Image Map Image Map
Page 2 of 2 FirstFirst 12
Results 11 to 17 of 17

Thread: UniBone: Linux-to-DEC-UNIBUS-bridge, year #1

  1. #11
    Join Date
    Jun 2012
    Location
    UK - Worcester
    Posts
    3,185

    Default

    Just checked my 11/45 backplane and (you are 100% correct) the SPC slots only have the BG/BR wired and not the NPR/NPG.

    Thanks for the 'heads-up' Joerg.

    A little bit of wire wrapping therefore required...

    Dave

  2. Default

    Quote Originally Posted by daver2 View Post
    Just checked my 11/45 backplane and (you are 100% correct) the SPC slots only have the BG/BR wired and not the NPR/NPG.

    Thanks for the 'heads-up' Joerg.

    A little bit of wire wrapping therefore required...

    Dave
    Volker in Berlin goes a "wrap-less" route: he breaks NPG from the end terminator back to UniBones NPGIN and from NPGOUT forward to the terminator again.
    He uses an "UniProbe", but this will work with M930 also.
    http://www.retrocmp.com/tools/uniprobe

    Joerg

  3. #13
    Join Date
    Dec 2011
    Location
    Oakland, CA
    Posts
    135

    Default

    Quote Originally Posted by daver2 View Post
    Just checked my 11/45 backplane and (you are 100% correct) the SPC slots only have the BG/BR wired and not the NPR/NPG.
    Out of curiosity, Dave -- what's the serial number on your 11/45 backplane/system?

    Noel and I found while working through a Unix V6 boot issue on my machine last year that there are discrepancies with very early '45s and their memory parity handling as well. This turned out to be unrelated to my boot issue, but was uncovered during investigations along the way... It does impact the ability to run certain memory diagnostics.

    So far I have not found a set of schematics that 100% accurately reflect the revisions of various CPU boards that are in my machine, nor have I managed to find the detailed ECO contents necessary to get there by "subtraction". Things are close enough that I was still able to debug and repair my machine, though. Probably a good topic for a different thread when you get further in to your restoration!

    --FritzM.

  4. #14
    Join Date
    Jun 2012
    Location
    UK - Worcester
    Posts
    3,185

    Default

    I'll have a look. It will have to be next weekend now (I will be on a business trip shortly)...

    Fortunately, I have the complete documentation pack that came from DEC for my machine .

    Dave

  5. #15

    Default

    I am interested in a UniBone, I've been putting off sending in an order for a while. I'll get one in so my interest can be counted. I hope to make a hardware PDP with emulated drives available for student tinkering (since the drives are what is most likely to dislike running for days or weeks at a time after 30+ years).

  6. #16

    Default

    Quote Originally Posted by daver2 View Post
    Just checked my 11/45 backplane and (you are 100% correct) the SPC slots only have the BG/BR wired and not the NPR/NPG.

    Thanks for the 'heads-up' Joerg.

    A little bit of wire wrapping therefore required...

    Dave
    So that would mean that the NPG is wired directly from the Unibus in to the Unibus out slot then? I've never seen a backplane like that. And I thought I had seen most everything.

  7. #17

    Default

    Quote Originally Posted by Joerg Hoppe View Post
    Volker in Berlin goes a "wrap-less" route: he breaks NPG from the end terminator back to UniBones NPGIN and from NPGOUT forward to the terminator again.
    He uses an "UniProbe", but this will work with M930 also.
    http://www.retrocmp.com/tools/uniprobe

    Joerg

    Yes

    IMG_6723_mark.jpg

    It's like shown in the picture. If the Unibone is not connrcted with a cable I use a simple jumper. Maybe you have to cut a trace if you use a M930.

    Best regards
    Volker

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
  •