Hacking Emulation Gaming Oldies Mega Man ROM hexes

[MeowthBlep]

Hello again.
I extracted Mega Man 1-6 from Arcade1UP’s Mega Man HDMI TV console firmware update, however, the ROMs do not seem to be the originals, as the do not work with RetroAchievements or scan into RetroArch. Could you guys provide me with a picture of the hex codes so I can edit them to the originals?

 

[MeowthBlep]

Bmup

 

[cearp]

Could you guys provide me with a picture of the hex codes so I can edit them to the originals?

That's not how it works. A bit like going to the bank and telling them to update your balance to $1,000,000 - you need to actually have the right money / data.
Once you have the expected amount of money / correct data, your bank balance (file checksum) will be updated when you check.

 

[MeowthBlep]

That's not how it works. A bit like going to the bank and telling them to update your balance to $1,000,000 - you need to actually have correct money / data, and your bank balance (file checksum) will be updated when you check.

Could you at least tell me the differences

 

[Robert Newbie]

If I'm understanding this right, ARCADE1up released this pack here:

The problem is that the ROM's included with this bundle were modified. In cases like these, the devs usually add screens and logos to the start of each game, update copyright information, and even change some game content (Typo corrections, bugfixes, etc.). All of that culminates in an altered file, and files that deviate from the original will have a different checksum.

Some of the changes are easily visible to the end user, like copyright info, but more subtle alterations aren't. Either way, it means that the ROM's aren't compatible with any programs or tools that rely on specific checksum values. I guess you could compare the original and the ARCADE1up versions in a hex editor, but I wouldn't recommend doing so unless you think there's something interesting to find. Is there a reason you want to play these specific versions of the games?

 

[MeowthBlep]

Snip

I want to edit the roms back to the original so that I can use retroachievements

 

[Robert Newbie]

I want to edit the roms back to the original so that I can use retroachievements

Aaah, wouldn't that just edit the ROM's back to their originals? Meaning, you wouldn't get any of the benefits of whatever changes were made to the games in the ARCADE1up release because they'd be edited out in order to match the originals byte-for-byte. None of the ARCADE1up-exclusive code would survive because all of those changes would need to be reverted/removed to create a matching checksum.

Essentailly, you'd be reconstructing what is already readily available.

 

[Nakamichi]

I want to edit the roms back to the original so that I can use retroachievements

its simple, get the original mega man roms, create an IPS patch by comparing them to the modified arcade1up roms and then you have the patches to convert any arcade1up rom back to the original!

... and that would be just about the most futile thing anyone could ever do.

The changes will not be so minimal that someone could give you one single code-snippet here to change them to the originals anyway, so what you are requesting is, basically, that someone post the entire code of the mega man roms or check, in detail, for every single difference between the two and then tell you exactly where to apply those changes.

..... which would be the second most futile thing anyone could ever do.

 

[Robert Newbie]

its simple, get the original mega man roms, create an IPS patch by comparing them to the modified arcade1up roms and then you have the patches to convert any arcade1up rom back to the original!

Oooh, I never even thought about the IPS route! That'd speed up the process ten-fold. My head was stuck in hex editing mode, but that would have been painstaking.

I've never used RetroAchievements, but if it wants a specific ROM, you cannot substitute a single bit because the checksum would end up being incorrect and incompatible. I didn't know this item existed until today, but I wouldn't expect major changes to the ROM's. Just the standard logo additions and copyright info changes.

It makes me wonder if the "FAILD" typo is still in Mega Man 6:

 

[MeowthBlep]

The changes will not be so minimal that someone could give you one single code-snippet here to change them to the originals anyway

That’s what I want

 

[Robert Newbie]

Rereading your original post, I see that even emulators can't run the extracted files. I'd be surprised if they weren't ROM's running on an emulator, since that's the most cost-effective choice for standalone mini-consoles like these, but I wonder if they're in a unique format. That may further complicate your goals. What are the file extensions for the extracted games?

 

[MeowthBlep]

What are the file extensions for the extracted games?

.nes
They do work on emulator, they just don’t scan into the launcher

 

[hippy dave]

Download the original ROMs.

If you don't want to, because you don't own them and that would be piracy, then be aware that the only way someone could give you the changes you wanted was if they had downloaded the original ROMs, which would be piracy, and also if (most likely) they didn't also happen to own the modified ROMs that you have, they would need to download them, which would be piracy.

You're not going to achieve any moral win if you avoid piracy yourself by convincing someone else to do more piracy. Just download the original ROMs.

 

[Robert Newbie]

.nes
They do work on emulator, they just don’t scan into the launcher

Interesting. I guess it was RetroArch that had issues with the files. At this point, you may want to consider using something like HexEd.it and comparing each file bit-by-bit with their originals. The community does appreciate deep dives like these, so I recommend documenting your findings in detail. Since your goal is very specific, it'd be difficult to recruit someone to do this particular task for you.

 

[MeowthBlep]

Interesting. I guess it was RetroArch that had issues with the files. At this point, you may want to consider using something like HexEd.it and comparing each file bit-by-bit with their originals. The community does appreciate deep dives like these, so I recommend documenting your findings in detail. Since your goal is very specific, it'd be difficult to recruit someone to do this particular task for you.

…

Download the original ROMs.

If you don't want to, because you don't own them and that would be piracy, then be aware that the only way someone could give you the changes you wanted was if they had downloaded the original ROMs, which would be piracy, and also if (most likely) they didn't also happen to own the modified ROMs that you have, they would need to download them, which would be piracy.

You're not going to achieve any moral win if you avoid piracy yourself by convincing someone else to do more piracy. Just download the original ROMs.

Ok.
My Wii U does have MM1-3 on it, but it’s getting fixed rn, so when it is fixed I’ll give y’all the differences