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Type: Posts; User: Dwight Elvey

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  1. I see no reason why not. Dwight

    I see no reason why not.
    Dwight
  2. Maybe you could dump the bios and the OP could...

    Maybe you could dump the bios and the OP could blow an EPROM and attach it to his board.
    Dwight
  3. I made a debug board to help diagnose KIM-1...

    I made a debug board to help diagnose KIM-1 boards. My main purpose was to determine if one of the 6530 had failed. One had so I made a really small 6532 replacement, similar to Ruud's boards but...
  4. The Polymorphic machine does not know about...

    The Polymorphic machine does not know about keyboard scans. If you look at the Polymorhic video schematic, you'll see that the keyboard input is connected to an interrupt. The machine waits for a key...
  5. I'm mostly sure there was no blink circuit. I...

    I'm mostly sure there was no blink circuit. I don't recall a reverse video either.
    Dwight
  6. There is a known timing error in the vertical...

    There is a known timing error in the vertical retrace of the Polymorphic board. It causes a small amount of compression of the first line. It is more annoying than a real problem and it depends on...
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    Hi Dave At address 75 is the input routine....

    Hi Dave
    At address 75 is the input routine. I've got that relatively worked out. The serial input returns as a byte in RE and RF with MSBs in RE.
    I've not looked to much at the PRINT routine but...
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    That is what I thought. That is why I asked. In...

    That is what I thought. That is why I asked. In order to make sense of the data, you'd need to invert everything. I do have the EPROM file split up as well as one single large file, with all 4...
  9. Did you do any of the voltage checks I suggested?...

    Did you do any of the voltage checks I suggested?
    Dwight
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    Before I go farther I'd like to describe what I...

    Before I go farther I'd like to describe what I have and are working with. The PMOS uses inverted level for the physical EPROMs. This means that logical address 0 starts at the physical address of...
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    Do you want binary or hex? One file or 4 files?...

    Do you want binary or hex? One file or 4 files?
    Partial disassembled?
    I've not seen the code anywhere on line.
    I have the files address and data inverted, as it was originally for PMOS levels. It...
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    I'm not sure what you mean that LEDs should have...

    I'm not sure what you mean that LEDs should have no measurable resistance. In back voltage the current should be almost 0, meaning infinite resistance. In the forward direction, it depends on the...
  13. When you have a mother board with a bios, you...

    When you have a mother board with a bios, you don't want to install the onboard bios. I can't tell you why your particular system may or may not work with this card. It may be that the card does not...
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    Many series stringed likes are designed to fail...

    Many series stringed likes are designed to fail shorted, if the light opens. The wires a feed with a constant current source. If the light doesn't allow current to pass, the voltage across that light...
  15. One side it the emitter and the other side is the...

    One side it the emitter and the other side is the detector. There are usually 4 terminals. There are usually two on each side of the wheel.
    Dwight
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    I thought I'd refresh this. I'm especially...

    I thought I'd refresh this. I'm especially interested in a copy of the native Intel 4004 assembler, that was written by Tom Pittman. I have a copy on EPROM but I regret that the last EPROM has...
  17. The auto-save doesn't always work either. I try...

    The auto-save doesn't always work either. I try to remember to put the entire message in the paste buffer before posting. That way, the MB software isn't involved. Just consider it part of the...
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    NiCads have a serious issue when used more than...

    NiCads have a serious issue when used more than one in series. If you reverse current them ( one cell finishes before the other ) the depolorizers, that convert the outgassing from charging, are on...
  19. There were a couple things I remember about XT...

    There were a couple things I remember about XT controllers and later AT controllers. I used a XT controller with my NC4000 computer. It is not a x86 processor, it is a stack processor. It would just...
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    I agree. No circuit board will last long with...

    I agree. No circuit board will last long with power and being underwater. Conformal coat will help but even that shouldn't be underwater when powered.
    There is not much that can be done about...
  21. Most memory test are only look to see if the...

    Most memory test are only look to see if the location can read and write. Address faults can go untested. Early on, many used GALPAT but it grows in exponentially with memory size. Then "March C" was...
  22. RS232 got messed up by a number of applications....

    RS232 got messed up by a number of applications. Some uses don't need or use hand shake. Male and female connectors get mixed up. Not all follow the rules. I tend to ignore what it is suppose to be...
  23. You may still need to rewire some. It could be...

    You may still need to rewire some. It could be straight through or need a null modem. It always helps to have a RS232 breakout box to crisscross the wires as needed to make both ends happy.
    Dwight
  24. Other than common text functions like home, clear...

    Other than common text functions like home, clear screen, CRLF and scroll. Locating to an XY is about all that is need, that I can think of.
    Dwight
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    I'm not a Pet expert but the fact that is waits...

    I'm not a Pet expert but the fact that is waits to see a key pressed to bring on the signon, leads me to think the computer is seeing a constant key press or something. Maybe related to an interrupt....
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