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Thread: Commodore pet 3032 screen full of lines

  1. Default

    Update:

    Uh2:

    12 high
    13 low

    uh3:

    12 low
    13 high

    ug1:

    9 high
    13 low

    uh1:

    1 high
    3 oscill
    5 high
    6 low

  2. #362
    Join Date
    Jun 2012
    Location
    UK - Worcester
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    Default

    I like those signals better - as UH2 pins 13 and 12 are now acting as a 'proper' inverter!

    I think you ought to get a replacement 74164 to replace UH3 next.

    Dave

  3. Default

    Quote Originally Posted by daver2 View Post
    I like those signals better - as UH2 pins 13 and 12 are now acting as a 'proper' inverter!

    I think you ought to get a replacement 74164 to replace UH3 next.

    Dave

    Ok Daver2,
    it is useless try to turn on now right?

  4. #364
    Join Date
    Jun 2012
    Location
    UK - Worcester
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    Default

    You can turn it on.

    Remove the NOP generator and see what my PETTEST does...

    Don't be surprised if it fails in the same way though...

    Since we may have fixed one problem (the potentially faulty 74S04) the fault symptoms may present themselves ever so slightly differently?

    Dave

  5. Default

    Quote Originally Posted by daver2 View Post
    You can turn it on.

    Remove the NOP generator and see what my PETTEST does...

    Don't be surprised if it fails in the same way though...

    Since we may have fixed one problem (the potentially faulty 74S04) the fault symptoms may present themselves ever so slightly differently?

    Dave

    Im a desperate Italian mr Daver2
    I've tried to turn on but it's always same thing....

    I try to order 164 now...

  6. #366
    Join Date
    Jun 2012
    Location
    UK - Worcester
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    Default

    That's what I said. I think the 164 is kaput - hence swapping any other device other than the 164 won't cure your problem (although I think there is a small probability that the 74S04 may have been faulty as well - unless the change of technology from 'S' to 'F' has made things appear to work as far as the logic probe indications are concerned).

    If it was the 164 all along - all our previous work has been for nothing!

    Dave

  7. #367

    Default

    I've not been following closely but I think when using the logic probe on the 164 higher bits we saw some static bits.
    Dwight

  8. #368
    Join Date
    Jun 2012
    Location
    UK - Worcester
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    Default

    Yep,

    The last two bits of the 164 shift register appear to be stuck at '0' and '1' respectively.

    Having changed the inverter in the output of 164 QG, things didn't improve, hence it is not being 'dragged' low.

    That's where we currently are...

    Dave

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