Sonic Crackers (Stadium) Hack?

Discussion in 'Engineering & Reverse Engineering' started by Retro_Stew, Mar 13, 2014.

  1. Retro_Stew

    Retro_Stew

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    Hi,

    So, I was wondering... I recently bought some cartmodding tools to make my own Megadrive and Snes games, and I really wanted to make a real copy of Sonic Crackers.
    It worked, it's nice and all, but as said on the wiki, the game crashes at the SEGA screen (if I don't pass it with start), or at random locations.

    Is there a Sonic Crackers hack to fix these issues? And has someone ever worked on a hack to make the proto more playable, like Chaotix?

    Thanks :)
     
  2. MarkeyJester

    MarkeyJester

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    If you have a hexadecimal editor available, open the ROM. Go to offset 000412, replace 50 00 with 4F D6. Then go to offset 004FD6, replace 10 00 67 33 8B 00 00 31 8B C9 70 23 40 00 00 00 23 00 00 72 32 D8 E5 E4 00 40 48 02 00 23 00 00 23 00 00 13 00 00 4E 10 00 67 with 4E B9 00 00 51 8A 70 02 72 FF 51 C9 FF FE 51 C8 FF FA 10 3C 00 82 4E B8 64 02 32 3C 40 00 51 C9 FF FE 10 3C 00 E1 4E B8 64 02. Finally, go to offset 006432, and replace 4E B9 00 00 51 8A with 4E 71 4E 71 4E 71. That will prevent the ROM from crashing on hardware.
     
  3. Retro_Stew

    Retro_Stew

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    Ok thanks, I'll do that next time I flash the rom!
     
  4. Dark Sonic

    Dark Sonic

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    Since that was solved, I have a question about flash roms. What are they, how do they work, and where can I get one, because I would love to put Sonic 3 Complete on a cartridge and play it on my Genesis.
     
  5. Tanks

    Tanks

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    We should really have a pinned Flashcart topic since developments seem to come out of the blue...
     
  6. Overlord

    Overlord

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    Everdrive is what you want, see a feature list here: http://krikzz.com/

    However I couldn't tell you which of the two on that page is the better one, my flashcart is an older Tototek that I've not seen an immediate need to replace. http://atariage.com/forums/topic/127752-flashcart-and-multicart-list-all-systems/page-28#entry2498499 may be of some help.
     
  7. Aerosol

    Aerosol

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    Everdrive is for if you want a multi-cart.

    Get yourself a repro if you it to feel a bit more genuine.
     
  8. Iggy for Short

    Iggy for Short

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    It's insane how much they charge for flash carts...
     
  9. Overlord

    Overlord

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    Not really, they'll pay for themselves after a few ROMs. Especially rarer ones.
     
  10. Retro_Stew

    Retro_Stew

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    Well, it's not quite solved, I still want to know if someone is willing to make a hack based on Sonic Crackers to make it more playable / like a real game.
     
  11. JojHeywood

    JojHeywood

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    Sonic Classic Heroes implemented Sonic Crackers/Knuckles Chaotix gameplay not too long ago if that tickles your fancy.
     
  12. Felik

    Felik

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    Dude it only has 2 stages. If anything it'd be reasonable to use it's graphics for a level in some hack or fangame.
     
  13. Retro_Stew

    Retro_Stew

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    A lot of fan hack only have two stages in their first (and generally final) version.

    It would be interesting to make some levels with modified tiles from Chaotix, for example. Like if they took the direction to make the Chaotix game a true Sonic sequel on genesis instead of a spin-of.
    I'm curious of the lack of "hacking interest" for this prototype (compared to Sonic 2 alpha/beta, for example)

    Plus, I'd be curious to know how the map screen could be used/modified.
     
  14. ICEknight

    ICEknight

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    Speaking of, has anybody looked for any unused functionality in there, such as jumping or collision detection?

    I remember finding an unused flashing palette in the "electric" field back in the Genecyst days, but I haven't seen it documented anywhere yet, so there might be more stuff in there still waiting to be discovered.
     
  15. Retro_Stew

    Retro_Stew

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    So, sorry for the bump, but it didn't really work.
    I tried to edit the rom, it was still working on Gens. Then I flashed on a cartridge...

    The game doesn't freeze anymore on the Sega screen, but after pushing start on the title screen, the game kinda freezes on a blue screen with Techno Tower music, then eventually crashes.
    Is there something I could have done wrong? My hardware is a european Megadrive, but switched, so I tried in 50/60 Hz, and US/Jap.

    Thanks in advance...
     
  16. MarkeyJester

    MarkeyJester

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    The original crash of Sonic Crackers on hardware was caused on the Z80 side (in this situation, the sound driver). The fact that the game has crashed, but the music resumes playing means that it's something else this time around. Just to be sure, I triple checked my fix on a clean ROM, and tried it on hardware:

    [​IMG]
    [​IMG]

    My machine is also european, and I also tried with the addons removed for clarity (not that that should matter at all). There are selections in the level select that have been known to do what you describe, but never directly from the title screen. Are you sure you followed the instructions to the letter? And are you sure the ROM was written to your cart correctly? Crackers has no checksum comparison routine, so if a part of the ROM was not written correctly to the cartridge, then Sonic Crackers won't pick up on that.
     
  17. Endri

    Endri

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    MarkeyJester, what an absolutely wonderful setup!

    ICEknight, in fact, there are! IIRC, when I was porting Knuckles' Chaotix/creating a reassemblabe disassembly and looking at Sonic Studium for comparisson(s) a long while ago, off the top of my head, the subroutines equivalent to Obj1_SlopeResist and Obj1_SlopeRepel are dummied out.
     
  18. Retro_Stew

    Retro_Stew

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    Oh! Then I guess I made some mistake? That's weird. Talking about the checksum, I did fix it with a software after editing the rom and before swapping the bytes. Maybe I shouldn't have?
     
  19. MarkeyJester

    MarkeyJester

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    Well... changing the checksum value in the header will have no effect, but it's what else it might attempt to change without your acknowledgement. But since there's no software in the ROM that checks the sum of the ROM, running a fix is pointless, so I wouldn't really bother with it.
     
  20. ICEknight

    ICEknight

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    Hmm, interesting.

    If only those routines were the same ones that made it to 3D Blast, perhaps there could be a way of porting them back or something... But yeah, I don't think so. =|