From Sonic Retro

This page describes an obsolete hacking tool that should not be used for new hacks/projects or with new disassemblies/tools.
This page (and associated files) is being kept for historical purposes only, as it documents and archives the history of the Sonic scene.

ChaoSaX is the ROM hacking tool suite created by Magus (formerly Chaos.) The entire suite is made up of multiple programs for modifying different aspects of Sonic ROMs. Its user-friendly GUI makes it very useful for beginning hackers.


ChaoSaX-Zone is a level editor for Sonic 3K. It has easy navigation buttons on the side to scroll the level. You can view the objects in the levels, and you can even move them around. Unlike most level editors, this program will extract the tiles directly from a savestate, downloading GIF packages of tiles is not required.


ChaoSaX-Stage is a Sonic 3K special stage editor. You can modify any of the 8 original Sonic 3 special stages, and with a unique interface, you can assign an object to a button. It supports 3 mouse buttons. This allows you to limit the need to change the object selection. You can make use of 3 objects at a time with a 3 button mouse. This editor also supports saving and loading Sonic HackingWiz Pro's "S3S" files. Unique to this program is the ability to modify the Sonic 3K bonus stages.


ChaoSaX-Locate is a personal database that will store addresses from a ROM. It comes with pre-loaded addresses, and each address is categorized in a very specific and organized manner. You can type in the address, the range, and the description, and save it to the database. You can even print the entire database list.


Sonic 2 and Sonic & Knuckles both use special compression formats for various data types. These include levels, art, special stages, etc. This specific compression is known as Kosinski compression (named after the person who cracked the format all the way -- Brett Kosinski). The data would be easier to read in a hex editor and modify if it wasn't for the compression. ChaoSaX-Extract will decompress this format for you.


Palette editing is as easy as pie if you use ChaoSaX-Pal. This nifty editor can modify any palette in the Sonic3K ROM. It offers a simple, yet easy to use interface. It has nice sliders to change the colors.

Download.svg Download ChaoSax-Pal
File: ChaoSax-Pal v0.30.7z (11 kB) (info)
Current version: 0.30


Main Article: ChaoSaX-RXL

ChaoSaX RXL Patcher is a utility for patching ROMs using saxman's RXL Format. When programming software for ROMs (e.g. running extra instructions to make the game read/write extra information -- useful for many things such as level editors), bigger problems come in play. Most software add-ons for ROMs are designed specifically to be patched at a precise place in the ROM. If it's not patched correctly, it doesn't work. This is especially bad when you're trying to patch a ROM that already has information at the needed address. Therefore, RXL patching offers an alternative to IPS.