P112 Debug Help, Please - CP/M

This is a discussion on P112 Debug Help, Please - CP/M ; First, a big public thank you to Dave Griffiths for putting this kit together. Beautifully kitted and really well documented. I haven't had this much fun, probably, since Heathkit folded. Got my board assembled and to my utter astonishment it ...

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Thread: P112 Debug Help, Please

  1. P112 Debug Help, Please

    First, a big public thank you to Dave Griffiths for putting this kit
    together. Beautifully kitted and really well documented. I haven't
    had this much fun, probably, since Heathkit folded.

    Got my board assembled and to my utter astonishment it actually did
    something right away :-).

    What I see on the console, with no drive plugged in, is the first three
    lines of the boot banner:

    SMC...
    ROM...
    RAM...

    Then, I see a bunch of complaints about unrecognizable disk format.
    Then, the board resets and I see the original three lines again.
    Lather, rinse, repeat.

    If I hit a bunch of times at the right time I can see the
    debugger's "=" prompt, but then the board resets almost immediately.

    Anybody have any ideas what I can try next? Thanks.

    -Dave


  2. Re: P112 Debug Help, Please

    Dave wrote:
    > First, a big public thank you to Dave Griffiths for putting this kit
    > together. Beautifully kitted and really well documented. I haven't
    > had this much fun, probably, since Heathkit folded.


    Thanks!

    > Got my board assembled and to my utter astonishment it actually did
    > something right away :-).


    > What I see on the console, with no drive plugged in, is the first three
    > lines of the boot banner:


    > SMC...
    > ROM...
    > RAM...


    > Then, I see a bunch of complaints about unrecognizable disk format.


    This is exactly what you should get given no drive is attached and you
    haven't set the NVRAM. Normal behavior is to complain ten times, then
    show the debugger's prompt.

    > Then, the board resets and I see the original three lines again.
    > Lather, rinse, repeat.


    > If I hit a bunch of times at the right time I can see the
    > debugger's "=" prompt, but then the board resets almost immediately.


    > Anybody have any ideas what I can try next? Thanks.


    1)
    The green wire on the power cable is intended for a soft-reboot switch.
    Grounding the wire causes a soft reboot. Make sure the bare end of that
    wire is insulated.

    2)
    Make sure you have the jumpers in the correct positions. I made this
    mistake myself several times.

    3)
    Make sure the resistor packs aren't backwards. I've been told this can
    cause what you're seeing, but I haven't done it myself.

    4)
    Go over the board carefully looking for solder bridges. Because the
    components are packed so closely, chances are greater that this may
    happen. The expansion connector is especially prone to bridges because
    it's hard to get an iron in there. I soldered that by heating the pins
    as far down as I could, then apply solder until liquid solder flowed
    into the hole. Often this resulted in big blobs. No problem! Hold the
    board solder-side down and touch connections with a hot iron to draw off
    excess solder, then knock the accumulated solder off the iron into a
    coffee can.



    --
    David Griffith
    dgriffi@cs.csbuak.edu <-- Switch the 'b' and 'u'

  3. Re: P112 Debug Help, Please

    Well, in my quest for instant gratification I started testing the board
    without installing the bypass caps. Bad idea. Also, the docs I think
    are contradictory on the setting of jumper P12. The picture on page 12
    doesn't seem to match the text on page 44. If installed per page 12,
    my system just hangs.

    Anyway, I got it to boot, once. Since then, I'm back to the
    "unrecognizable disk format" deal. I made a new disk using rawrite but
    still have the same problem. Both disks were write protected.

    Any ideas on how to proceed are highly appreciated.

    Thanks.

    -Dave


  4. Re: P112 Debug Help, Please

    On 4 Feb 2006 11:53:04 -0800, "Dave" wrote:

    >Well, in my quest for instant gratification I started testing the board
    >without installing the bypass caps. Bad idea. Also, the docs I think


    Bad it's worse than that. All that logic switching creates noise and
    will be bad juju for successful operating.

    >are contradictory on the setting of jumper P12. The picture on page 12
    >doesn't seem to match the text on page 44. If installed per page 12,
    >my system just hangs.
    >
    >Anyway, I got it to boot, once. Since then, I'm back to the
    >"unrecognizable disk format" deal. I made a new disk using rawrite but
    >still have the same problem. Both disks were write protected.
    >
    >Any ideas on how to proceed are highly appreciated.
    >
    >Thanks.
    >
    >-Dave


    One do not power up or down with media in the drive. Sometimes you
    write crud to the disk before system has asserted control or as it's
    going down. Common source for "it booted once then stopped".

    Is the drive good and connected properly, also is there a good hard
    ground connecting the drive to the P112?

    Is the PS adaquate and well regulated? Converse if it's a switchmode
    PS is there enough load to insure stable regulation?

    One last thing, most of the devices are CMOS or similar technology and
    ESD aka lightining is bad for it.


    Allison

  5. Re: P112 Debug Help, Please


    "Dave" wrote in message
    news:1139082784.457995.64800@g47g2000cwa.googlegro ups.com...
    > Well, in my quest for instant gratification I started testing the
    > board
    > without installing the bypass caps. Bad idea. Also, the docs I
    > think
    > are contradictory on the setting of jumper P12. The picture on page
    > 12
    > doesn't seem to match the text on page 44. If installed per page
    > 12,
    > my system just hangs.


    Mine is installed on pins 2-3 - works fine.

    > Anyway, I got it to boot, once. Since then, I'm back to the
    > "unrecognizable disk format" deal. I made a new disk using rawrite
    > but
    > still have the same problem. Both disks were write protected.


    Without a disk in the drive, the 'Unrecognized Disk Format' message
    will appear ten times and then the P112 will fall back to debug. If
    you press any key, it should abort the 'x10' loop and fall back to the
    debugger.

    If you're getting this message with the disk installed, then either
    the disk is bad (such as no operating system) or you've installed
    something wrong, such as the floppy cable - very easy to do. Pin 1
    (red stripe) on floppy connector P9 is next to the P112 power plug at
    P6. Also, ensure you're using the primary floppy port at P9 vice the
    secondary port at P10.

    As Allison said, don't power up or down with a disk in the drive - it
    can damage the disk data or format.


    --
    Terry



  6. Re: P112 Debug Help, Please

    Thanks, all, for your help.

    I think the cabling, PS, etc. are OK since I booted just fine once.

    Not sure how the disk could've been hosed because the write protect tab
    was set. Also, I made a new disk using rawrite.exe on
    \zsdos\zs113005.img and got the same results. Am I doing the right
    thing to get a "clean" boot disk?

    Also, my issue with P12 is that on page 12 of the docs the drawing
    shows pins 1-2 jumpered whereas everywhere else in the docs it says
    2-3.

    Thanks.

    -Dave


  7. Re: P112 Debug Help, Please


    "Dave" wrote in message
    news:1139110296.428921.166080@o13g2000cwo.googlegr oups.com...
    > Thanks, all, for your help.
    >
    > I think the cabling, PS, etc. are OK since I booted just fine once.


    And then you took it all apart to install the bypass caps - I assume.
    Didn't you? Then, I further assume, you put it back together and then
    started getting the 'Unrecognizable Disk' error.

    > Not sure how the disk could've been hosed because the write protect
    > tab
    > was set.


    That only prevents the controller from writing to the disk. It does
    not prevent spurious surges during power up/down as Allison noted.

    > Also, I made a new disk using rawrite.exe on
    > \zsdos\zs113005.img and got the same results. Am I doing the right
    > thing to get a "clean" boot disk?


    Yes.

    > Also, my issue with P12 is that on page 12 of the docs the drawing
    > shows pins 1-2 jumpered whereas everywhere else in the docs it says
    > 2-3.


    As I said, mine is on 2-3 and works fine. Yes, the docs are
    contradictory. Position 1-2 supplies +5v to the /WE pin on the Flash
    RAM, preventing writes to the Flash. Position 2-3 supplies the /WR
    signal to the /WE pin, allowing you to write to it in place. Frankly,
    it shouldn't even matter which position P12 is in, although I
    recognize that you said your machine locks up in postion 1-2.


    > Thanks.


    Always willing to help. We can take this to e-mail for further
    assistance if you desire.

    --
    Terry



  8. Re: P112 Debug Help, Please


    Terry Gulczynski wrote:
    > "Dave" wrote in message
    > news:1139110296.428921.166080@o13g2000cwo.googlegr oups.com...
    > > Thanks, all, for your help.
    > >
    > > I think the cabling, PS, etc. are OK since I booted just fine once.

    >
    > And then you took it all apart to install the bypass caps - I assume.
    > Didn't you? Then, I further assume, you put it back together and then
    > started getting the 'Unrecognizable Disk' error.
    >


    Nope, not correct. The caps were installed. It simply booted once
    then the next day wouldn't boot again.

    > > Not sure how the disk could've been hosed because the write protect
    > > tab
    > > was set.

    >
    > That only prevents the controller from writing to the disk. It does
    > not prevent spurious surges during power up/down as Allison noted.
    >


    OK, that's something I didn't know. I was powering up with the disk in
    the drive.

    > > Also, I made a new disk using rawrite.exe on
    > > \zsdos\zs113005.img and got the same results. Am I doing the right
    > > thing to get a "clean" boot disk?

    >
    > Yes.
    >


    Then my fresh disk should boot OK? (doesn't)

    > > Also, my issue with P12 is that on page 12 of the docs the drawing
    > > shows pins 1-2 jumpered whereas everywhere else in the docs it says
    > > 2-3.

    >
    > As I said, mine is on 2-3 and works fine. Yes, the docs are
    > contradictory. Position 1-2 supplies +5v to the /WE pin on the Flash
    > RAM, preventing writes to the Flash. Position 2-3 supplies the /WR
    > signal to the /WE pin, allowing you to write to it in place. Frankly,
    > it shouldn't even matter which position P12 is in, although I
    > recognize that you said your machine locks up in postion 1-2.
    >


    Yes, I can't explain this either but it is so on my board.

    >
    > > Thanks.

    >
    > Always willing to help. We can take this to e-mail for further
    > assistance if you desire.
    >


    Sometimes a public forum is preferable so others may benefit. But,
    email is fine since I'm stuck and need help from more experienced
    folks.

    > --
    > Terry



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