Bios mod and mod chip together....Would this cause problems?

Discussion in 'Sega Dreamcast Development and Research' started by segadreamcaster, May 4, 2012.

  1. segadreamcaster

    segadreamcaster Member

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    Hi all,

    I installed a 4 wire mod chip a few years ago and have just installed the bios mod...now I have the chip still inside the dreamcast but have disconnected it. Now this is more curiosity than anything else, but does anybody know if it would cause issues having the 4 wire mod chip fully installed as well?

    I imagine it might interfere with the unlocked bios but would function as normal when the original bios was selected?

    Any thoughts?
     
    Last edited: May 4, 2012
  2. segadreamcaster

    segadreamcaster Member

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    Ok,

    I just thought I would post to say I gave this a try for anybody else who might be interested in knowing.

    It seems to work intermittently, the original bios always seems to work ok with it and region free as well, but the new bios is more sketchy....sometimes it just won't boot up from it with the mod chip installed....other timesit seems to work fine for an extended period of time.

    I get the feeling this might produce mixed results.

    Cheers
     
  3. APE

    APE Master Baiter

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    Why would you need a modchip installed in conjunction with the region free BIOS?
     
  4. Lum

    Lum Site Soldier

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    Dreamcast modchips are woefully underrated.
     
  5. segadreamcaster

    segadreamcaster Member

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    The only reason I was really interested in having the modchip installed along with the bios mod, was to allow for dreamshell to be flashed on the new bios and keep a region free original bios as well and then be able to switch between the two easily.

    Sadly this does not seem to work reliably so I gave up on it
     
    Last edited: May 7, 2012
  6. Bad_Ad84

    Bad_Ad84 Keyboard Error: Press F1 to Continue

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    Just install 2 flashable chips. Put region free on one and dreamshell on the other.

    I have done this a few times
     
  7. Calpis

    Calpis Champion of the Forum

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    Considering that the modchip OVERPOWERS a bit or few the BIOS outputs, it will continue to do this to the "BIOS modded" BIOS (which?). If you are running a hacked BIOS on flashROM then it's not smart to keep the modchip because not only is it redundant, but the flashROM might not be as overpowerable as the maskROM. The modchip's bus contention is not a safe practice so it shouldn't be used at all, and also CPLD are power hungry so the point where power is tapped may be a burden to the surrounding parts.
     
  8. segadreamcaster

    segadreamcaster Member

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    Yeah, I think the mod chip was taxing the power a little too much as it seemed to still be a problem when all other links werer removed.

    As for using a second flashable chip...yes, that is an option worth considering....I will probably leave it for now to see how often I use dreamshell to see if it will be worth it...or just use the disc / flash when needed.
     

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