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Thread: 5150 Not Passs Mem Refresh Test

  1. #31
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    The Supersoft/Landmark diagnostic is known to be misleading in regard to RAM tests, especially for the 16KB-64KB motherboard. Per the 16KB-64KB motherboard specific information at [here], "Under no circumstances, believe that a failure of the '16K CRITICAL MEMORY REGION' test must mean that a chip/s in RAM bank 0 has failed." So, you ignore what the Supersoft/Landmark diagnostic is telling you.

    As for Ruud's diagnostic, up until today, I have only ever run it once, and that was an early version. I have just now pulled out a fully functional 16KB-64KB motherboard from storage, and obtained the latest version of Ruud's diagnostic. Based on what I am seeing the diagnostic display as I selectively remove and reinsert various RAM chips, your bank 0 is now good. The problem now is related to bank 1 (possibly an addressing issue as suggested by Dwight).

    If your bank 0 is now good, as I believe it is, you should see the motherboard start after you have refitted the IBM BIOS chip (assuming that chip is good). Does it start ?

  2. #32
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    Quote Originally Posted by modem7 View Post
    Based on what I am seeing the diagnostic display as I selectively remove and reinsert various RAM chips, ...
    Some (partial) screen shots are at [here].

  3. #33
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    Thanks modem7
    In that link just above, I get on my screen what is shown on the third picture. It looks like all ram chips are removed. But they are all there.
    I installed back the 10/27/82 rom, and booted. I get 0455 201. I guess I still have bad ram. I still have 4 chips to replace.
    I also get FC00 ROM - bad cassette basic rom chip. I pulled it and cleaned the pins and still get the same. I guess I need another. But this one is gold covered ceramic one. I bet those are harder to find.
    Atari Falcon030, Atari MSTE, Atari PS3000, STACY 4, 4160STE-CosmosEX, Atari PC1, 400/800/1200XL,800XL,800XE,130XE, XEGS, Apple IIGS, TRS-80 4P, TI 99/4A, Co-Co 3, Amiga 500, C64/128D

  4. #34
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    Perhaps I should fill all banks and see what error I get rin 1027/82 rom in?
    Atari Falcon030, Atari MSTE, Atari PS3000, STACY 4, 4160STE-CosmosEX, Atari PC1, 400/800/1200XL,800XL,800XE,130XE, XEGS, Apple IIGS, TRS-80 4P, TI 99/4A, Co-Co 3, Amiga 500, C64/128D

  5. #35
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    Well, shucks,
    I fill all the ram and it boots with ram errors!!!
    Lots of work, and knowledge gained. Still have the FC00 ROM error. Where can I find a rom image I can burn to an eprom?
    Again many many thanks for all the help and hand holding on this and other threads. It's fun and frustrating at the same time.
    Atari Falcon030, Atari MSTE, Atari PS3000, STACY 4, 4160STE-CosmosEX, Atari PC1, 400/800/1200XL,800XL,800XE,130XE, XEGS, Apple IIGS, TRS-80 4P, TI 99/4A, Co-Co 3, Amiga 500, C64/128D

  6. #36
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    Quote Originally Posted by KLund1 View Post
    Well, shucks,
    I fill all the ram and it boots with ram errors!!!
    I am sure that you meant "no RAM errors".

    Quote Originally Posted by KLund1 View Post
    Lots of work, and knowledge gained. Still have the FC00 ROM error. Where can I find a rom image I can burn to an eprom?
    FC000 = BASIC chip U32. There are couple of BASIC sets at [here].

  7. #37
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    Yes, too excited to type well.
    NO ram errors!!!
    Atari Falcon030, Atari MSTE, Atari PS3000, STACY 4, 4160STE-CosmosEX, Atari PC1, 400/800/1200XL,800XL,800XE,130XE, XEGS, Apple IIGS, TRS-80 4P, TI 99/4A, Co-Co 3, Amiga 500, C64/128D

  8. #38
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    Quote Originally Posted by KLund1 View Post
    Yes, too excited to type well.
    And you have the satisfaction of fixing another motherboard.

    Having a quick look back through the posts, the root cause is multiple bad RAM chips in bank 0. Do you agree? I will add the motherboard failure to the list at [here].

  9. #39
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    I think Yes (minus the FF00 error). That is probably true after re-reading the Supersoft bugs. These early boards, as you well know, are hard to diagnose. I would suggest that when the SuperSoft results changed from bits 3 & 6 in error to all all bits in error is when the board probably was working. But I kept removing and socketing additional ram chips.
    To test that correctly I probably would have to refill all ram after each new socket/ram IC after it was soldered in. If I recall, after I changed 3 & 6 is when all bits 'went bad' in Supersoft. And RUUD's was about to move past the first 16k test. So maybe a small foot note in your MOST EXCELLENT minuszero site about this issue might be of use to others.But you get all credit for this fix. I was just the hands doing the directed work

    I am still working on the FC00 error. Possibly more questions...
    Atari Falcon030, Atari MSTE, Atari PS3000, STACY 4, 4160STE-CosmosEX, Atari PC1, 400/800/1200XL,800XL,800XE,130XE, XEGS, Apple IIGS, TRS-80 4P, TI 99/4A, Co-Co 3, Amiga 500, C64/128D

  10. #40
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    Quote Originally Posted by KLund1 View Post
    But you get all credit for this fix.
    There were a few contributors. A 'thank you' to Rudd for his diagnostic, an additional tool to assist in regard to RAM issues, particularly given that the RAM component of the Supersoft/Landmark diagnostic is unreliable against a 16KB-64KB type motherboard.

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