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Game Saves collect project

Discussion in 'Saturn Dev' started by vbt, Jan 10, 2016.

  1. paul_met

    paul_met New Member

    I need a corrupted Backup RAM file so that the game can not initialize it and asked to format it (it is necessary to call such messages in the game itself). Or how can I corrupt the Backup RAM file for this?
     
    Last edited: Oct 1, 2018
  2. cafe-alpha

    cafe-alpha Member

    Please try by filling start of internal backup memory (from address 0x00180000) with random values : start of backup memory contains "BackUpRam Format" signature and I suppose that it is recognized as corrupted if signature is not set there.
    If this doesn't works, please try by settings random value after the signature area (= from 0x00180080), because (if I remember correctly) partition table for each memory blocks is stored there.
     
  3. paul_met

    paul_met New Member

    Nothing. I filled the blocks with random values from address 180000h to 1800A0h, but did not get the desired effect. At least Yabause does not react to this.
     
  4. cafe-alpha

    cafe-alpha Member

    There two different error codes for corrupted save on Saturn backup library : BUP_UNFORMAT and BUP_BROKEN.
    And it seems that corrupting the backup RAM signature throws BUP_UNFORMAT, so if you want to trigger BUP_BROKEN error while reading a save data, modifying save data allocation table and/or save data size should do the job as detailed in the screen copy below :
    [​IMG]


    Here is the save data file used for testing : http://ppcenter.webou.net/divers/20181006_bup_broken_bkram.7z
    Acecssing the KAKYUSEI__2 file throws a BUP_BROKEN error code.
     
  5. paul_met

    paul_met New Member

    Thank you, but in this case in the game I get a standard warning about the lack of free space. But I need the remaining two messages about the need to format memory cards (internal and external).
     
  6. cafe-alpha

    cafe-alpha Member

    My previous post was just to show how to trigger this BUP_BROKEN error. Which game needs theses corrupted save files ? And if possible, can you provide a working save file for it ?
    If you provide theses informations, I would gladly corrupt the save files :)
     
  7. paul_met

    paul_met New Member

    Ok, here a save file for game Device Reign.
     

    Attached Files:

  8. cafe-alpha

    cafe-alpha Member

    I changed the save data size and allocation table are set to nonsense values, so it should trigger an error when reading.

    It may take one day or two before I can test with the game, so if you are faster please keep me informed if it works or not.
     

    Attached Files:

  9. paul_met

    paul_met New Member

    Yes, the message about formatting the internal RAM is displayed, but only if you start the game on the SSF. For some reason this does not happen on the Yabause emulator - the game starts without any warnings. In this regard, I can not debug it.
     
  10. cafe-alpha

    cafe-alpha Member

    I tried here too, but I only get a black screen on startup; I'm using a slightly modified version of yabause, which have probably worse compatibility than vanilla version however.
    Maybe you could try with forks of yabause (example : Kronos or Yaba Sanshiro), but since they usually don't memory editor or disassembler I guess theses are similar as SSF = "meh, what am I supposed to do with that ?" ...
     
  11. paul_met

    paul_met New Member

    So, by comparing the memory dumps of the SSF emulators and Yabause, I found the values that are responsible for warning messages. I solved this problem. Thanks for the help.
     

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