What would happen if…

Discussion in 'Engineering & Reverse Engineering' started by MarkeyJester, Apr 30, 2009.

  1. MarkeyJester

    MarkeyJester

    My predecessors have nothing on me. Tech Member
    …we lock a Sonic 2 hack onto Sonic & knuckles?

    As all of you well know, S&K (Sonic & Knuckles) is known for a special lock on system that allows one to lock on any other Megadrive/Genesis game to it, and see the out come, now the only ones really compatible are S2 and S3 (S1 if you want to include the continues loop of blues spheres challenge levels), all other games either don't play or remain as a one level blue spheres challenge,

    Just a little curious to know the outcome of hacks such as “Sonic 2 Advanced Edit” or “Sonic 2 Delta” or something, has anyone with a Flash Cart tried it yet? Or does anyone have a theory of what would probably happen?
     
  2. Chimpo

    Chimpo

    Member Member
    7,310
    0
    16
    Atomic Sonic Part II
    [​IMG]
     
  3. MarkeyJester

    MarkeyJester

    My predecessors have nothing on me. Tech Member
  4. Banoon

    Banoon

    yes Member
    577
    0
    0
    Auckland, New Zealand
    Yeth (hack)
  5. RAMPKORV

    RAMPKORV

    Oldbie Oldbie
    395
    0
    16
    Sweden
    Licking my girlfriend's anus <3
    Locking on with another game takes you to a specific level number. If you complete it with all rings, you get the password to replay that level from Sonic 1 + Knuckles.

    There were also a few games (Forgotten Worlds for example) that didn't even get you Blue Spheres - you just got regular Sonic & Knuckles.
     
  6. Tweaker

    Tweaker

    Misfits
    12,389
    0
    0
    Just locking on Sonic & Knuckles to any available hack won't do anything, and with good reason—all of the code for Sonic 2 & Knuckles is in the 256kb UPMEM ROM, including all of the game's data references. You'd have to do something to the effect of slapping the disassembly of the UPMEM ROM at the beginning of a hack's disassembly and making sure all the data and code references match that of the hack if you want anything to work properly.

    That said, I think it's much simpler to just add the Knuckles object—as well as other desired playable characters—directly into the main game's code. :v:
     
  7. MarkeyJester

    MarkeyJester

    My predecessors have nothing on me. Tech Member
    So there's a possibility that a hack could “In-fact” be made for S&K, but not recommended to bother as it would probably be a waste of time (Not that I'm insanely attempting to of course =$)
     
  8. Tweaker

    Tweaker

    Misfits
    12,389
    0
    0
    Well, yeah—it's definitely possible, by all means; the question is whether or not it's worth the effort on your part.

    Don't be discouraged by me at all, though! It'd certainly be the first of its kind if you were to make something like that, and new things are always fun to see. :v:
     
  9. Blitz

    Blitz

    ¬.¬ Member
    37
    0
    0
    UK
    The HedgehogHack (On hold)
    When I combined my (rubbish) ashura hack with S&K, using gerbilsoft's S&K lock-on thing,
    all of the uncompressed art I had edited hadn't changed, only the pallete. (which had reverted back to normal)
     
  10. Cinossu

    Cinossu

    Administrator Administrator
    2,815
    1
    18
    London, UK
    Sonic the Hedgehog Extended Edition
    Isn't the S2K Upmem ROM something that is essentially built-in to the emulators, though? Considering it's contained on a seperate chip on the cart itself, it's essentially a completely different ROM used. Seeing as S&K is the only known official case of LockOn (isn't it? :x), emulators don't have to make a seperate case for it when loading, and just "load" the chip itself when its needed for that one specific case.
     
  11. MarkeyJester

    MarkeyJester

    My predecessors have nothing on me. Tech Member
    Would that not including “Region Converters” or “Game Genies“?
     
  12. Cinossu

    Cinossu

    Administrator Administrator
    2,815
    1
    18
    London, UK
    Sonic the Hedgehog Extended Edition
    Probably handled the same way SRAM is handled on-cart; set a byte to 1 for access to the game genie/whatever, set it to 0 for access to the main game/rom.

    Also, sorry, talking out of my arse about S2&K, the S2&K rom has the Upmem located at the end of the total 3MB S&K and S2 make together. That address mapping is obviously handled via the cartridge itself normally, but it's just another ROM file addition for us. So.. yeah, Sonic 2 rom hacks could in theory lock on to S&K, but it requires using locations to things exactly as they should be in the Upmem section. Reminds me of the old hacking days of finding code location/indexes, writing a new address or code jump to the end and then back again, etc. Fun times. :3
     
  13. Blitz

    Blitz

    ¬.¬ Member
    37
    0
    0
    UK
    The HedgehogHack (On hold)
    (taken from here: http://info.sonicretro.org/Lock-On_Technology)
     
  14. MarkeyJester

    MarkeyJester

    My predecessors have nothing on me. Tech Member
    well at least I'll have a project task for the future to keep me occupied, when I've finished the projects I'm doing now and have nothing to do =D
     
  15. JoseTB

    JoseTB

    Tech Members Tech Member
    631
    0
    0
    Actually a hack making use of the lock-on "technology" could be interesting with clever usage of the way bluespheres work. For instance, S1 special stages generator based on the serial and a set of chunks :P
     
  16. Dark Sonic

    Dark Sonic

    I'll find the old avatar eventually Member
    12,027
    3
    18
    Working on my art!
    What I was always curious about is could S2&K access all the extra stuff from Sonic and Knuckles? Like could you change the art that's loaded so that instead of like the Sonic 2 title cards loading the Sonic & Knuckles title cards loaded but with the Sonic 2 level name? Or could you somehow start the game off in Mushroom Hill zone after you beat Death Egg Zone (I almost think that plot wise this would sort of work)? Or could you even use Sonic 3 Sonic instead of Sonic 2 Sonic?
     
  17. Hanoch

    Hanoch

    Also known as TheKnock, Birashot Member
    491
    0
    0
    Israel
    everything
    I don't really understand about these things but the maximum size of a ROM is 4mb. If you take a sonic 2 hack, lets say, s2ae and lock it with s&k it will overload the size of the ROM and nothing would happen (because from posts I read in here, s&k is 3mb and s2ae is obviously bigger than sonic 2 itself). Unless you use bankswitching, then you might be able to play knuckles in S2AE.
     
  18. Cinossu

    Cinossu

    Administrator Administrator
    2,815
    1
    18
    London, UK
    Sonic the Hedgehog Extended Edition
    Sonic & Knuckles is 2mb, Sonic 2 is 1mb. The 3mb I was talking about is those two combined, then with the added 256kb at the end for S2&K to work.
    Therefore, you'd need to keep your rom hack within 2mb (and that 256kb after 1mb as the heavily edited upmem with references to your hack) for it to work.
     
  19. Hanoch

    Hanoch

    Also known as TheKnock, Birashot Member
    491
    0
    0
    Israel
    everything
    Exactly what I was saying. If your hack is bigger than 2mb, it will be impossible to play it locked on with s&k. And I am a little wondering, why would someone want to attach s&k to s2ae/s2delta? They already has knuckles in them.
     
  20. Spanner

    Spanner

    The Tool Member
    3,207
    0
    16
    United Kingdom
    Sonic Hacking Contest
    Do note that most of the hacks don't fully feature Knuckles. There are still some things that you need to sort out, such as the special stage and the ending. My port is still buggy and is basically just the Knuckles object itself, no changes to the life icon structure, text stuff or anything else. We have a disassembly but it doesn't work right. I also checked some of it and some stuff was wrong as well. Perhaps somebody should work on getting S2K to work, I did suggest snkenjoi to have a look at it since he made build tools for S3K but he's busy.