Region free BIOS for MEGA-CD Version 2.00

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

  1. l_oliveira

    l_oliveira Officer at Arms

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    Patching code was standardized. Now all BIOS files use very similar patches.

    A new function was added to USA and EU BIOS (all versions) which allow you to skip the SONIC/SEGA logo by holding the "C" button on 1P controller.
    The capability of booting from cartridges through the CD BIOS (apply only to USA and EURO BIOSes) is now restored and should work work exactly as it did with the original BIOS.

    Japanese/ASIA BIOS were re-patched to make them comform with the patching style used on the USA and EURO BIOS files.

    Included on the package are all BIOS files I could find dumped.

    If you guys have anything I don't and want it patched, let me know.


    Commemorative post ! ;)

    Edit: I do not support the use of any of these with Everdrive MD or Mega Everdrive due to a design problem with the Everdrives.

    Edit2:
    Aaaaand here's the region free BIOS for LaserActive.

    Special thanks to veggav(https://assemblergames.com/members/fandangos.68204/) for providing me with a LaserActive unit and TabajaraLabs(https://assemblergames.com/members/tabajaralabs.88579/) for providing me with a PAC S-10 unit that allowed me to test it in a practical way.
     

    Attached Files:

    Last edited: Aug 11, 2017
  2. Druidic teacher

    Druidic teacher Officer at Arms

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    x
     
    Last edited: Jun 22, 2017
  3. l_oliveira

    l_oliveira Officer at Arms

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    Nothing changed operationally. Only the US and EURO BIOSes have an new "option" for increasing compatibility a little. Skipping the SEGA logo does solve problems for some games (but break others) so I had it as an option.

    Because skipping SEGA logo break a couple games and it doesn't add to compatibility, on Japanese BIOSes I did not add the skip logo code.

    An last thing I forgot to mention. On USA and EURO files I added a mild memory clear routine executed after the logo which wipes some vestiges of the logo execution. That fixes odd colored borders during videos on Tenbu MEGA-CD and the Japanese release of Time Gal. (these two work fine without needing to disable the logo)

    edit:woot 3003 lol
     
    Last edited: Oct 26, 2014
  4. RandQalan

    RandQalan Rapidly Rising Member

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    Thanks this helps some games on picodrive
     
  5. l_oliveira

    l_oliveira Officer at Arms

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    Rand these aren't for emulators they're for using on the real machine! lol

    But if it helps you out, more power to you. ;)
     
  6. RandQalan

    RandQalan Rapidly Rising Member

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    Yes I know they are for real deal but funny they work well with picodrive psp so far that is :)

    For CD game must have bios for it to work and the real bios has problems with some games but so far your region free works good
     
    Last edited: Oct 26, 2014
  7. l_oliveira

    l_oliveira Officer at Arms

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    I know they work ! XD

    I tested them thoroughly before uploading. I would had them uploaded a lot earlier but then I found a bug, so I had to rework all of them. LOL
     
    RandQalan likes this.
  8. Shane McRetro

    Shane McRetro Blast Processed Since 199X

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    Great timing! Any chance I could get you to patch up the LaserActive one for region free at least? (if you haven't already for me in the past!)
    I'll be taking that MCD1 though to plonk in my prize unit.

    Edit: ... and ummm duhhh thanks! How'd I forget that! :)
     
    Last edited: Oct 27, 2014
  9. PrOfUnD Darkness

    PrOfUnD Darkness Familiar Face

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  10. l_oliveira

    l_oliveira Officer at Arms

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    I have tried, but I don't have an laseractive unit. It requires a patch for the LD DISC SUB CPU BIOS, which I can't understand very well how it checks the disc region nor I have any means of testing such a BIOS.

    Unfortunately the Laseractive uses the LD BIOS to do the first regional detection.
     
  11. Ragnarok

    Ragnarok Member

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    I'm Gonna have to load these on my Everdrive and test tomorrow. Just as well I haven't done any mega cd Modding yet.
     
  12. l_oliveira

    l_oliveira Officer at Arms

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    While they should work in the everdrive just fine, the point of these is run as the main bios without anything attached to the MD. So IMHO they're best fitted inside of the unit as a replacement boot ROM.
     
  13. APE

    APE Site Supporter 2015

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    I have two Laseractive units (one won't display composite video signals and sprites on my sole Mega-LD title are corrupted and in B&W, the other has a tray issue I need to fix) so I could test region free code but I'll need to get a Japanese Mega-LD title first.

    And I'd be happy to sell my malfunctioning unit for a low price in the hopes it can be useful and repaired.


    Also, if anyone would like me to burn off an EPROM of these I'm happy to do so. Should have a number of compatible spares.
     
    Last edited: Oct 27, 2014
  14. l_oliveira

    l_oliveira Officer at Arms

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    MEGA-LDs have no region lock that I know of.

    The sub CPU LD BIOS check the disc and if it's a CD (of matching region) the (main) BIOS unloads the SUB CPU LD BIOS and reloads the CD BIOS before booting the game.
     
  15. Shane McRetro

    Shane McRetro Blast Processed Since 199X

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    Ah right! So it's stuck with native games then or those without region protection. Thanks for the explanation and keep up the good work!
     
  16. Shane McRetro

    Shane McRetro Blast Processed Since 199X

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    Nooooooo, no no no no! That's the last thing I'd need - more things to prod! :p
    I've got someone dropping by to pickup the unit tomorrow, so I hope it is of use to them - they already had PAC-S1 and PAC-N1 but the unit itself died somehow, I should ask how actually...
     
  17. dutchconsolefreak

    dutchconsolefreak Peppy Member

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    Quick question:

    jp_wmg_920206_regfree.bin = Wondermega M1
    WONDERMEGA-G303_regfree.BIN = Wondermega M2
     
  18. l_oliveira

    l_oliveira Officer at Arms

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    Yep. M1 is a tray type unit. Unsurprisingly the M1 bios work fine on tray model SEGA/MEGA-CD units.

    The M2 BIOS would *maybe* work on SEGA/MEGA-CD2 units but I don't own any working one I could use to test.

    Edit: And nope, it was not me who named these files. lol
     
    Last edited: Nov 29, 2014
  19. Shane McRetro

    Shane McRetro Blast Processed Since 199X

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    Perfect! Just tested out the PAL "eu_mcd1_921027_regfree.bin" and it worked a charm in my 1.00 Mega-CD Model 1.
    NTSC, Japan, Europe - all great!

    Back to Batman Returns I go! Love that soundtrack.
    Thanks again for the great modwork l_oliveira!
     
  20. l_oliveira

    l_oliveira Officer at Arms

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    Just confirmed Wonder Mega M2 (G303) and X'Eye BIOSes on the region free 2.00 set work perfectly.

    Still, these only work properly on these machines. (WonderMega M2 and X'Eye are the same hardware)

    Also, I do not support using any of these region free BIOSes with the Everdrive(s).
    (that may get rectified in the future with changes being made to the Everdrive design but then, that's beyond anything I can do to help.)
     

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