Dreamcast Bios Options - What's out there?

[segadreamcaster]

Hi All,

I have just done a bios chip installation and have been able to install the link83 bios with the developers box intro so that it is region free using Dreamshell 4.0 RC1.

I seem to be in the minority but I am not overly keen on the developers intro and would ideally like to be able to have a standard retail bios which is region free. Is this available anywhere?

Any other different bios's available other than whats on the dreamshell disc?

Thanks for any help guys :)

[l_oliveira]

load link93 and matching original bios on winhex (Any other kind of tool capable of comparing two files will work for you), compare files.

There's a offset with only two changed bytes, change that on the original bios.

Save it, write on your DC. Enjoy.

[segadreamcaster]

load link93 and matching original bios on winhex (Any other kind of tool capable of comparing two files will work for you), compare files.

There's a offset with only two changed bytes, change that on the original bios.

Save it, write on your DC. Enjoy.

Hi,

Thank you very much for the reply.

Is there any chance you could elaborate a little on that? I have a hex editor already, but have just installed winhex to try it out.

I have extracted the Link83_bios_1.0.bios file from the dreamshell disc but am now a little stuck?

Also, you say "save it and write to DC" but how is this done...remember, I have only used the dreamshell disc for flashing so far?

Thanks again for your help

[l_oliveira]

Well after you have your file, you will need to make a new dreamshell disc with the new bios file in it.

[segadreamcaster]

Ok, feeling a little useless here.

Where do I find a matching original bios? I am looking at the various ones on the dreamshell disc but there are various options.....have tried comparing them using tools, file options, compare but not sure what to do from there?

I assumed I would need to burn a new dreamshell disc, hopefully I should be able to figure that out once I have the desired file.

Appologies, I am pretty new to this. Is there a guide for this process anywhere online I can look at do you know?

Thanks again

[l_oliveira]

It's simpler than what you're thinking.

The two BIOS will be the exact skeleton, it's just that LINK93 one had sound and video resources for boot up changed.

One of the four kinds of retail Dreamcast bios match it. So if you compare the files what you will see is what LIN93 changed on his file. You ignore all the big changes and take only a change which has two consecutive bytes. I can't tell you the exact change because I can't remember exactly what it was but I am sure that was discussed on this board and also at the NFG (gamesx) forum.

I gave LINK93 the list of bytes to patch, taken from my own Dreamcast but honestly I don't remember the exact patch. Maybe if you search the board you can skip the file compare thing. :)

[segadreamcaster]

Ok, I will give it a try tomorrow, unfortunately I have to leave it now....will post back to let you know how I get on...wish me luck :)

[segadreamcaster]

I think I am gonna have to give this one up :(

I continued to try comparing to figure out what needed changing, but still din't get very far, so eventually did a bit of searching and found what should be a region free retail bios. I have since attempted to edit a dreamshell cdi using ultraISO, PowerISO and MagicISO but all I seem to get are coasters. I know I have used these programs before to edits CDI, ISO and nrg files files for the DC but I cannot remember what I did differently.

Seems I am gonna have to give up on this one...perhaps I will be able to use my SD adapter (when it arrives) to load the new bios?

Thanks for your help

[segadreamcaster]

Ok, finally got it sorted :) Managed to get the bios file edited and then added to a working edited copy of Dreamshell...yah...now I have the option :)

Thank you very much l_oliveira, your help is very much appreciated :)

Now the next question is, whats the difference between the retail bios options? Is one any better than the other?