Cheat engine documentation and patching ROM-mapped memory?

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Vulnix
Posts: 1
Joined: Sun Jul 03, 2022 11:39 pm

Cheat engine documentation and patching ROM-mapped memory?

Unread post by Vulnix »

Hello world, I have two questions regarding the Cheat Engine: one on documentation, and one on what regions of memory it can write to. For context, I'm trying to translate a cheat for Pokemon Emerald (GBA) that makes it easier to get pokerus, and all the existing cheats I've found for other platforms all require patching ROM memory. I've validated that the cheat works using the debugger in mGBA, so I'm certain my issues are with the Mister cheat engine.

For the documentation question, I was trying to make a GBA cheat, and was wondering if there was more in-depth documentation on the cheat engine than this wiki page. Is there more thorough documentation that describes the full list of options for the first dword, and documentation on how many bytes of the last dword are written to memory? For instance, I saw both 0x30 and 0x31 in the first dword being used in the cheats downloaded from GameHacking.org, but couldn't find documentation for what that meant. Additionally, since I'm trying to make a cheat for a 16-bit GBA game, it's not clear whether the cheat engine only takes one byte, two bytes, or all four bytes from the last dword of the cheat instruction to write to memory.

For the second question I had, I was trying to write a cheat that requires patching the ROM section of memory (0x0800_0000 - 0x09FF_FFFF on the GBA for this game), since the easiest way to implement it is just to change one of the game's instructions. I noticed that wasn't working with the Mister GBA core. Does the Mister cheat engine support overwriting the ROM-mapped section of memory?

Thank you for any insight you might have to offer :)
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