Sonic Adventure Finds...

Discussion in 'Sega Dreamcast Development and Research' started by Woofmute, Feb 6, 2014.

  1. Woofmute

    Woofmute Site Supporter 2013-15, 17

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    It's been a while since I did anything with the Sonic Adventure Autodemo, but I've documented the Chaos 2 fight now that we know how to activate it properly (Credit to MainJP and SpeepsHighway).




    I've also uploaded my current cheat engine cheat table for the Autodemo (to use with demul), this includes things like the title menu id, quicker ways to get to the title without sitting through the intro video, chaos 2's action id, the player's action id, frame limiter and game speed, rings, lives....

    EDIT: Cheat table is outdated, uploading new one to new post.
     
    Last edited: Apr 13, 2018
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  2. darkspire17

    darkspire17 None

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    seems like its mapping what the camera sees as sonic's texture
     
  3. Woofmute

    Woofmute Site Supporter 2013-15, 17

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    Yeah, it uses the screen buffer as a texture which was an interesting effect but i've no idea if it's of much use to anyone for anything
     
  4. Woofmute

    Woofmute Site Supporter 2013-15, 17

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    Cross-posting my post from Sonic Retro:

    An alternative method to start the Chaos 2 battle is to set the byte at 0x8C6A4EAA to 01.
    Activating the fight this way will show the little cutscene that shows the boss' name and activates the health bar, and Chaos 2 will be able to use all of its attacks.
    The punching attack in this version does not have the delay afterwards like the final, so there are less openings to attack.

    The other discovery I'd like to mention is about the demo recorder. It is still mostly functional in this build, and potentially in other builds.
    These demo files are the KEYXXYY.BIN files in the game's data.

    XX is the level ID,
    YY is the level segment ID.

    e.g.
    KEY0501 is Red Mountain, Red Hot Skull.
    KEY0A00 is Final Egg, part 1.

    These use hex values for their level IDs, while SET files use decimal.
    They are loaded into 0x8CBE0000 in memory.

    Demos are recorded and played back only if the value at 0x8C169D18 is 01.
    The current demo read/write location is stored as 4 bytes at 0x8C169D28.
    Setting 0x8C169D1C to 02 stops demo recording and playback, and prints the current read/write location of the demo to the screen.

    Demos can be recorded and dumped by setting this byte to 02 when you're done, and dumping the memory from 0x8CBE0000 to wherever the printed location is.

    The KEY files are the same format as the memory dump, and should be easily replaceable.
    Custom demos will most likely need a footer like the KEY files in the game's data have, which I believe is the last 12 bytes of the KEY file.

    Sonic in Speed Highway Footer:
    FFFFFFFF 00000000 090080FF
    E-102 in Red Mountain Footer:
    FFFFFFFF 00000000 7E001100

    Will be looking for this in other versions soon.

    I've attached a new cheat table that includes the addresses for the demo recorder and for activating the full Chaos 2 fight.
     

    Attached Files:

    Last edited: Apr 13, 2018
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  5. darkspire17

    darkspire17 None

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    Litteraly used for nothing, i tend to complete and replay SA1 Basicly 6 times a week (yes i love the game that much) and its used on nothing as far as im aware, may have been used as a reflection unction at one time, since SA1 uses images of the enviroment as a reflection texture, at one point it could have had real time reflections
     
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