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Thread: Dumping Bioses

  1. #31
    Road Rasher l_oliveira's Avatar
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    Well, I gotta comment that the CD1 has a small heatsink but the IC it uses for 5V conversion is slightly better in efficiency department than the plain 7805 IC.

    I would avoid using a prototype console as wearing it down you are reducing it's value. It's a historical item.
    I'd like to share some wisdom:
    Quote Originally Posted by TmEE
    I'm too lazy to be unstoppable.
    you can have shame, as long as you don't feel it

  2. #32
    Nameless One
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    Yeah, I wasn't planning on using it very often. Bios dumped now;

    http://assemblergames.com/l/threads/...er-1-11.64045/

  3. #33
    Master of Shinobi
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    If you still have it disassembled, could you please make some screenshots of various parts of the board, and the ICs? Especially the bios chip, I can't quite read the markings on it.

    edit: does the Megadrive have a serial sticker on its back?

  4. #34
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    Yeah, I'll document the various ICs when I get the bios chip back. The Mega Drive doesn't have any stickers on it.

  5. #35
    Master of Shinobi
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    Sounds great!

    And thanks for dumping and sharing the bios chip!

  6. #36
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    Quote Originally Posted by Mask of Destiny View Post
    My "Transfer Suite" works fine with my region converter tool. Be warned that there is a small flaw in that there are a couple of bytes from the BIOS that are overridden by a register value when read from the normal address. I should really update it to read from a mirror instead. This doesn't really matter for actually using the dumped BIOS, but if won't technically be bit perfect to what's in the ROM.

    For what it's worth, it should be pretty straightforward to write a dumping tool for a more recent flash cart, especially one like the Mega Everdrive that has a USB serial connection.
    Could you be more specific on which bytes need to be read from somewhere else?
    I wrote a dumper
    http://www.sega-16.com/forum/showthr...CD-bios-dumper
    and my dumps are either undumped versions or suffer for the problem you mention.
    From what you say I believe it's the latter, so I'd like to fix that.

  7. #37
    Hedgehog-in-Training Hedgehog-in-TrainingNameless One Pha's Avatar
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    Quote Originally Posted by Mask of Destiny View Post
    My "Transfer Suite" works fine with my region converter tool. Be warned that there is a small flaw in that there are a couple of bytes from the BIOS that are overridden by a register value when read from the normal address. I should really update it to read from a mirror instead. This doesn't really matter for actually using the dumped BIOS, but if won't technically be bit perfect to what's in the ROM.

    For what it's worth, it should be pretty straightforward to write a dumping tool for a more recent flash cart, especially one like the Mega Everdrive that has a USB serial connection.
    You plan to update your "suite" what good news, on this subject an option of the choice of the communication port (controller port 1 or 2 and "ext" of the firsts md...) would be welcome !
    An innovative game on md/gs ? I vote for.

  8. #38
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    Quote Originally Posted by BKK View Post
    Yeah, I wasn't planning on using it very often. Bios dumped now;

    http://assemblergames.com/l/threads/...er-1-11.64045/
    anyone that have this file can repost now that assembler is dead?

    edit: nvm, its here
    https://segaretro.org/Sega_Mega-CD/Boot_ROM

    It should be noted however, that this is not in any way a prototype model 2 bios. 1.11 is just the last version of the original model 1 japan bios. and its a really rare version. I've only seen it in an actual japan model 1 once in my life. I believe it was never on factory units, and only found on units that were sent to sega for repair.

    https://segaretro.org/images/2/2e/Se..._Bulletins.pdf
    lists the header of the last japan model 1 cd bios, the checksum given $f074, is the same as this. So its definitely not a prototype model 2 BIOS.
    Last edited by deadscreem; 01-08-2020 at 03:49 AM.

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