Retro Gaming

Reversing Nintendo ROMs is a fascinating world of retro game hacking. In this blog post, we’ll dive into the process and tools used to understand and modify classic games.


Nintendo has a rich history of iconic games that have captivated players for decades. But, have you ever wondered what makes these games tick? Reversing Nintendo ROMs is the key to unlocking their secrets. In this post, we’ll explore the world of retro game hacking by examining the process of reverse engineering Nintendo ROMs.

What are ROMs?

ROM stands for Read-Only Memory. In the context of gaming, a ROM is a file containing the data from a game cartridge. This data can be used by emulators to run the game on modern hardware. ROMs are the foundation for our reverse engineering journey.

Tools of the Trade

To get started with reversing Nintendo ROMs, you’ll need a few tools:

  1. Emulator: A software that allows you to run the ROM on your computer. For Nintendo consoles, popular emulators include FCEUX for the NES and ZSNES for the SNES.
  2. Hex Editor: A tool that allows you to view and edit the binary data of a ROM. HxD is a popular hex editor for Windows.
  3. Debugger: A tool that allows you to step through the game’s code and analyze its execution. Many emulators include built-in debuggers.
  4. Disassembler: A tool that translates the game’s machine code into human-readable assembly language. IDA Pro is a powerful disassembler that supports many processor architectures, including those used in Nintendo consoles.

Understanding the Game’s Architecture

Before diving into the ROM itself, it’s crucial to understand the architecture of the game console. Each console has its own unique processor and memory layout. For example, the NES uses a 6502 processor, while the SNES uses a 65C816. Understanding the underlying hardware will help you make sense of the game’s code.

Disassembling the ROM

Once you have a firm grasp on the console’s architecture, you can begin disassembling the ROM. This process involves loading the ROM into a disassembler and translating the machine code into assembly language. This will give you a clearer picture of how the game’s code functions.

Debugging and Modifying the ROM

With the disassembled code in hand, you can start exploring the game’s inner workings. Using an emulator with a built-in debugger, you can set breakpoints, step through the code, and analyze the game’s logic. This is where the real fun begins, as you can modify the game’s behavior and create your own custom hacks!


Reversing Nintendo ROMs is an exciting journey into the world of retro game hacking. With the right tools and a solid understanding of the game’s architecture, you can unlock the secrets hidden within these classic games. Whether you’re looking to create custom modifications or simply learn more about your favorite titles, the world of ROM hacking awaits.

Enjoyed this post? Stay tuned for part 2!