NAOMI PSEUDO-DEVELOP BIOS

[mathieulh]

https://mega.nz/file/ptlnXJDT#D6O20DYouR6e7E2LM1WIyzMQHKHq96bV8ECuRqyyEcg

These BIOSes enable the development features back, 0x1FFD50
has been changed back to NAOMI DEVELOP and the first 0x400 have been overwritten with the development naomi hat/bootstrap. (yes, actual development BIOSes such as the dumped 1.10 use it)


Only use these if you know what you are doing, some games will likely NOT work with those.

-Mathieulh

I am aware this wasn't especially hard to pull off, I just thought it may be useful to people who want to experiment with development features but are unaware of what changes to make on BIOSes or how they are constructed to enable those features back.


Credits go to the followings:

@MetalliC for documenting how editing the NAOMI BIOS string at 0x1FFD50 enable development features. (see here: git.redump.net/mame/plain/src/mame/drivers/naomi.cpp)
@mathieulh for modifying the existing bioses (seriously, anyone other than myself could have done that part with 5 minutes of research after reading the provided documentation)

 

[MetalliC]

yes, actual development BIOSes such as the dumped 1.10 use it

no, they are not.
also that 1.10 dump is not development BIOS

These BIOSes enable the development features back, 0x1FFD50

no, these are not enable development features back, they should be enabled in other place and I didn't told you where, so these are not enabled

Only use these if you know what you are doing, some games will likely NOT work with those.

Only do such mods if you really know what you are doing

 

[mathieulh]

yes, actual development BIOSes such as the dumped 1.10 use it

no, they are not.also that 1.10 dump is not development BIOS

These BIOSes enable the development features back, 0x1FFD50

no, these are not enable development features back, they should be enabled in other place and I didn't told you where, so these are not enabled

Only use these if you know what you are doing, some games will likely NOT work with those.

Only do such mods if you really know what you are doing

If 1.10 is "not a development bios" why it, and others the are also using the beta hat, are referenced in the mame database as "good dumps" ? Or even here: https://git.redump.net/mame/plain/src/mame/drivers/naomi.cpp

Finally,
A lot of features are actually enabled once you change the string at 0x1FFD50, feel free to enlighten us as to which aren't.

 

[MetalliC]

If 1.10 is "not a development bios" why it, and others the are also using the beta hat, are referenced in the mame database as good dumps ?

these 2 dumps we have is kind of "hardware testers", for mother boards and ROM boards testing, reprogramming, etc servicing purposes, it seems made mainly for repair workshops.
they are good dumps, but not BIOSes for NAOMI dev. boxes, at the moment we have no NAOMI dev.box BIOS dumps at all.

feel free to enlighten us as to which aren't.

why ? so you'll do another c00l release based on my work ?

 

[mathieulh]

feel free to enlighten us as to which aren't.

why ? so you'll do another c00l release based on my work ?

Right, so now I am stealing your work. Feel entitled much?

 

[djsheep]

@MetalliC, the whole song and dance you put on when almost anyone releases anything related to Naomi is getting a bit tired...

If you want props, perhaps actually release something or do something? If you’re going about being critical of others work, how about releasing the actual “c00l” version.

You’ve blamed a language barrier as being the cause of all the drama you bring, but I have my suspicions it’s more related to a superiority complex.

K-Rad.

 

[MetalliC]

the whole song and dance you put on when almost anyone releases anything related to Naomi is getting a bit tired...

If you want props, perhaps actually release something or do something? If you’re going about being critical of others work, how about releasing the actual “c00l” version.

or do something ? I did all the hard research work, and explained how this dev detection works few days ago Naomi multi BIOS (fixed with proper bootstrap)

and voila! - few days later we got NEW SUPER RELEASE!, and of course with no any credits for person(s) who did actual work.

you know how it smells...

 

[mathieulh]

the whole song and dance you put on when almost anyone releases anything related to Naomi is getting a bit tired...

If you want props, perhaps actually release something or do something? If you’re going about being critical of others work, how about releasing the actual “c00l” version.

or do something ? I did all the hard research work, and explained how this dev detection works few days ago Naomi multi BIOS (fixed with proper bootstrap)
and voila! - few days later we got NEW SUPER RELEASE!, and of course with no any credits for person(s) who did actual work.

you know how it smells...

I don't like drama, so I am going to answer this once because this is seriously getting tiresome and to be honest, I feel like your behavior is borderline toxic.


- About the multibios "research": Seriously it's a 2 bytes change enabling sega functions ANYONE can spot withing minutes using IDA. Using the beta hat/bootstrap using trial and error isn't rocket science either (sega wrote that, you didn't; it's not exactly hard to find either, considering it's used in all "development" bioses and in the HOTD2 prototype bios, putting 2 and 2 together isn't hard.) Don't act as if you suddenly were a messiah and that only you could have figured out all that stuff.

If you didn't bother checking the actual holly hash before trying to use the beta hat to bypass it, well that's not my fault now is it? There aren't millions of possible patches to re-enable the sega code for region switching, did I say I did not reuse your patches (I am assuming p1pkin is you?) I did not; in fact I openly stated I applied the original bootstrap on top of the already existing multi bioses.

The patches themselves are fairly easy to find nonetheless, in fact, I did not want to post these before they were being tested on real hardware, but I here are other (older) versions of the BIOS I made with the exact same multi bios patches (which I had posted on the openjvs discord for testing purposes).

https://mega.nz/file/8011wRYL#XvAMRHD42EDJbghhGAEM1B5mQfErOPxd8qXZNtPP6Zo

As you can see for yourself, the patches are at their proper locations.

I did not post all this for credits or to compete or anything, if I was in this for any kind of notoriety, I have done much greater achievements than any of this (I daresay easy) stuff, I don't need to be "stealing" whatever you've done, if you feel that way, that's your prerogative, I don't care.

- About the "development" bios:

I didn't own an arcade system less than a month back, so obviously others, such as MetalliC, will know more than me about some (probably most), related arcade development stuff, since they have been been messing with arcade boards for years. How am I to remotely guess that a development bios marked as such and as a good dump isn't "from a development box", and how does that make it not behave like a proper development bios? How can you or anyone else even tell as "no dumps exist". I work with what I have that's dumps, and open documentation.

Finally, I am not saying you aren't helpful, the info about the time bomb flag for instance was genuinely helpful, I in fact credited you for it! I don't shy on giving credits where it's due.

https://github.com/mathieulh/SEGA_DIMM_CD-R

Finally the "DEVELOP" part in the NAOMI BIOS is actually openly documented here https://git.redump.net/mame/plain/src/mame/drivers/naomi.cpp

Can we now please stop the drama? This is pointless, I am not competing here, if you feel so insecure as to believe I am somehow stealing your work/credits/whatever, that's up to you.

 

[AMS]

I love how drama gets me to interesting stuff I’ve never seen before Keep up the good works lads

 

[MetalliC]

- About the multibios "research": Seriously it's a 2 bytes change enabling sega functions ANYONE can spot withing minutes using IDA. Using the beta hat/bootstrap using trial and error isn't rocket science either (sega wrote that, you didn't; it's not exactly hard to find either

it isn't hard to find something if you know what, but at that moment it was not known BIOSes have hidden region-switching feature, so discovering it had involved a lot of analysis, and actually was side effect of whole BIOS research&disassembly, which took quite much of time in general.

If you didn't bother checking the actual holly hash before trying to use the beta hat to bypass it, well that's not my fault now is it?

this is another story. actually I've checked patched BIOSes, but using Dreamcast, and that was wrong move - as it turned out now, neither of retail NAOMI BIOSes pass the check using Dreamcast. so, I've got negative results, even if patched bioses works fine on NAOMI as we see now

Finally the "DEVELOP" part in the NAOMI BIOS is actually openly documented here

well, it was documented there by me too (same as significant part of other NAOMI docs there), but this not explaining why not to put few credits/thanks words here...

I didn't own an arcade system less than a month back, so obviously others, such as MetalliC, will know more than me about some (probably most), related arcade development stuff, since they have been been messing with arcade boards for years.

as was said earlier - I don't own any arcades, never had, and not any involved in arcade or related business.
but yes, there was quite much of time spent for this hardware research, mainly during development of Demul emulator.

 

[mathieulh]

- About the multibios "research": Seriously it's a 2 bytes change enabling sega functions ANYONE can spot withing minutes using IDA. Using the beta hat/bootstrap using trial and error isn't rocket science either (sega wrote that, you didn't; it's not exactly hard to find either

it isn't hard to find something if you know what, but at that moment it was not known BIOSes have hidden region-switching feature, so discovering it had involved a lot of analysis, and actually was side effect of whole BIOS research&disassembly, which took quite much of time in general.

If you didn't bother checking the actual holly hash before trying to use the beta hat to bypass it, well that's not my fault now is it?

this is another story. actually I've checked patched BIOSes, but using Dreamcast, and that was wrong move - as it turned out now, neither of retail NAOMI BIOSes pass the check using Dreamcast. so, I've got negative results, even if patched bioses works fine on NAOMI as we see now

Finally the "DEVELOP" part in the NAOMI BIOS is actually openly documented here

well, it was documented there by me too (same as significant part of other NAOMI docs there), but this not explaining why not to put few credits/thanks words here...

I didn't own an arcade system less than a month back, so obviously others, such as MetalliC, will know more than me about some (probably most), related arcade development stuff, since they have been been messing with arcade boards for years.

as was said earlier - I don't own any arcades, never had, and not any involved in arcade or related business.but yes, there was quite much of time spent for this hardware research, mainly during development of Demul emulator.

I didn't know you were the one who added this in the documentation, I do not mind adding credits to you at all if that's the case, as I mentioned in the original post, making the DEVELOP bioses (my involvment in it that is) wasn't anything special, obviously I could do it because it was documented to begin with.

I am aware this wasn't especially hard to pull off, I just thought it may be useful to people who want to experiment with development features but are unaware of what changes to make on BIOSes or how they are constructed to enable those features back.

UPDATE: I added this to the original post as well as directly in the archive's readme:

Credits go to the followings:

@MetalliC for documenting how editing the NAOMI BIOS string at 0x1FFD50 enable development features. (see here: git.redump.net/mame/plain/src/mame/drivers/naomi.cpp)
@mathieulh for modifying the existing bioses (seriously, anyone other than myself could have done that part with 5 minutes of research after reading the provided documentation)

 

[stj]

can you post the source for Naoiso on your github page?

 

[idc]

can you post the source for Naoiso on your github page?

If the original author is fine with it, it will be shared in due course.

 

[mathieulh]

can you post the source for Naoiso on your github page?

It's just been added.

 

[idc]

It's just been added.

Excellent, now someone can use it to make a nice conversion tool.

I ask that people understand that this code stems from a leak. As such, it’s not finished ‘production-quality’ code, it’s a hack, with further hacks added in by Mathieulh to fix up a couple of things.

It already pulls the xxx.BIN boot file name from the source ISO. Might worth adding in the known keys as a table, cross-referencing against the xxx boot filename, to pre-populate the decryption key. If someone is brave enough, they could perhaps add in MAME CHD import functionality.

 

[stj]

we can add a patcher to make games region-free with the info MetalliC posted the other day

 

[mathieulh]

we can add a patcher to make games region-free with the info MetalliC posted the other day

If you want to make a game region free, just set the byte 0x428 (in the game binary) to 0xFF.

 

[stj]

i know, but i mean have the util do it.

 

[MetalliC]

with the info MetalliC posted the other day

have to admit, this was known like since decade ago, so I was not involved here

 

[stj]

maybe, but i didnt know till i saw your post.

your a prophet