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Is there a Dreamcast Region-Free BIOS?

Started by keropi, June 07, 2010, 06:26:21 pm

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keropi

Hiya!!

I read in some post here about hex-editing a DC bios to make it region free... I searched and found no such info  ??? ... I already flashed my PAL DC to NITSC, but region-free would be great since all my originals would just work...
Anyone has any info on that?
Thanks!  :)

Endymion

There isn't one, but if you could get a mod chip to use then it would not really matter.

keropi

ah, I understood you could flash one  ::) I was happy there for a moment  :D
thanks!

l_oliveira

Quote from: Endymion on June 07, 2010, 06:50:14 pm
There isn't one, but if you could get a mod chip to use then it would not really matter.


Wrong.
There's a Region free bios and there's another bios with has both region free and Katana devkit target box boot screen:

Dreamcast Boot1

The only caveat is that the onboard ROM chip has to be replaced with a FLASH chip with the bios image flashed in it. As Endymion mentioned, the original chip is an MASK ROM which is not re-programmable.

Endymion

Quote from: l_oliveira on June 07, 2010, 11:17:17 pm
Quote from: Endymion on June 07, 2010, 06:50:14 pm
There isn't one, but if you could get a mod chip to use then it would not really matter.


Wrong.
There's a Region free bios and there's another bios with has both region free and Katana devkit target box boot screen:


Apologies. When I was keeping up, the Russians had given up on even trying. Is the Katana region free or does it even boot retails?

QuoteThe only caveat is that the onboard ROM chip has to be replaced with a FLASH chip with the bios image flashed in it. As Endymion mentioned, the original chip is an MASK ROM which is not re-programmable.


Well this would probably be why I'd not seen anything on it. I think that makes the current flasher along with a mod chip (if you can still get one) the more reasonable solution.

hellbelly

I can remember seeing a thread in here with a lot of input from Link83 - http://nfggames.com/forum2/index.php?topic=3334.0

Link83, did you get any further??

Pete

l_oliveira

The video was made from a real dreamcast running his hacked bios. This is a finished project.

It's a RETAIL ROM with sound and graphical assets edited. So it will behave like a retail Dreamcast.
It's not a Katana bios so it does read both GD-ROM and MIL-CD.

TJ_Kat

i know i read something around here about a program that allows you to change the region settings on any dreamcast without any hex editing or anything like that. i don't think it could make it region free, but you could switch it whenever you wanted. for the life of me, i can't find the thread anymore, nor can i find a like to the site that had the program. i'm really kicking myself right now for not having downloaded it when i had the chance. i'll keep looking.

l_oliveira

You can't switch "whenever you wanted" because the change requires to de-protect the secure part of the flash (permanent settings) and run a disc. 

The problem lies on the fact that you're required to connect 12v to the reset pin of the flash chip to override the write protection and that configuration will
cause damage to the flash chip in long term.

With a region free BIOS you can for example, set the swirl as BLUE to match a PAL system casing and controllers and still have it to output NTSC video.
And the KATANA target box boot animation is sexy enough to be interesting to have. :)

tertiumsquid

Quote from: l_oliveira on June 11, 2010, 07:55:23 am
You can't switch "whenever you wanted" because the change requires to de-protect the secure part of the flash (permanent settings) and run a disc. 


Does this mean that we can flash this region free bios to the original bios chip in the DC, so long as we connect 12v to reset once to unprotect it?  Or do we still have to replace the chip with a new one?  Any links available?

l_oliveira

Quote from: tertiumsquid on July 18, 2010, 04:14:45 pm
Quote from: l_oliveira on June 11, 2010, 07:55:23 am
You can't switch "whenever you wanted" because the change requires to de-protect the secure part of the flash (permanent settings) and run a disc. 


Does this mean that we can flash this region free bios to the original bios chip in the DC, so long as we connect 12v to reset once to unprotect it?  Or do we still have to replace the chip with a new one?  Any links available?


No, hooking the 12V wire is meant to unlock the (existing 128KB) flash memory chip so you can flash the protected section to change the region and video settings.
The BIOS/bootrom is an SEGA MASK ROM chip (cannot be re-programmed) and using an custom BIOS require replacing the SEGA MASK ROM chip with an 2 megabyte FLASH memory.

tertiumsquid

Quote from: l_oliveira on July 19, 2010, 02:07:44 am
No, hooking the 12V wire is meant to unlock the (existing 128KB) flash memory chip so you can flash the protected section to change the region and video settings.
The BIOS/bootrom is an SEGA MASK ROM chip (cannot be re-programmed) and using an custom BIOS require replacing the SEGA MASK ROM chip with an 2 megabyte FLASH memory.


Ok cool, that clarifies it.

TJ_Kat

*bump*

i stumbled across the link i had been looking for (http://www.lyris-lite.net/fu_archives/000601.html)

so, doing this, the 12V will damage the flash chip in the long run, but couldn't you just install a switch to turn the 12V off after the changes have been made? it does say it's supposed to be permanent.

l_oliveira

Quote from: TJ_Kat on October 21, 2010, 02:03:33 am
*bump*

i stumbled across the link i had been looking for (http://www.lyris-lite.net/fu_archives/000601.html)

so, doing this, the 12V will damage the flash chip in the long run, but couldn't you just install a switch to turn the 12V off after the changes have been made? it does say it's supposed to be permanent.


The 12V should be applied only on programming time so yes, that would be the best thing to do.

Jeroi

From where I can download the region free bios, if I would flassh 2mbit chip and direct replacement for dreamcast?

l_oliveira

Quote from: Jeroi on February 18, 2011, 06:04:22 am
From where I can download the region free bios, if I would flassh 2mbit chip and direct replacement for dreamcast?


It's copyrighted code so I can't simply link here.  It doesn't mean I don't have it. You know what I mean. ;)