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Thread: Trs 80 model 4 dead

  1. #21
    Join Date
    May 2013
    Location
    Williamstown Victoria Australia
    Posts
    389

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    Its the only one i could find that had 1 Xtal.
    Oh well.

    Ray
    If it ain't Broke then PLEASE DONT fix it.
    Procrastinators Unite.
    I keep telling you I am Not Pedantic.

  2. #22

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    Make sure that reset isn't stuck down... what you describe sounds familiar to my experience.

  3. #23

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    Quote Originally Posted by embpic View Post
    Very nice! I see you have the two crystal board which I believe is a REV A board. If you guys were watching eBay recently you probably saw a 128K mainboard for a model 4 that had overheating problems. Yup, I bought it. By looking at it very closely I could tell that it was also a REV A board with two crystals. I am hoping that between my old board and the new one I will be able to get it going. At least with a REV A board I will have the schematics!

    Sean
    Is that Rev A schematic available publicly someplace? If so, could you post a link? I don't need it right now, but chances are I will someday.

  4. #24

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    Quote Originally Posted by lanmangler View Post
    Make sure that reset isn't stuck down... what you describe sounds familiar to my experience.
    The reset switch is not stuck down. I have checked the reset switch at the reset pin on the Z80 and it works like it should.

  5. #25

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    Quote Originally Posted by Paradroyd View Post
    Is that Rev A schematic available publicly someplace? If so, could you post a link? I don't need it right now, but chances are I will someday.

    https://www.google.com/url?sa=t&rct=...kxWZ7kqlUP4vfj

  6. #26

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    Very nice! Thanks!

  7. #27

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    I have a bag of crystals that are at the frequency for a Model 4, however they are not oscillators. I'd be willing to mail you one of them to try.

    When my oscillator failed, it went flatline after it got warm. Smallest order I could get of a full can programmed at that speed was 500, and that was way too many.

  8. #28

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    Quote Originally Posted by embpic View Post
    Very nice! I see you have the two crystal board which I believe is a REV A board. If you guys were watching eBay recently you probably saw a 128K mainboard for a model 4 that had overheating problems. Yup, I bought it. By looking at it very closely I could tell that it was also a REV A board with two crystals. I am hoping that between my old board and the new one I will be able to get it going. At least with a REV A board I will have the schematics!

    Sean
    I saw that one and thought about this thread.

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