Beta bootstrap + reset: Mission complete

I feel like some people like to claim that it is impossible when they fail to overcome problems. Fortunately, their vision has a limited influence. If I listened to all the negative comments about my projects, I would probably end up being like their authors, spreading my frustration over the Internet.

Anyway, that is not the point I want to talk about. Today, I am happy to report my progress. Let’s start with the bad news. In its current state, my next bios version cannot boot cheat discs like Action Replay/Gameshark/Code breaker and GDMenu. I know why and there are solutions to this. The good point is even though some people state that it is not possible, the beta-bootstrap I slightly modified works flawlessly with MIL-CD/backup, including the system reset. I can even add that I knew it would pass the holly protection before testing it on the real hardware. Pretty cool isn’t it? But to be honest, my moves are limited but I hope that in a near future I will be more free.

In short, I could release my bios right now, and release the “patched” cheat disc later. But I am not sure yet that this would be the best solution to introduce the custom cheat-disc for my bios, specially as there is a chance that I will overcome this issue. Booting custom bios is already a difficult task for users and I don’t want to bother them with a “special version” of games/applications. Anyway, whatever solution I come up with, the compatibility is not going to be impacted.

Stay tuned!

9 replies on “Beta bootstrap + reset: Mission complete”

Congratulation 🙂 Cant wait to test it. You are the master DC bios 😉 I will try to do another Paypal too ASAP.

Also now has you maybe see, many people patch games to get 16/9 on them TV. Do you think it’s possible to put the bios in 16/9? If yes that will make the game play in 16/9? If all is yes, will be great to got the option in the bios’s settings to select 4/3 or 16/9. haha But I guess it’s a dream.

Hi Thibaut,

Thank you for yout support!

So yes the bios can be put in 16/9 format but the modification only means the bios menu itself. Right now the version v1.032 is “feature complete” so I am not goung to add anything (otherwise I would never release anything!). More other, the in-bios menu is pretty full and I have to investigate further to integrate settîgs “pages”.
To support the 16/9 format in game, I have already started something, based on the codebreaker/action replay code list some smart guys have been working on: I don’t like to re-invent to well 😉

Another great update report!

I have a really silly question – is there a way to provide a ROTATED boot setup? I have dedicated one of my Dreamcasts to run on a Vertical screen setup – it’d be so nice to have the system boot vertical as well!

Hi! I really appreciate your work

I wanted to let you know that I found 2 addreses responsible of the aspect ratio using cheat engine, on the Dreamcast Bios, and I managed to make both the boot animation and Bios menu Widescreen.

The addreses/values once changed should be these.

2C071558 (02071558 on real hardware)

2C202B84 (02202B84 on real hardware)

It would be nice if you could implement it on your custom bios. the addresses are the same for most of the Dreamcast bios.

Some comparison taken using demul ( wich does not allow for widescreen hacks)



Any updates on this? I’m really interested in doing a bios mod after you release this. Will it have the option for a non-dev PAL blue swirl boot logo?

It’ll also be amazing to boot mil-cd without rebooting


So I am about to release it. I added some new features in the last minute that require testing. My dreamcast bios mod is broken and i don’t have the right equipement to fix it. If you want you can send me an email and you can help me doing the beta testing.

Anyway, you will have the choice between the normal or the Devkit bootanim, as always. Regarding the direct boot, it works correctly only with disc drive hardware emulator like gdemu (usb gdrom seems to have spme issue with this thought)

Thanks for your support

Wonderful work good sir! I have just successfully modded my Dreamcast with a region free bios. Your work is much appreciated 🙂

Leave a Reply