Image Map Image Map
Page 1 of 3 123 LastLast
Results 1 to 10 of 29

Thread: Adding a Programmer's Console to a PDP-8/a

  1. #1
    Join Date
    Jul 2014
    Location
    Rhode Island
    Posts
    1,316

    Default Adding a Programmer's Console to a PDP-8/a

    I have two misbehaving KC8-A PDP-8/a Programmers Consoles that I am trying to get working. The first problem that I need to fix is missing mounting hardware. There are supposed to be two Cabinet Brackets, P/N 7419709-0 and 7419709-1, mounted to the front of the chassis. Screws in the console go into the these brackets to hold the console in place. Part of the drawing from the Engineering Drawings showing the brackets is attached.

    Any idea where I could get two sets of these brackets?

    Programmer's Console Cabinet Bracket 7419709-0.jpg
    Member of the Rhode Island Computer Museum
    http://www.ricomputermuseum.org

  2. #2

    Default

    Don't remember that I have seen those anywhere in mine. But they might be missing. Can't really understand how and where they fit. Do you have the full picture?

    My understanding is that the programmers console is snapped on to those always breaking off knobs. Whatever the name is.

  3. #3
    Join Date
    Jul 2014
    Location
    Rhode Island
    Posts
    1,316

    Default

    My programmer's consoles have screws that go upwards and towards the back from the bottom of the panel and should screw into the metal brackets.
    Programmer's Console Mounting.jpg
    Member of the Rhode Island Computer Museum
    http://www.ricomputermuseum.org

  4. #4

    Default

    Quote Originally Posted by m_thompson View Post
    My programmer's consoles have screws that go upwards and towards the back from the bottom of the panel and should screw into the metal brackets.
    That sounds like a good mod to the original design which as Mattis says were only supported on 4 ‘knobs’. (Mine is like that). When I used them at work back in the 70’s we often needed to remove the panel to access the various interfaces to our test gear and the nylon knobs were always getting snapped off. Much worse now they’ve got so brittle with age!

  5. #5
    Join Date
    Jul 2014
    Location
    Rhode Island
    Posts
    1,316

    Default

    The KC8-A-0 drawings that are revision J and dated 23 January 1975 show the mounting screws.
    Member of the Rhode Island Computer Museum
    http://www.ricomputermuseum.org

  6. #6
    Join Date
    Mar 2004
    Location
    Wilmette, IL (north of Chicago)
    Posts
    732
    Blog Entries
    1

    Default

    Here are some photos - but I no longer have any brackets (or 8/A's):

    Clip-Scan1.jpg

    Clip-Scan2.jpg

    Img_1397.jpg

  7. #7
    Join Date
    Jul 2014
    Location
    Rhode Island
    Posts
    1,316

    Default

    I probably can make some of those.

    Thanks Jack!
    Member of the Rhode Island Computer Museum
    http://www.ricomputermuseum.org

  8. #8

    Default

    Quote Originally Posted by m_thompson View Post
    The KC8-A-0 drawings that are revision J and dated 23 January 1975 show the mounting screws.
    Interesting. I don’t have those drawings. Just had another look and my panel doesn’t have any screw-holes or earthing cables as your drawing shows. I wonder if there were 2 varieties or if it was a mod to address the fixing knob breakages - it IS quite heavy just to hang on the nylon supports and as I said earlier they tend to snap off if you are taking it off and on a lot.

  9. #9
    Join Date
    Jul 2014
    Location
    Rhode Island
    Posts
    1,316

    Default

    Quote Originally Posted by bobaboba View Post
    Interesting. I don’t have those drawings.
    The new front panel drawings are in this set of prints.
    http://www.bitsavers.org/pdf/dec/pdp...hems_Apr81.pdf
    Member of the Rhode Island Computer Museum
    http://www.ricomputermuseum.org

  10. #10
    Join Date
    Jul 2014
    Location
    Rhode Island
    Posts
    1,316

    Default

    Now I need to actually fix the front panel. I can set and read the SR, so lots of the logic is working.
    If I set the MA to 0000 it actually sets to 1400.
    If I set the memory contents to 0000 it sets to 1400.

    So it looks like there are some stuck bits in the bus interface logic on the front panel.
    I already swapped the Option-I board and the behavior was the same.
    Time to look at the 8235 chips.
    Member of the Rhode Island Computer Museum
    http://www.ricomputermuseum.org

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •