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Build your own PDP 8I, Part 2..

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

    THANK YOU Marty

    Leave a comment:


  • pbirkel@gmail.com
    replied
    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 :->!

    Leave a comment:


  • Marty
    replied
    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.

    Leave a comment:


  • Marty
    replied
    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.

    Leave a comment:


  • jackrubin
    replied
    Mmm - and maybe deal with ION/IOFF?? :>)
    After all, it's summer and you must have lots of free time.

    Leave a comment:


  • m_thompson
    replied
    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?

    Leave a comment:


  • m_thompson
    replied
    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!

    Leave a comment:


  • antiquekid3
    replied
    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

    Leave a comment:


  • Marty
    replied
    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

    Leave a comment:


  • Marty
    started a topic Build your own PDP 8I, Part 2..

    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
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