Region free BIOS for MEGA-CD Version 2.00

Discussion in 'Sega Discussion' started by l_oliveira, Oct 25, 2014.

  1. Bad_Ad84

    Bad_Ad84 The Tick

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    Hes trying to stack bioses. If hes not wired it up properly (/CE pulled high on original chip, /CE low on new one, but not connected together) it will give a black screen.

    There is no problem with the bios, I use the same file for all I burn and they work fine.

    Needs pics of what's been done to give any answers.
     
    Last edited: Feb 2, 2017
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  2. marcushg

    marcushg Member

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    Sorry to bother, i suppose it's just that something is not making contact. (one thing i noticed is that the sticker was upside down, but i just look to the little notch on one side as guide)
    I was using 1k resistors coming from pin 1 (and making contact with leg 20 from one and other bios). Tried another approach (soldering an IDE cable split in two) and soldering to the legs of the original bios, and same result... black screen. so i suppose maybe one of the cables or something is bridging or not making contact. the problem is that i don't have a multimeter for checking... so i think i have to try again to unsolder the original bios, but looks impossible with my soldering iron and pump (really cheap ones).
    I already broke one of the burned eproms (lucky i had two of them)
     
  3. Bad_Ad84

    Bad_Ad84 The Tick

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    Where are you located?

    Might make more sense to send me the board and I'll fit a socket for you.
     
  4. marcushg

    marcushg Member

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    wow that would be great but i'm in spain so i suppose too high shipping costs... i'll just find someone around to help or buy proper equipment. Even with that do you think following guide should work? youtube.com/watch?v=HkwrsUJ7Idk
    read on some forum that maybe 1k resistors were too low. thanks for everything!!!
     
  5. FACE666

    FACE666 Member

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    hello there.can anyone help me?i like to buy to Eprom already burn with all the bios so i can install on my mega cd 2.tks
     
  6. smoke monster

    smoke monster Rapidly Rising Member

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    Are the EverDrives still affected by the bios issue? I can't test myself, but Krikzz posted about fixing a major glitch a while back. I have no idea if it's the same bug being discussed here. If not, I could report it to Krikzz to see if he'll look at it. Any details that you guys could provide would help in that case.
     
  7. l_oliveira

    l_oliveira Officer at Arms

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    smoke monster and MonkeyBoyJoey like this.
  8. TennokoeJames

    TennokoeJames Active Member

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    Hi l_oiveira

    Firstly I would like to thank you for your stirling work.
    I have been using your region free Sega CD2 bios with my everdrive without issue for months and it has been great.

    I recently bought a mint Wondermega M2 and am now having issues however, so I thought I would let you know to see if you have any ideas:

    When I try to load the correct bios I either get a freeze on a black screen, or the Wondermega splash screen appears and freezes.
    I have tried downloadng it again and checking the archive for corruption but it appears clean.
    I can use your region free Sega/MegaCD2 bios' with my system and they work, but they have an issue:
    Whenever loading initiates in a game, there is a split second burst of static.
    This is probably due to the Wondermega systems, though still single speed, having a faster pickup transit (so I've read) so the audio doesn't get muted in time.

    Have you any idea why the region free M2 bios would not be working via everdrive X7 (latest hw revision)?
    It's not the end of the world, as I can still use the CD2 bios, but any help would be awesome.

    Many thanks!
     
  9. l_oliveira

    l_oliveira Officer at Arms

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    Can you provide me with a dump of your original M2 BIOS? There might be more than one version of it and also, I can't vouch for the accuracy of the dump I patched as I got it from the internet.

    I actually tested it on a CD2 unit and it did run but due to hardware differences the CD-DA (audio tracks) muting behavior was inverted (muting on when playing audio so no audio was played and noise played when one tried to play the data track as audio).
     
  10. TennokoeJames

    TennokoeJames Active Member

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    How do I dump my original bios?
     
  11. l_oliveira

    l_oliveira Officer at Arms

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  12. TennokoeJames

    TennokoeJames Active Member

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    Popping the bios out sounds like a big no-no for me.

    Thanks for the link, but I think PC parallel ports have gone the way of the dinosaur.
    I certainly haven't got a machine with one.

    I'll ask krikzz on the Everdrive forums if he made a tool that can do this via the Everdrive usb socket.

    Otherwise I think I'm sunk. Lol
    Thanks for getting back to me. I'll let you know what I find out.
     
  13. Bad_Ad84

    Bad_Ad84 The Tick

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    If you have a proper desktop, you can buy a PCI or PCI-E parallel port for cheap enough.
     
  14. TennokoeJames

    TennokoeJames Active Member

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    I have 3 laptops and a little media center box. Lol
     
  15. TennokoeJames

    TennokoeJames Active Member

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    OK I have asked the question on the Everdrive forums.

    When I boot my Wondermega using its internal bios it says that it is v2.00 in the corner.
    What version is the region free one?
    Has anyone had it working?

    Thanks again, guys.

    Edit:
    Hold on a second.. I just noticed something weird.
    After using the Everdrive menu to launch the internal bios of the Wondermega, a new 'CD BIOS.BIN' file has appeared in the Everdrive system folder. 128kb in size.
    And when I boot that (just like I would the CD2 bios I was using) it takes me to the Wondermega menu.

    Maybe the Everdrive dumps the cd bios when you choose to load the systems internal bios.
    That would be laughably easy. Lol
    I'll put the file in here.
     
    Last edited: Aug 27, 2017
  16. TennokoeJames

    TennokoeJames Active Member

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    Here is the file.
    It does actually appear to be a dump of the internal bios. :)
     

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  17. Bad_Ad84

    Bad_Ad84 The Tick

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    I can relate, I ditched my desktop years ago. But my laptop has expresscard slot (which you could use) and a dock with serial/para too.

    Made sure I covered my bases before ditching the desktop :)
     
  18. TennokoeJames

    TennokoeJames Active Member

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    I never was much of a planner. Lol
     
  19. l_oliveira

    l_oliveira Officer at Arms

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    The file you uploaded is 1:1 identical to my patched BIOS named "WONDERMEGA-G303_regfree.BIN" minus the patches, of course.
     
  20. l_oliveira

    l_oliveira Officer at Arms

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    Does your CDBIOS.BIN file loads correctly?
     

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