Pokémon Stryder7x Edition

PokéStryder is a SRAM hack of Pokémon Red/Blue, dedicated to the Paper Mario glitch Youtuber Stryder7x

Download

Grab this save file, and load it up in your favorite emulator (rename it if you want).

Showcase

Here! (Coming soon: video embed.)

Technical explanation

“SRAM hack”

You are probably familiar with the concept of a “ROM hack”: a modification of a game that offers different content, bug fixes, or an entirely new game; in short, a different game with a similar base engine and maybe assets.

A SRAM hack provides a similar experience, but with a major difference: instead of being a modification of the game’s ROM (code and/or data), the game is the save file. The save file is crafted in a way that the game loads data from the save file, and sometimes it’s tricked into executing code stored in the save file.

The start menu

The most notable “feature” of this hack is the player’s inability to open the START menu. It’s done using OAM DMA hijacking. The hook function checks the video RAM for the top-left corner of the START menu. The function that opens the menu consistently waits for a few frames, so the state of the stack at this point is known, and some return addresses are repointed to the function that closes the START menu.