Posts by kataklinger

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Don't Panic. Please wash hands.

  • Another Case of Black Screen

    Hi Jens,


    I checked port pins on CPU responsible for mem. map selection (P0-P2) and all pins are held high (=111) which should select map with both KERNAL and BASIC ROMs mapped as well as I/O area. Please note that I tried several working CPUs, so it cannot be CPU issue.


    I also tested continuity between 6510 pins (P0-P2) and XC95144XL chip and there no problems there, so it's not bad connection/dirty pins.


    Other than that, I tried several firmware versions (the first two and last one), no improvements (the first version did not recognize VICII). I also tired uploading BASIC as extra image (or however it is called) and activating it BASIC ROM, but no luck.


    I'm running out of ideas, and the only conclusion I have is that board is defective and cannot address BASIC ROM and there is issue with joystick/keyboard. :(


    (for CIA test, I don't have access to hardware dongles anymore, so I cannot repeat them)

  • Another Case of Black Screen

    With the help of a friend we performed Diag. Test with its dongles attached to all ports, but it did not yield any improvements with tests. I was expecting PLA/BASIC ROM issues to remain (which they did) but I was expecting other failed tests to pass, but they didn't :(


    The only other cartridge we managed to boot is The Final Cartridge, but computer would not react to joystick/keyboard inputs. CIA chip, known to be working, was placed into CIA #1 slot. The strange thing is that slightly pressing joystick ports (the plastic, not the pins) from top would cause cursor to move erratically :S


    Edit:


    I've inspected the board for physical damages and there are no visible problems, though it is smeared with some stuff on the bottom side. I'll try to clean it tomorrow with alcohol (hope that it won't affect the coloring of the board).

  • Another Case of Black Screen

    Hi Jens,


    I have tried that (moving chips in closed position), but no luck. PSU is the one from you guys.


    Anyways, I had some progress. I put Dead Test and Diag .Test on my U541-II+ and results are attached to this post

    I'm not worried about CIA test as they require hardware connections to actually pass, but test fails for BASIC ROM and PLA consistently.


    Edited as Tobias requested.

  • Another Case of Black Screen

    Hi all,


    I'm having trouble with new MK2 board. As subject says, all I get is black screen. Power LED is solid, board LED is blinking without SID (and is off when there's SID)


    I've removed both CIA chips and SID as well. I have tried three different CPUs (2x6510 and 8500) and four different VICs (2x6569R5, 6569R1 and 6569R3). I also tried cleaning the pins on both chips, but no luck.


    Querying chip info yields following result:


    VIC-II: 6569 (BB 5B AF55 PAL)
    SID 1 : Unknown (11 00)
    SID 2 : Unknown (03 00)
    CPU : PHI2 OK (045E)
    READY (press key for menu)


    I suspect it's something related to CPU/RAM (or maybe ROMs), since I inspected memory where the default screen is located ($0400-$07FF) and I don't see patter one would expect to see when system had booted normally. I inspected content of the ROMs and they seem fine (at least few first and few last bytes of both KERNAL and BASIC ROMs)


    This is the pattern I get in screen memory (I'd expect to see a lot of 0x20 and familiar text for C64 start screen in hex):


    Read memory
    Enter start address in hexadecimal (Type 'X' to abort)?400
    Enter last address in hexadecimal (Type 'X' to abort)?7FF
    6A 85 6A A9 69 A0 00 20 FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    5B BC AA 4C 61 B0 A9 00 FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    85 0D C6 4D 20 A6 B6 85 FF FF FF FF FF FF FF FF


    So do you have any more suggestions?


    Thanks!


    Regards,

    Mladen