VAX 11/725 missing a memory board (M8750) - DEC

This is a discussion on VAX 11/725 missing a memory board (M8750) - DEC ; Hi, those who read my previous post might have guessed that i'm trying to resurrect an old VAX 11/725: that's right, but this dinosaur is giving me a lot of problems First i had problems with the dead power supply ...

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Thread: VAX 11/725 missing a memory board (M8750)

  1. VAX 11/725 missing a memory board (M8750)

    Hi,
    those who read my previous post might have guessed that i'm trying to
    resurrect an old VAX 11/725: that's right, but this dinosaur is giving
    me a lot of problems
    First i had problems with the dead power supply (caused by some
    "rotten" capacitors), then with the melted capstans in the TU58 drive
    (problem solved by using an emulator), now i've got problems with the CPU.

    I had success loading the console tape, but the diagnostics give me
    a lot of trouble: as soon as the software starts, it halt itself
    on the CPU test giving a "BAD CPU" error, and telling me to phone
    the assistance service (hehe, i could try to phone HP and see >:>).
    So, i decided to have another look at the unibus boards (i had already
    polished the contacts on the boards and the backplane, but anyway...)
    and i found out something strange in the installed boards: the M8750
    memory module that would be in slot 6 is missing.
    Here is a photo of the cardcage panel with the default board dispostion
    shown: http://hkzlab.spatof.org/ALBUM/vax-11_725/hpim0261.jpg .

    I don't think that the mem module is optional, anyone can confirm this?
    and... aonyone got spare modules to sell/give away? :-)
    I'd really be happy to get this old system running again!

    Bye everyone, and Happy New Year!
    Hkz

    --
    "La profonda attrazione esercitata da (...) sentirsi parte di una
    potente Elite tecnologica non dovrebbe mai essere sottovalutata."
    -Bruce Sterling
    HKZlab Network: http://hkzlab.spatof.org
    INTERnet -> nightshade@email.it
    Retro DECnet -> 1126::HKZ

  2. Re: VAX 11/725 missing a memory board (M8750)

    Here's the output from the VAX console:

    CONV011
    VERSION 03.00

    UPC=FFFF

    UPC=FFFF


    UPC=FFFF is repeated ad nauseam, until i press send a break.
    It then gets to the ">>>" prompt.
    Using the diagnostic tape:

    >>>T


    **** BEGIN VAX-11/730,725 AUTO TEST ****
    VERSION 1.3 RUN TIME APPROXIMATELY 15:00 MINUTES


    CPU PART 1 TESTING STARTED - RUN TIME = 3:30 MINUTES *FAILED*


    AUTO TEST ABORTED - CPU BAD - CALL FIELD SERVICE

    TYPE 1 TO RETURN TO CONSOLE, 2 TO RESTART AUTO TEST

    Not really encouraging.


    --
    "La profonda attrazione esercitata da (...) sentirsi parte di una
    potente Elite tecnologica non dovrebbe mai essere sottovalutata."
    -Bruce Sterling
    HKZlab Network: http://hkzlab.spatof.org
    INTERnet -> nightshade@email.it
    Retro DECnet -> 1126::HKZ

  3. Re: VAX 11/725 missing a memory board (M8750)

    Hkz,

    I successfully got my old VAX 11/730 (R80/RL02 with TU80 config) running
    OpenVMS Hobbyist 7.3 last winter in time for its 25th anniversary. The poor
    thing has barely enough horsepower & memory to get out of its own way! I
    too suffered through bad power supply components and a TU58 capstan rot. I
    am really surprised the R80 still works. The 730's electonics & mechanicals
    are hobbyist repairable, although I have the field service prints and a
    decent set of spare boards from another 730 system -- which helps! If
    anyone is interested in acquiring this restored antique, let me know... I
    need to recover space in my basement.

    I fixed the TU58 capstans by replacing the degraded rubber with some tygon
    tubing as mentioned here:
    http://www.vintage-computer.com/vcfo...thread.php?t=4
    This fix is acceptable, but I may still try to find some actual TU58
    replacement capstans (some DEC parts companies I contacted wanted $50
    each!).

    Regarding the missing memory board, if you have other M8750 boards in the
    system, move them up to fill slot 6; you need at least one 1 MB memory board
    there to run the system. I have some spare M8750 memory boards available if
    you want to contact me privately.

    Regarding your CPU diagnostics & emulated TU58, are you sure the console is
    loading ALL the CPU microcode properly on power-on? The 730/725 bit slice
    VAX processor will be brain damaged with any bad or missing microcode.

    On a 730/725 with real TU58s, you should see the system spin up the internal
    & external drives trying find CONSLE.EXE on the tapes when powered on.
    After that it should execute the POWER.CMD file on the tape which loads up
    CONSLE.CPU, MMIE.CPU, POWER.CPU and then looks to see what hardware options
    are installed in the system (FPA, R80/RL02 IDC, etc). A returned bit vector
    then determines which CODExx.CMD runs and loads more hardware dependent
    microcode (FP.CPU, FPSP.CPU, BITFLD.CPU, CM.CPU, BASIC.CPU, IRDFPA.CPU,
    QUEUE.CPU and/or IDC.CPU). After that the default boot (DEFBOO.CMD) and
    various other device/diagnostic boot option command files are available.

    I had 3 copies of the V58 microcode console tapes (master & 2 backups, each
    with different bad tape sections) and needed to manually load the microcode
    files (swapping tapes back & forth) to get everything loaded properly. Once
    I got the 730 booted to VMS, I could finally work on piecing together a
    new/good master console tape again with EXCHANGE. I have a VMS EXCHANGE
    image copy of the V58 microcode if you need it.

    Regards,
    Duane D. Krahn
    Wauwatosa, WI USA
    ddkrahn@wi.rr.com



    "Hkz" wrote in message
    news:fl8epg$m68$1@tdi.cu.mi.it...
    > Here's the output from the VAX console:
    >
    > CONV011
    > VERSION 03.00
    >
    > UPC=FFFF
    >
    > UPC=FFFF
    >
    >
    > UPC=FFFF is repeated ad nauseam, until i press send a break.
    > It then gets to the ">>>" prompt.
    > Using the diagnostic tape:
    >
    >>>>T

    >
    > **** BEGIN VAX-11/730,725 AUTO TEST ****
    > VERSION 1.3 RUN TIME APPROXIMATELY 15:00 MINUTES
    >
    >
    > CPU PART 1 TESTING STARTED - RUN TIME = 3:30 MINUTES *FAILED*
    >
    >
    > AUTO TEST ABORTED - CPU BAD - CALL FIELD SERVICE
    >
    > TYPE 1 TO RETURN TO CONSOLE, 2 TO RESTART AUTO TEST
    >
    > Not really encouraging.
    >
    >
    > --
    > "La profonda attrazione esercitata da (...) sentirsi parte di una
    > potente Elite tecnologica non dovrebbe mai essere sottovalutata."
    > -Bruce Sterling
    > HKZlab Network: http://hkzlab.spatof.org
    > INTERnet -> nightshade@email.it
    > Retro DECnet -> 1126::HKZ



  4. Re: VAX 11/725 missing a memory board (M8750)

    Il Mon, 31 Dec 2007 16:01:41 -0600, Duane Krahn ha scritto:

    > Regarding the missing memory board, if you have other M8750 boards in
    > the system, move them up to fill slot 6; you need at least one 1 MB
    > memory board there to run the system. I have some spare M8750 memory
    > boards available if you want to contact me privately.
    >


    Thanks, i contacted you privately as i don't have any mem board,
    and i'm in desperate need for one :-)

    Bye,
    Hkz

    --
    "La profonda attrazione esercitata da (...) sentirsi parte di una
    potente Elite tecnologica non dovrebbe mai essere sottovalutata."
    -Bruce Sterling
    HKZlab Network: http://hkzlab.spatof.org
    INTERnet -> nightshade@email.it
    Retro DECnet -> 1126::HKZ

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