Welcome to SonED2, the Sonic the Hedgehog data editor. SonED2 is the successor to the original SonED utility, with
added and enhanced features, and much greater stability. It contains various editing features designed to help create
all-new levels for the original Sonic the Hedgehog series of games.
The following is a list of the other documents in this set, each of which
provide functionality and usage details about certain SonED2 features:
Basic Usage Overview
Unlike its predecessor, SonED2 is designed to work with individual
files, which means that data has to be extracted before editing, and
then reinserted when editing is complete. This allows the user to have
more control over their data layout, and also allows for making changes,
additions, and deletions that alter the data size without having to
worry about hardcoded placement systems overwriting other data or code,
leaving unnecessarily large unused gaps, or creating conflicts with other
Because SonED2 edits individual files, it is "project"-based, meaning
that it is necessary to obtain or create a "Project File" that specifies which data
files should be loaded and how they should be interpreted. "Project Files" are plain text files, although
they are given the file extension .sep to identify them to SonED2 and
the user. These files contain the filenames of the data files required
to begin a particular editing project, and a few settings values when
necessary. Different types of projects use different formats for the
"Project File", which are explained by the "Project File" documentation.
At program-start, a logo screen is presented as a placeholder until a
"Project" is loaded. Using the file menu, open a "Project File", and
if the data in that file is correct, the appropriate editor will start
and the data referenced by the "Project File" will be displayed and
ready for editing.
The "Save Project" selection will save all currently-loaded data to the
files specified by the "Project File" that was used to open them. For
reference, the path and filename of the "Project File" are shown in the
window's titlebar. The "Project File" may be altered before using "Save
Project" if different names are desired. Pressing F3 will also save the
For editing specifics, please refer to each editor's documentation.
This is an advanced tool for advanced users, so less experienced users
shouldn't expect to delve straight in without having a few problems.
Reading and understanding all documentation is essential.
Simplified Use With ROMulan Integration
As an alternative to fully manual data placement, SonED2 includes
ROMulan functionality. This allows the use
of modifiable and expandable scripts to specify unused and otherwise
disposable sections of the target file into which the data may be
placed without the risk of creating conflicts, and at the same time,
automatically update all references to the data for their new locations.
SonED2 is accompanied by such scripts for several of the games it supports,
which include only what is required for level layout and level graphic editing.
However, the existing scripts may be modified and augmented with additional
scripts to allow for the simultaneous placement of other data, as well. Combining
scripts for simultaneous injection of multiple data types will eliminate the risk
of conflicts in placement that could occur between separate utilities or injections.
Each of the included ROMulan Extract/Inject script sets also includes
a full set of default project files for the game for which it was designed.
Usage is very simple:
- Navigate to the SonED2 folder to find and unpack the archive for the desired script set.
- Follow the script set's instructions as to what game file to copy, where to copy it to, and what filename to give it.
- Use SonED2's "Run Batch" File Menu option to run the set's "split" script.
- Use the "Open Project" File Menu option to load the project file for the desired level.
- Edit the level in any way as described by the SonED2 documentation.
- Use the "Save Project" File Menu option or the F3 key to save the level project. This is imperative; by nature, ROMulan uses only files stored on the disk, not the data currently-loaded into SonED2.
- Use SonED2's "Run Batch" option to run the set's "inject" script.
- Test the resulting game-file(s), whose names are given by the script set's documentation. The process is now complete.
Sonic the Hedgehog and all related material that is supported by SonED2
remain property of Sonic Team / SEGA. Any other material that may share
similar data formats are likewise the property of their respective creator(s). SonED2 is intended for
use as a creative tool, not full-scale copyright infringement. Use of
SonED2 in violation of any law is strictly a decision on the part of the
end-user. The user agrees to take sole responsibility for such actions,
and as such, implies that they are aware of applicable laws and penalties.
License to use and distribute this utility freely is granted only under the following conditions:
- Any material whose creation is due in any way at all to SonED2 may not be exchanged for profit, regardless of the content of the material or the authors' legal status in relation to any existing intellectual property. In order to use SonED2 for any profitable and/or commercial purpose, special license must be obtained from SonED2 author Stealth.
- Any projects making use of SonED2 should in some way credit the utility and/or Stealth. It is preferable, at minimum, that this reference be made in addition to any other existing credits listing under a heading such as "Utilities".
- Any redistribution must be made freely, requiring no form of compensation whatsoever, and may not be included as part of any sort of package.
- Any redistribution must not be modified; SonED2 may only be redistributed as it was originally packaged. The archive, its file contents, and the files themselves must not be modified in any way, and may not be accompanied by any material that was not a part of the original distribution.
Special permission is granted to host or otherwise reproduce this documentation in viewable form on any site that hosts redistributions of SonED2, so long as none of its contents are modified, omitted, or ammended.
Official Site and Discussion Forum
SonED2 and ROMulan updates will be noted on the Organized Chaos homesite:
The following is the official SonED2 homesite:
Visit the official forum for bug reports, usage and support discussion, and discussion of projects created using SonED2 and ROMulan:
SonED2 is created by Stealth (firstname.lastname@example.org) of Organized Chaos. Please make note in any project
for which SonED2 is used.
SonED2 uses the KENS compression/decompression library, created by
David Declerck (ChaosIsLight@aol.com) using code and methods developed
by various contributors. For more information, please see the KENS
documentation. The DLL versions distributed with SonED2 were modified by Stealth
and jman to correct for data and crash errors that were discovered after some of the functions
were put to more extensive use; please be aware that replacing these files is likely to cause instability
and data corruption under certain conditions. Use of any other versions of these files is not supported.
Special thanks to:
The Chaos Emerald
Damian Grove / Saxman
Any other past or future contributors