I replaced Animal Crossing's dialogue with a live LLM by hacking GameCube memory

Summary

I Replaced Animal Crossing's Dialogue with a Live LLM by Hacking GameCube Memory A bridge from 2001 to today, with no game code changes required. Cookie: "Oh my gosh, Josh :)! I just had the weirdest dream, like, everything we do is a game! Arfer!" Animal Crossing. Infamous for its charming but ultimately repetitive dialogue. Having picked up the GameCube classic again, I was shocked (/s) to discover that the villagers still say the same things they did 23 years ago. Let's change that. The problem? The game runs on a Nintendo GameCube, a 24-year-old console with a 485 MHz PowerPC processor, 24MB of RAM, and absolutely no internet connectivity. It was fundamentally, physically, and philosophically designed to be an offline island. This is the story of how I built a bridge from 2001 to today, making a vintage game console talk to a cloud-based AI without modifying a single line of the original game's code. The First Hurdle: Speaking to the Game 🗣️ My first stroke of luck was immense. The week I started this project, a massive effort by the Animal Crossing decompilation community reached completion. Instead of staring at PowerPC assembly, I had access to readable C code. Digging through the source, I quickly found the relevant functions under a file named m_message.c. This was it, the heart of the dialogue system. A simple test confirmed I could hijack the function call and replace the in-game text with my own string. C: A glimpse into the decompiled dialogue system // A glimpse into the decompiled Animal Crossing source code // The function that changes message data in the dialogue system. // My initial entry point for hijacking the text. extern int mMsg_ChangeMsgData(mMsg_Window_c* msg_p, int index) { if (index >= 0 && index < MSG_MAX && mMsg_LoadMsgData(msg_p->msg_data, index, FALSE)) { msg_p->end_text_cursor_idx = 0; mMsg_Clear_CursolIndex(msg_p); mMsg_SetTimer(msg_p, 20.0f); return TRUE; } return FALSE; } Easy win, right? But changing static text is one thing. How...