don't click here

Water, water everywhere...

Discussion in 'Engineering & Reverse Engineering' started by Quickman, Jan 22, 2004.

Thread Status:
Not open for further replies.
  1. Quickman

    Quickman

    be attitude for gains Tech Member
    5,595
    18
    18
    :x
    omg porjcet
    I was thinking wishy-washy thoughts, and my attention came to water. I thought, "How does water work in Sonic 2?" So I did some research and came to a small snippet of code consisting of two BEQ commands, two CMPI commands, a BNE command and a MOVE command. This was the method by which the game decided whether or not to load water for a specific level. Then I thought "How do I change which levels load water?" More research revealed a complicated process which was difficult. So I thought "Surely you can just change the various commands - BEQ, CMPI, BEQ, CMPI, BNE, MOVE - for a single BRA command? That would always load water, surely?"

    So am I right? If not, why not?
     
  2. Quickman

    Quickman

    be attitude for gains Tech Member
    5,595
    18
    18
    :x
    omg porjcet
    Uh-oh, double-post time.

    I've made a hack which basically changed the last Break if Not Equal (BNE) command to point to the same thing as the previous Break if EQual (BEQ) commands. The result: Water, water everywhere, and glitches to make us think. I'll put up a link to my little hack and let you lot do the testing. I've already tested EHZ1 a little, and found two glitches:
    • If you manage to get to the top of the screen, the graphics which would ordinarily be the waves on the surface show up as bits of Buzzer.
    • The knob-like things at the ends of bridges kill you underwater. I have no idea why though.
    Here's the hacked ROM.
     
  3. NickW

    NickW

    Member
    The link is broken bro.
     
  4. Quickman

    Quickman

    be attitude for gains Tech Member
    5,595
    18
    18
    :x
    omg porjcet
    So it was. It;s fixed now though.
     
  5. Timecrash

    Timecrash

    I, Timecrash, will knock you all down! Member
    Cool, I've always wanted to be in Atlantis!
     
  6. Simon

    Simon

    Oldbie
    LOst can probably help you with this...

    btw the B in BNE, etc, is "branch", not "break".
     
  7. LOst

    LOst

    Tech Member
    4,891
    8
    18
    Water can be loaded in most levels. There is a "water guide" at Sonicology. You should read it. It has already been done :)
     
  8. Hivebrain

    Hivebrain

    Administrator
    3,068
    204
    43
    53.4N, 1.5W
    Github
    I think you mean SSRG. I don't have a water guide.
     
  9. Quickman

    Quickman

    be attitude for gains Tech Member
    5,595
    18
    18
    :x
    omg porjcet
    I tried to follow the guide at SHacNet, and it kinda... didn't work. Unless my "start water here" figure was wrong. I'll copy the water height for CPZ2 or ARZ and make it work, but the SHacNet guide is too patchy and involves too much "oops, forgot this". They could simply tell you how to do it without saying "put bb- oh no, put eeee".

    Nonetheless, thanks very much.
     
  10. Icy Guy

    Icy Guy

    Hedgehog. Sonic the Hedgehog. Member
    776
    0
    0
    California
    GoldenEye 007 level hack
    Out of curiosity, what disassembler did you use? I'm interested in taking a peek around some of my Genesis ROMs (read: Sonic), and that interest may turn into something more later on.
     
  11. Quickman

    Quickman

    be attitude for gains Tech Member
    5,595
    18
    18
    :x
    omg porjcet
    I used 68kd. Nemesis knows where it can be found, and he's posted numerous times on the subject in a topic on assembly code in the Sonic Cult forums.
     
  12. Everlast

    Everlast

    Pending Member
    1,200
    0
    0
    The Bridges always kill me
     
  13. Icy Guy

    Icy Guy

    Hedgehog. Sonic the Hedgehog. Member
    776
    0
    0
    California
    GoldenEye 007 level hack
    Gotcha. Thanks. :)
     
  14. Quickman

    Quickman

    be attitude for gains Tech Member
    5,595
    18
    18
    :x
    omg porjcet
    Yeah, they kill me too. Don't bother with that ROM anymore though. Just a small exercise in pointlessness, and a good bit of fun too.
     
  15. superstarCSB

    superstarCSB

    snootch Member
    621
    0
    16
    Lawrence, Kansas
    I probably should get back to work on my site someday...
    Check out this save-state. It's after I finally beat the first level (quite a challenge with all the water). Download the water rom and use this savestate, once you enter the second stage, Sonic automatically dashes and goes right into the ground. (Try jumping at that point, and Sonic will get launced into the air, land on the ground yet lose rings, and then when he touches the ground again, he dies. This kinda reminds me of the Sonic 1 spike bug!) Also another werid thing, go ahead and get game over and let it start over (don't thouch anything!), after the title screen shows, it'll start the demo of the first stage. Then in a split second it automatically goes to the stage select. Pretty cool! And yet one more thing. Upon entering the stage select, pick a stage and it will play a demo of it for you! Actually Sonic runs around like he's in the first stage I believe, no matter what stage you pick.
     

    Attached Files:

  16. Pretty funny hack, Quick.
     
Thread Status:
Not open for further replies.