Cybiko Repair-A-Thon - Part 2 - Serial Debugging

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  • เผยแพร่เมื่อ 27 ธ.ค. 2024

ความคิดเห็น • 13

  • @dregenius
    @dregenius 11 หลายเดือนก่อน +1

    I got a launch model like... a week ago, that has the same symptoms as your green launch - black screen and, after soldering a makeshift serial connection to the test points on the board (and later using a friend's original serial cable), the same -5 of 0 blocks error in the debug console. Corrosion was similar to, maybe even a little less aggressive than your green launch, but I'm following *CLOSELY* to see what happens. The fact that you just posted this within days of me getting a Cybiko... the device I missed out on as a child, is superb timing lol

    • @RobertsRetro
      @RobertsRetro  11 หลายเดือนก่อน

      The thing that still perplexes me is that there are fairly large differences between the launch model and later revision and yet they all seem to have the same black screen and negative of 0 blocks error. So if it was battery damage, how can it be affecting all 3 the same way? At this point I am thinking the flash chips may just be bad and need replacing but this is some extra-fine SMD work. Stay posted for part 3!

    • @dregenius
      @dregenius 11 หลายเดือนก่อน

      @@RobertsRetro I am GLUED to my TH-cam notifications lol! Do both revisions use the same flash chip? I think my friend's soft-power model uses the same chip as my switched model. If it's the serial or control lines or even some failure mode with the chips themselves I can see that explaining why both revisions have the same issue?

    • @RobertsRetro
      @RobertsRetro  11 หลายเดือนก่อน

      Yeah it's the same SPI (File Flash) chip, in Part 3 (th-cam.com/video/xpGBSzW4T5Y/w-d-xo.html) I take a look at some of the hardware differences. The later soft-power models have an additional parallel (not SPI) flash where the actual CyOS file lives. So the soft-power models actually have two flash chips, one SPI (File Flash), same as the launch models, and another Parallel (CyOS) flash that replaces one of the 256K SRAM chips.

  • @drfrancintosh
    @drfrancintosh 10 หลายเดือนก่อน

    I seem to remember there was a serial.dl file you had to install on your cybiko for the serial port to work.

  • @dregenius
    @dregenius 11 หลายเดือนก่อน

    I'll second the issue on most of these being hardware related... when I saw the debug messages on mine, it definitely looked like a flash memory issue. What's interesting is that uploading to the flash seems to work - loading various system updates seems to complete with serial output that indicates whatever CPU handles the serial and flash was happy with the transfer, but the moment the unit tries to boot, it sees 0 blocks. Do we know if the chip that does the flash programming is actually the CPU? If it's not, that may explain the behavior - broken traces between the flash and the CPU... or maybe a write pin on the flash chip has a broken trace? I looked up the datasheet for the flash and it's a serial interface, not parallel so should be slightly easier to put the scope on, but I don't think my old Tek is really fast enough for this job lol... just thinking out loud don't mind me lol.

    • @RobertsRetro
      @RobertsRetro  11 หลายเดือนก่อน

      Based on the schematics the SPI File Flash is connected to the CPU only, there is a small circuit between the Serial port and the CPU but this appears to be mostly for level shifting. There is a ROM boot loader in the CPU (really an SOC) that handles the flashing process. The datasheet for the CPU (HD6472246) actually seems to mention the ROM on the CPU could be updated as this lines up with the ZTAT version but I haven't dug into this deeper. I plan to get the scope on the SPI pins to the File Flash (AT45DB041A) and see if there is proper activity. Helpfully I have one working unit I can compare with.

  • @TheWolf12976
    @TheWolf12976 10 หลายเดือนก่อน

    And how meny extension cartriges do you have i can not find any on the Internet

  • @TheWolf12976
    @TheWolf12976 11 หลายเดือนก่อน

    I have a cybiko i brought it the otherday and i just checked the main bord for crosians and bridges and i think i got a is issue so do you know where i can get or build a connector for the cybiko?

    • @RobertsRetro
      @RobertsRetro  11 หลายเดือนก่อน

      As far as I know, the serial connector on the Cybiko is unique and/or unobtainium. If you can't find the cable, I'd suggest soldering to the 4 pins of the connector inside the Cybiko. Search for "Dealing with a Cybiko Classic in 2022" on kn100's page as they have found the test points on the main board that will make the soldering a bit easier. Otherwise there is nothing special about the serial cable, it is just a straight-through connection.

    • @TheWolf12976
      @TheWolf12976 10 หลายเดือนก่อน

      I just figured out the error the soc chip is bad that is why it is not booting up but i think it is possible to put a micro usb cable on the cybiko data port the micro usb conector has 5 pins but the conector has 4 so it is possible that it can be soldierd on easily and some wires to connect directly at the sco chip aka hipachi h8s/4421 prosseser

    • @RobertsRetro
      @RobertsRetro  10 หลายเดือนก่อน

      Do you have any detailed information about why the SOC/CPU is bad in your unit? Wondering if that may be the case for mine as well, just really strange it's happened to 3 of my units. The connector on the Cybiko is for standard RS232 Serial, so it is not directly compatible with USB. Though you could use a USB to Serial cable like for the Arduino. Also if you have any info on the utilities for the H8S processor that would be great. There was some mention in the datasheet for the HD6472246 that this may even have the ZTAT flash that can be updated though I have not confirmed this is the case.

    • @TheWolf12976
      @TheWolf12976 10 หลายเดือนก่อน

      Ok ps i think it is a internal error