The hacking of Sonic 3 problems

Stealth · Feb 21, 2006

Well, there are actually two problems. I just realized what it is you're editing in the example; You weren't clear in your text, but the label in your hex editor implies that you're talking about the Wily art you're trying to replace Eggman with. Eggman's sprites are one of the things that are duplicated in Sonic and Knuckles because they're needed when playing Sonic and Knuckles alone. Duplicate data like that is read from the Sonic and Knuckles ROM reguardless of whether you're playing a Sonic 3 or a Sonic and Knuckles level, which is another reason certain changes to Sonic 3 won't appear in Sonic 3 and Knuckles. You have to change their Sonic and Knuckles counterparts

As for the offset Sonic 3 data , I mentioned in my first response that Sonic and Knuckles has updated pointers for them. It's just a matter of basic math and repeating the search method from Sonic 3. The only unobvious thing is the more hardware-related matter of where the ROMs exist. Because Sonic and Knuckles is the main ROM, it exists at the beginning of normal ROM addressing space, so Sonic 3 has been re-mapped and no longer starts at $000000. The next best place for it to be is right at the end of Sonic and Knuckles, starting at $200000. In that sense, think of the absolute 32-bit pointers as relative pointers from ROM start. I'm hoping I can give you just enough for you to get a start and fill it in yourself, so that you actually understand

Guardian · Feb 21, 2006

Stealth said:

Well, there are actually two problems. I just realized what it is you're editing in the example; You weren't clear in your text, but the label in your hex editor implies that you're talking about the Wily art you're trying to replace Eggman with. Eggman's sprites are one of the things that are duplicated in Sonic and Knuckles because they're needed when playing Sonic and Knuckles alone. Duplicate data like that is read from the Sonic and Knuckles ROM reguardless of whether you're playing a Sonic 3 or a Sonic and Knuckles level, which is another reason certain changes to Sonic 3 won't appear in Sonic 3 and Knuckles. You have to change their Sonic and Knuckles counterparts

As for the offset Sonic 3 data , I mentioned in my first response that Sonic and Knuckles has updated pointers for them. It's just a matter of basic math and repeating the search method from Sonic 3. The only unobvious thing is the more hardware-related matter of where the ROMs exist. Because Sonic and Knuckles is the main ROM, it exists at the beginning of normal ROM addressing space, so Sonic 3 has been re-mapped and no longer starts at $000000. The next best place for it to be is right at the end of Sonic and Knuckles, starting at $200000. In that sense, think of the absolute 32-bit pointers as relative pointers from ROM start. I'm hoping I can give you just enough for you to get a start and fill it in yourself, so that you actually understand
Click to expand...

Indeed. That is the sprite I am replacing. Among other sprites as well. Sorry I wasn't too explainable from my last post. Changing the Sonic & Knuckles counterpart's is going to be a problem for me. Because I have absolutely no idea where Robotnik's sprites offset's are located in the "S&K" rom. You see, Sega Data Compressor doesn't list that game at all. Even if I do start at 00200000, I wouldnt know where to begin to search for it.

I know that in hex workshop, in a converted S3&K rom, S&K seems to located on top, ending at 00200000 and S3 on bottom, ending with 00400000. The problem now is to locate it. Finding that second pointer. I thought I saw some offset location's for S&K on this site somewhere. Perhap's I could use those and just paste my compressed art in that rom as well. Then it should work. However I don't know where they are on this site. IF they exist. Look's like I won't be able to hack into that game. 'Sigh'. Thank you for your help Stealth. I appreciate it.

Liliam · Feb 21, 2006

Well, I'm no ROM hacker, but my instinct tells me that if the art in the S&K ROM is an exact duplicate of the one in Sonic 3, a simple search would find you the art, provided that it is indeed the same as in the Sonic 3 ROM. Then you would just take the offset, add your art and change the pointer from the offset found through your previous search to the new art's address. This is just speculation, however.

Tweaker · Feb 21, 2006

Stealth said:

It seems like you didn't realize that the modified pointers in the Sonic 3 ROM don't affect the Sonic and Knuckles program. When Sonic 3 is shifted to the $200000-$400000 address space, all of the absolute references (32-bit address pointers) are invalid, because they're pointing to the original $000000-$200000 space, where Sonic and Knuckles is. This means that code with absolute jumps rather than branches can't be run, and lists of absolute pointers are meaningless. The entire program is run from the Sonic and Knuckles cartridge (with the exception of the level area events code for the original Sonic 3 levels, which use relative references), and any pointers to data that only exists in Sonic 3 have been re-listed to point to their new locations rather than where they'd be in Sonic 3 alone. In effect, you've only told Sonic 3 where to find your changes, not Sonic(3) and Knuckles
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I told him this for like an hour straight and he didn't get it. S3&K, while combined with S3, runs on S&K programming. as such, each pointer to S3 data will be seperate from the S3 pointers themselves. It's not hard to understand... Just change the S&K pointers and you're set.

Quickman · Feb 21, 2006

I'd just like to congratulate this guy for being a significant rarity - an intelligent newbie.

Guardian · Feb 21, 2006

Neo Chaotikal said:

Well, I'm no ROM hacker, but my instinct tells me that if the art in the S&K ROM is an exact duplicate of the one in Sonic 3, a simple search would find you the art, provided that it is indeed the same as in the Sonic 3 ROM. Then you would just take the offset, add your art and change the pointer from the offset found through your previous search to the new art's address. This is just speculation, however.
Click to expand...

Apparently not. I did search for address 18041E in S&K, pasted my art, sadly no. It still did not show up in the rom. That means that it's located at an entirely different offset. Thank's for the help though. Tweaker, I did change that pointer in S&K. It's not the correct offset.

Liliam · Feb 21, 2006

Did I tell you to paste your art in the same location as on the Sonic 3 ROM? I don't think so. I told you to search for the content of the art found in Sonic 3 on the S&K ROM. If the art is the same, you should get a match. Then, you would take that offset, search for it, change the various pointers that match, and add your art to the new location.

At least I think so.

Guardian · Feb 21, 2006

Neo Chaotikal said:

Did I tell you to paste your art in the same location as on the Sonic 3 ROM? I don't think so. I told you to search for the content of the art found in Sonic 3 on the S&K ROM. If the art is the same, you should get a match. Then, you would take that offset, search for it, change the various pointers that match, and add your art to the new location.

At least I think so.
Click to expand...

:boxing: Oh hell yeah! Of course. How idiotic of me. Your right Neo Chaotikal. I just searched for that offset in the S&K rom. I had many results, but it matched exactly the same. Pasted over my art in that rom, converted it. And what do ya know. It shows up in the S3&K rom. Oh happy day indeed. Thank you very much. Now I can hack over that rom now.

The hacking of Sonic 3 problems

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