9 (M12-9) and also to A43-9 (K2-9) which has been crossed out..
            Also on the same page A11 shows pin 4 going to A11-3 (K4-3) and also to A43-11 (K2-11) which is crossed out and P1-60 is written in..
            This Eliminates two of the Signals from G16, which when another mod is applied, will do the same thing only it will Simplify the circuit.. At this time I have Not applied this Change..
            On the EXT sorted List K4 (page 74) shows pin 2 wired to M12-9 (A12-9) and also K2-9 (A43-9)..

            On the INT sorted List A13 (M15) (page 14) pin 5 goes to A52-5 (K14-5) and has been written in (added) A36-3 (G16-3).. This is part of the above mentioned Mod..
            On the EXT sorted List M15 (A13) (page 111) pin 5 goes to K14-5 (A52-5)..

            On the INT sorted List A19 (E1) (page 20) pin 3 goes to C1-1 (J6-1) and has been written in (added) A21-1 (E15-1)..
            Signal has been changed from F1 to F0.. I have implemented this change and it agrees with the Equations..
            On the EXT sorted List E1 (A19) (page 3) goes to J6-1 (C1-1)..

            On the INT sorted List A21 (E15) (page 22) pin 1, A33-13 (E11-13) is taken off and it is wire to A19-3 (E1-3)..
            Signal has been changed from F1 to F0.. I have implemented this change and it agrees with the Equations..
            On the EXT sorted List E15 (A21) (page 17) is wired to E11-13 (A33-13)..

            More on the next posting..

            THANK YOU Marty
            Last edited by Marty; June 1, 2015, 03:33 PM.

            Comment


              #21
              Hi All;

              More differences between the lists..

              On the INT sorted List A33 (E11) (page 34) pin 13 goes to A8-3 (G9-3) and A21-1 (E15-1) is crossed off..
              On the EXT sorted List E11 (A33) (page 13) pin 13 goes to G9-3 (A8-3) and E15-1 (A21-1)..

              On the INT sorted List A36 (G16) (Page 37) pin 3 goes to A43-10 (K2-10) and is crossed off and A13-5 (M15-5) is written in..
              This is part of the Mod I referred to in the last posting.. A simplification of the circuit.. I have not implemented it..
              On the EXT sorted List G16 (A36) (page 50) goes to K2-10 (A43-10)..

              On the INT sorted List A37 (E4) (page 3 Pin 4 has it going to B19-1 (F12-1) which is crossed out and it is wired to A37-5..
              Signal A0 is eliminated.. I have the pin Floating..
              On the EXT sorted List E4 (A37) (Page 6) is going to F12-1 (B19-1)..

              On the INT sorted List A43 (K2) (page 42) pin 8 goes to A36-4 (G16-4) and it is crossed out..
              On the INT sorted List A43 (K2) (page 42) pin 9 goes to A11-2 (K4-2) and it is crossed out..
              On the INT sorted List A43 (K2) (page 42) pin 10 goes to A36-3 (G16-3) and it is crossed out..
              On the EXT sorted List K2 (A43) (page 72) pin 8 goes to G16-4 (A36-4)..
              On the EXT sorted List K2 (A43) (page 72) pin 9 goes to K4-2 (A11-2)..
              On the EXT sorted List K2 (A43) (page 72) pin 10 goes to G16-3 (A36-3)..
              This finishes the Mod referred to on last posting.. I have not implemented it..

              On the INT sorted List A45 (M10) (Page 44) pin 3 goes to A9-10 (M1-10) and A45-6 (M10-6) has been added..
              On the INT sorted List A45 (M10) (Page 44) pin 6 goes to B47-3 (L8-3) and A10-1 (M16-1) have both been crossed out and A45-3 has been added..
              A0 is eliminated and I have left M10-6 floating..
              On the EXT sorted List M10 (A45) (page 106) pin 3 goes to M1-10 (A9-10)..
              On the EXT sorted List M10 (A45) (page 106) pin 6 goes to L8-3 (B47-3) and M16-1 (A10-1)..

              On the INT sorted List A49 (G4) (page 4 pin 2 goes to B24-12 (F2-12) and B35-4 (H8-4) Both have been crossed out and attached to P2-55 (MB4)..
              On the EXT sorted List G4 (A49) (page 3 pin 2 goes to F2-12 (B24-12) and H8-4 (B35-4) (PC4)..
              On this and the following Signals involving PC00 thru PC04, I have tried it using MB00 thru MB04 and it doesn't WORK !! So, I have Left all of these attached to PC00 thru PC04..

              THANK YOU Marty
              Last edited by Marty; June 1, 2015, 05:07 PM.

              Comment


                #22
                If single-stepping instruction 7430 (CLA CLL CML) causes the PC to be cleared, I'd say there are definitely issues. Do each of those instructions by themselves work? Do two instructions together work? That'd be where I'd begin debugging that.

                Try single-stepping:
                0000/ 7200 CLA
                0001/ 7100 CLL
                0002/ 7020 CML
                0003/ 7300 CLA CLL
                0004/ 7220 CLA CML
                0005/ 7120 CLL CML
                0006/ 7320 CLA CLL CML

                Maybe you can figure out from there what the issue might be.

                Comment


                  #23
                  Hi All;

                  More differences between the lists..

                  On the INT sorted List A50 (G3) (page 49) pin 2 goes to B24-2 (F2-2) and B31-4 (H12-4) Both have been crossed out and attached to P1-78 (MB0)..
                  On the EXT sorted List G3 (A50) (page 37) pin 2 goes to F2-2 (B24-2) and H12-4 (B31-4) (PC0)..

                  On the INT sorted List A50 (G3) (page 49) pin 5 goes to B24-5 (F2-5) and B32-4 (H11-4) Both have been crossed out and attached to P1-84 (MB1)..
                  On the EXT sorted List G3 (A50) (page 37) pin 5 goes to F2-5 (B24-5) and H12-4 (B32-4) (PC1)..

                  On the INT sorted List A50 (G3) (page 49) pin 10 goes to B24-7 (F2-7) and (P1-89) Both have been crossed out and attached to P1-90 (MB2)..
                  On the EXT sorted List G3 (A50) (page 37) pin 10 goes to F2-7 (B24-7) and (P1-89) (PC2)..

                  On the INT sorted List A50 (G3) (page 49) pin 12 goes to B24-10 (F2-10) and B34-4 (H9-4) Both have been crossed out and attached to P1-46 (MB3)..
                  On the EXT sorted List G3 (A50) (page 37) pin 12 goes to F2-10 (B24-10) and H9-4 (B34-4) (PC3)..
                  On this and the following Signals involving PC00 thru PC04, I have tried it using MB00 thru MB04 and it doesn't WORK !! So, I have Left all of these attached to PC00 thru PC04..

                  Thank You Marty
                  Last edited by Marty; June 1, 2015, 06:21 PM.

                  Comment


                    #24
                    Hi All;
                    Thank You Kyle for the information and the small program, I will probably try it tomorrow, when I get the Machine back in front of me..
                    At present, I am trying to get all of the Wire-Listing Differences up-loaded..
                    Note -- That these are Wire List differences and NOT Schematic to wire List Differences..
                    Schematic to wire List Differences is for another List..

                    THANK YOU Marty

                    Comment


                      #25
                      Hi All;

                      More differences between the lists..

                      On the INT sorted List B19 (F12) (Page 80) pin 1 A37-4 (E4-4) is crossed from the List and B18-1 (F13-1) is left attached..
                      On the EXT sorted List F12 (B19) (page 30) has attached to pin 1 E4-4 (A37-4) and F13-1 (B-18-1)..
                      I have E4-4 floating..

                      On INT sorted List B24 (F2) (Page 85) pin 2 has A50-2 (G3-2) and P1-77 attached to it, A50-2 has been crossed off and B31-4 (H12-4) written in its place..
                      On EXT sorted List F2 (B24) (Page 20) pin 2 has G3-2 (A50-2) and P1-77 attached to it.. PC0

                      On INT sorted List B24 (F2) (Page 85) pin 5 has A50-5 (G3-5) and P1-83 attached to it, A50-5 has been crossed off and B32-4 (H11-4) written in its place..
                      On EXT sorted List F2 (B24) (Page 20) pin 5 has G3-2 (A50-5) and P1-83 attached to it.. PC1

                      On INT sorted List B24 (F2) (Page 85) pin 7 has A50-10 (G3-10) and B33-4 attached to it, A50-10 has been crossed off and (P1-89) written in its place..
                      On EXT sorted List F2 (B24) (Page 20) pin 7 has G3-10 (A50-10) and H10-4 attached to it.. PC2

                      On INT sorted List B24 (F2) (Page 85) pin 10 has A50-13 (G3-13) and P1-95 attached to it, A50-13 has been crossed off and B34-4 (H9-4) written in its place..
                      On EXT sorted List F2 (B24) (Page 20) pin 10 has G3-13 (A50-13) and P1-95 attached to it.. PC3

                      On INT sorted List B24 (F2) (Page 85) pin 12 has A49-2 (G4-2) and P2-56 attached to it, A49-2 has been crossed off and B35-4 (H8-4) written in its place..
                      On EXT sorted List F2 (B24) (Page 20) pin 12 has G4-2 (A49-2) and P2-56 attached to it.. PC4

                      On INT sorted List B34 (H9) (Page 92) pin 4 has A50-13 (G3-13) crossed off and B24-10 (F2-10) written in..
                      On the EXT sorted List H9 (B34) (page 59) pin 4 has G3-13 (A50-13) is listed..

                      On INT sorted List B35 (H (Page 93) pin 4 has A49-2 (G4-2) crossed off and B24-12 (F2-12) written in..
                      On the EXT sorted List H8 (B35) (page 5 pin 4 has G4-2 (A49-2) is listed..

                      On INT sorted List B47 (L (Page 105) pin 3 has C2-1 (J5-1) and A45-6 (M10-6) A45-6 is crossed off and A10-1 (M16-1) is written in..
                      On EXT sorted List L8 (B47) (page 93) pin 3 has J5-1 (C2-1) and M10.6 (A45-6) is listed..

                      That is all of the Write in Differences, I have NOT checked the rest of the IC's (Gates) that have nothing written on them..
                      I still need to do that..

                      THANK YOU Marty
                      Last edited by Marty; June 1, 2015, 07:44 PM.

                      Comment


                        #26
                        Originally posted by Marty View Post
                        That is all of the Write in Differences, I have NOT checked the rest of the IC's (Gates) that have nothing written on them.
                        Thank you Marty; a real labor of love! Which list do you think is correct(er), if either? We're clearly "a ways" from PCB-ready :-<.

                        Comment


                          #27
                          Hi All;
                          PBirkel, Thank You for asking.. "" Which list do you think is correct(er) ""
                          It seems like the EXT List is more correct, and Is the one I originally Built from..

                          THANK YOU Marty

                          Comment


                            #28
                            Hi All;
                            Kyle, here is a Simplified circuit for the PC (L) which is the signal for Loading(clocking) the PC Register..
                            I am only concerned with the ISZ part of the circuit, to make the ISZ work, I took G12 out of the circuit..
                            I had also tried switching E5 a 7400 Nand gate with a 7402 Nor gate in a different socket..
                            I had also tried inserting an Inverter 7404 Not gate between E6 pin 6 and G2 pin 1..
                            Part of what I don't understand is 'Why' the MB=0 signal is Nanded with the ISZ Signal, Yes, MB=0 would be low if there is nothing in the MB Register such as when You would have in Your program '2000' and but any other time it would be 'high' and the ISZ signal is inverted so it would be high as well.. Why is the MB=0 signal used there at all ??
                            I can see that They (He) had problems in this area, in the Lab manual it has
                            + (ISZ . MB=0 + JMS) . CP2
                            in another Equation it has
                            + (MB=0 * ISZ + JMS) * CP2
                            and an older one
                            + ISZ * CP2
                            The period (.) I have used for the Dot in the middle of the Equation, since I don't have a dot that will be in the middle, but only the period..

                            002.jpg

                            I will get out the Machine and try Your Program, and let You know about the results..
                            As you probably already know, changing one circuit, can cause a change in something else..
                            So, I will check these again, with the modified ISZ circuit, and see if they still work..

                            THANK YOU Marty
                            Last edited by Marty; June 2, 2015, 07:07 AM.

                            Comment


                              #29
                              Hi All;

                              I have a first problem,
                              Address 0002 Data 7020 CML does not work any more, it goes into the weeds !!
                              So, this is the first thing to check out..
                              My friend Bruce, stopped by and Helped me some, I have put the circuit back to its original wiring, and with a Re-write of my Test Program.. I probably had a mis-understanding of what the ISZ instruction was/is actually doing..
                              So, I am going to try this rewritten program and see if it passes, if it does, then I will retry Kyle's program from posting #22 and see if it works..
                              Then it would be going back to his KITT program and try to see why/where it fails..

                              THANK YOU Marty
                              Last edited by Marty; June 2, 2015, 10:03 AM.

                              Comment


                                #30
                                Hi All;
                                I found a complexity of errors..
                                First I found that my 7404 extender cable and Pin-out board, I had made a mistake when I wired it.. The front wires were correct, pins 1 thru 7.. But, the rear wires pins 8 thru 14 were one pin off.. Also, yesterday when I had made a table of trying various combinations, Of Ic's and settings, I not only had the above mentioned mistake(s), but on one of the signals that I though I was varying, I was using the wrong pins, so I was not varying that signal at all, but some other signal..
                                But, after fixing all of the above it still would not work as shown in the Schematic, I found that I still had to bypass the 7404 G12 pins 1 and 2.. After tying them together on my Bread Board and not shorting out the 7404, the ISZ instruction worked, but the CLL instruction did not work..
                                But, by accident I got it to work.. Before that I had tied the OPG1 pin to OPG1.L instead of the OPG1.H I had retied it to when I returned everything back to the way it was in an earlier posting.. So, it was some better, and I had tried the pin that goes to the Signal F0 in one listing and F1 in the other listing, and after taking it off of the pin I had it wired to, so I could use a Jumper wire and try out each pin separately one run after the other.. I took it off of either connection, and I Ran the program, and it Ran without any problems !!
                                So, for now the wire is attached to nothing.. I have run the ISZ test program and it passes that.. I have run Kyles Cxx tests, (listed on post #22) and Now it Passes those as well.. I tried Kyles Kitt program, and it still fails.. I need to test RAL and RAR and SZL before trying that program again.. I also need to test the rest of the various Skip instructions..
                                So, that is the progress as of today/tonight..

                                THANK YOU Marty

                                Comment

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