DRS Resource Builder/Extractor Utility

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Note that this is a command line utility, so you have read the description in order to use it!

This is the content of the readme file:


DRSBUILD Version 1.0 - MS AoE DRS Resource Builder/Extractor Utility

Copyright (C) 1997 Stoyan Ratchev. All rights reserved.

Written by Stoyan Ratchev, sratchev@mail.techno-link.com

Posted to: AoE Heaven, http://age.gamestats.com/age/
           Empire of Ages, http://www.mordor.ch/user/cartho/age/
This program is freeware. Please e-mail me for bug-reports, suggestions and comments.

Age of Empires a game by Microsoft & Ensemble Studios. All trademarks are property of their respective owners.


Usage - Examples
Practice - Creating Modpacks with DRSBUILD - Installing Modpacks with DRSBUILD - Dangerous commands
Changes - Version 1.0 - Version 1.1
Bugs & Limitations
Future Upgrades
Feedback and Support


DRSBUILD is a command-line utility for building MS Age of Empires data resource (.DRS) files from wave sound (.WAV) files, shape graphics (.SLP, .SHP) files and various binary (.BIN) files. It supports such actions as: adding/replacing files in data resource files, deleting files from data resource files, extracting files from data resource files and listing files contained in data resource files. The command-line interface of DRSBUILD features full wildcards support, which means that all actions can be performed on multiple sound, graphics and binary files, and target data resource files, and will affect only the files matching the specified wildcard arguments.

The primary goal of DRSBUILD is to make possible the creation and use of AoE modpacks. A "modpack" (modification package) is a set of modified graphics, sounds and rules that should replace the standard ones and make a game to look and feel differently, while retaining the same game engine. Modpacks are available for many of the most popular games - Civ2, Warcraft, DOOM, Quake, etc. Anybody who has played a good modpack knows that by editing the game resources the best game can be made even better! I've played many Civ2 modpacks that I loved more than the original game, so I feel that the same thing for AoE is a must. That's why I decided to write a builder/extractor utility for the AoE data resource files. This utility can be used by modpack developers and modpack users to achieve an unexpected AoE experience.

Since the graphics & sounds of AoE are packed in data resource (.DRS) files, their direct replacement is not possible. Furthermore even if somebody invents a way to modify the data resource files by replacing some of the files contained within them with other files, he couldn't share his work with others without great difficulty, since the data resource files of AoE are very large (total size 46.4 MB). Here is where comes the need of such an utility like DRSBUILD - with it the extraction, modification and replacement of the files embedded in the .DRS files is an easy and straightforward task. Modpack developers can experiment with every one of the 683 graphics and 144 sounds, as well as with the user interface of 24 dialogs, 108 graphics and 17 sounds, by modifying or replacing some of them to make specific scenario or campaign more attractive or just to let people have fun. After finishing their work, they can provide to others only the files they have modified, not the whole 45MB resource set. Modpack users on the other hand can put the modified files into the data resource files with a single command-line invocation of DRSBUILD, or even better by running an install script (.BAT file) which makes backup copies of the original .DRS files, installs the modpack by invoking DRSBUILD and finally tells the people to enjoy and how to restore everything as it was. A sample modpack installation script is provided in the file MINSTALL.BAT.

If you are still in doubt if all this can be possible, you can stop reading for a while, surf to AoE Heaven and download from there "First Age of Empires Modpack" made with DRSBUILD. This sample modpack contains 2 new files - 1 graphic for the Egyptian wonder and 1 sound for the wonder selection. There are also installation/deinstallation scripts and a sample scenario to test the modpack. After installing it and successfully defending your new differently looking and sounding wonder in the sample scenario, you can continue reading this and other documents that come with DRSBUILD to see how it was created and how you can create your own modpacks, much better than this, or use modpacks created by others.

Here we come to the bad news. You can't edit the graphics files (.SLP and .SHP) even extracted from the .DRS files - their format is proprietary to ES and is too complicated to be dug out by hackers. There are no utilities for editing and converting this format and will never be, unless ES supplies them. However, according to Matt Pritchard, the ES graphics engine specialist, there is a high probability for that. So you should wait for it to edit the graphics, and me to remove this sad paragraph from this text. As for the new Egyptian wonder graphic I used in the "First Age of Empires Modpack", I took it from the data resource files of the game - it was there, #30 in GRAPHICS.DRS, not used and unseen by nobody. There are several other like it that you could use for the same purpose, but of course the possibilities are limited.

To do whatever customization you want, you need to know what to modify. The files embedded in the .DRS files are identified by their type - .BIN, .SLP, .SHP or .WAV, and by integer numbers (file identifiers). These numbers are of course not very descriptive by themselves. I'm currently preparing a table containing the descriptions of most files from SOUNDS.DRS and GRAPHICS.DRS and some from INTERFAC.DRS. It will soon be available for download on the AoE Heaven and Telcontar's AoE sites, and will probably be included in the future DRSBUILD versions packages.

The history of DRSBUILD is interesting. I didn't discovered the .DRS files format myself. I found a somewhat incomplete (and slightly incorrect) description in the Telcontar's AoE site, written by Cyrille Artho and Steve Chen. I was grabbed by the idea, so I filled the blanks in their description of the DRS format and wrote the first version of DRSBUILD. It contained a detailed description of the .DRS files format as I understood it. It was pretty full except for a single mysterious byte. After that an email from Matt Pritchard (ES) clarified it all. His description is of course the most adequate one, but at least for now is considered a document to be used only by AoE utility developers. Since I had already written my own description, I simply slightly corrected it to make it full. It is provided in the file DRSFMT.TXT.

Please note that this software is comes with ABSOLUTELY NO WARRANTY of any kind, so use it at your own risk.

Microsoft (MS) and Age of Empires (AoE) are trademarks of Microsoft Corporation. All other trademarks are property of their respective owners.


It's very simple. The original package is a ZIP archive called DRSBLD11.ZIP, which contains the following files:
DRSBUILD.EXE 		- executable
DRSBUILD.TXT		- the file you are currently reading
MINSTALL.BAT		- sample modpack installation script
DRSFMT.TXT			- description of .DRS files format
After unzipping the archive, copy the executable to a location somewhere in your PATH, so you can use it without specifying its full name.


DRSBUILD is a command-line (console) utility. This means it's intended to be run from a MS-DOS prompt, and with correct arguments. Don't try to click it in the Windows Explorer - nothing will happen. Read the description that follows to learn about the DRS operation modes and command-line switches.
Usage: DRSBUILD {/a | /r | /d | /e | /l | /h} <drs_file>[.DRS]
                [<file> ...] [/o <out_dir>] [/s]

    /a  Add/replace files in <drs_file>
    /r  Replace files in <drs_file>
    /d  Delete files from <drs_file>
    /e  Extract files from <drs_file>
    /l  List files in <drs_file>
    /h  Print a help screen

    /o  Extract files to <out_dir> folder, default is current folder
    /s  Silent mode
All commands (except "/h") work on one or more .DRS files which must follow the command. This is the <drs_file> argument. It must be a valid file specification for the Windows 95 operating system and can contain "wildcards". These are the characters "*" or "?", where "?" stands for "any character" and "*" stands for "zero or more any characters". If <drs_file> is a filename (no wildcards) the .DRS extension can be omitted, and the file is not required to exist if the "/a" command is given - in this case a new .DRS file with the specified name is created. If <drs_file> contains wildcards (e. g. "*.drs") then it should be possible to be expanded to one or more existing .DRS files, even if the "/a" command is given - in this case all commands work on all existing .DRS files matching the specified wildcard argument.

Besides the command and the .DRS file(s), you can specify any number of file specifications for the files which the command should process. These are the <drs_file> arguments. They can also contain wildcards (e. g. "*.wav"). If "/a" or "/r" commands are given, the <drs_file> arguments are assumed to be existing external files which should be added to or replaced in the specified .DRS file(s). Otherwise, they are assumed to be "internal" files, i. e. contained within the specified .DRS file(s), which should be deleted, extracted or listed. If there are no <drs_file> arguments given, they assumed to be "*.*", i. e. all files in the current folder. If you don't know the filenames of the internal files, use DRSBUILD with the "/l" command to see them.


To extract all files from the DRS file INTERFAC.DRS, located in the folder \GAMES\MSAOE\DATA type:

  DRSBUILD /e \games\MSAoE\data\interfac.drs
To build the DRS file INTERFAC.DRS in the current folder from the all files in the folder INTERFAC\ type:
  DRSBUILD /a interfac.drs interfac\*.*
To delete all .SHP files from the .DRS file INTERFAC.DRS in the current folder type - don't try the game with this version of INTERFAC.DRS :-) :
  DRSBUILD /d interfac.drs *.shp
To replace only the existing files in all .DRS files in the folder \GAMES\MSAOE\DATA with the corresponding (matching file identifiers) files in the MY_MODPACK\ folder without adding new files type:
  DRSBUILD /r \games\MSAoE\data\*.drs my_modpack\*.*
To list all files in the DRS file INTERFAC.DRS, located in the current folder, type:
  DRSBUILD /l interfac.drs
Wildcards are supported when specifying the files to be included.

NOTE: If your files have long names with spaces, you should place them in "".

NOTE: In the older versions of DRSBUILD, the "Add/replace" command was called "Build" command and the switch was "/b". It's still there and works in the same manner as the "/a" switch. It is provided for backward compatibility only.

The filenames of the files contained within a .DRS file can't be determined from the .DRS file format. Each file is identified by an unique integer number, which serves as an identifier for the file. When extracting or listing, the filenames are constructed according to standard namespace rules in the following manner: the name contains 8 symbols, the first 3 of them being the same as the first three symbols of the .DRS filename, the next 5 containing the file identifier, padded with zeros from the left if less than 10000; the extension of course is ".BIN", ".SLP", ".SHP" and ".WAV" according to the file type. For example, the wave file numbered 5148 from SOUNDS.DRS is named SOU05148.WAV. When adding an external file to a DRS file, DRSBUILD expects the file identifier in the last 5 symbols of the filename and the type in the extension, the first 3 letters being not important. That is you can replace #5148 in SOUNDS.DRS with AOE05148.WAV or WAV05148.WAV, but not with SOU5148.WAV or WHATEVER.WAV. If a non-compliant external filename is encountered, it's error. This is made on purpose, to prevent as much as possible the building of corrupted DRS files that could crash the game and hang the OS.

During the work of DRSBUILD, you'll see messages on the screen about the operation currently in progress. If an error occurs, a message is displayed and the program execution is stopped. Possible errors include failures to open, read from or write to some of the files that were specified, wrong usage, or attempt to use invalid input files or non-DRS files as targets. The type of the DRS files is determined from their extension and from their header. The extension of the DRS files must be always ".DRS".

No matter the command, the .DRS files are not required to reside in the AoE DATA\ folder. The output files are created in the current folder, unless otherwise specified in the <drs_file> argument and the "/o" switch. To use the .DRS files with AoE, you must copy them by hand to the DATA folder where the game was installed. After doing so, simply start the game and enjoy.


How you should practically use DRSBUILD to create or install modpacks? These are two completely different tasks, the creation being a major trouble for modpack developers, and the installation for modpack users (or modpack developers when writing installation scripts for their modpacks). I have therefore divided this section into two parts for these two tasks. Don't skip it, reading it can save you lots of trouble.


First of all, you need to determine what files you should change. You need to know the file identifier of each file in order to do this. Refer to the file DRSFILES.TXT (will be available in a few days for download) or some other description of the .DRS files contents to learn them. Each identifier corresponds to a given object or event, for example the Egyptian wonder graphic is #33 in GRAPHICS.DRS and the wonder selection event sound is #5148 in SOUNDS.DRS. If you replace some of the files in the .DRS files with files in the same format that the game expects for each particular file, that is .SLP for the graphics and .WAV for the sounds, the game will use the modified ones. In fact this is your chance to create modpacks.

If you want to take some of the standard files as a base for creating your own, you must extract them from the .DRS files of the game first. Use DRSBUILD with the "/e" switch to do it. For example to extract all embedded files from all .DRS files of the game (installed in the \GAMES\MSAOE folder) in the FILES folder type:

  DRSBUILD /e \games\MSAoE\data\*.drs /o files
Next you should edit the standard files, or create/obtain the files with which you them to be replaced. As for the sounds, you can take any .WAV file you want, record it or create it some other way. Be careful though - some sound editors produce .WAV files in a slightly incompatible format, they do not crash the game, but are never heard. The Windows 95 Sound Recorder appears to be such one. As this is the only "sound editor" I have, to create the "First Age of Empires Modpack" I simply took the file "The Microsoft Sound.wav" from the WINDOWS\MEDIA folder, and it worked perfectly. The Steve's AoE Sound Editor has some interesting features like making all sounds equally loud, etc. Download it from the Telcontar's site and try it. Since it modifies directly SOUNDS.DRS, after finishing your modpack you should extract the modified sounds form SOUNDS.DRS using DRSBUILD.

As for the graphics ... well, as I already said, you can't create or edit them for now, not before the appropriate utility is released by ES. This utility is expected to convert .BMP or some other popular picture (or 3D modeling ?) format to .SLP and .SHP, and vice-versa. So you will probably soon be able to edit the graphics with popular tools and then convert them to .SLP. Till then the only .SLP files you can use are the ones from the standard .DRS files - some of them are really beautiful but not used in the game, so you can make use of them. Please don't try to replace the archer graphics with catapult graphics, this won't make archers shoot better :-)

When your new files are ready, copy all of them into one folder, let's say named NEWFILES. Delete all standard files from it - you don't need to provide any files you have not modified. Then start renaming - if the names of your files don't follow the standard namespace conventions used by DRSBUILD (see above) rename them, or else they can't be put into the .DRS files and tried. After you have renamed your files, try them by executing DRSBUILD with a command-line like (backup your original .DRS files before executing this!):

  DRSBUILD /r \games\MSAoE\data\*.drs newfiles\*.slp newfiles\*.wav
Now start the game and see what you have done. For easier testing, you may need to create a sample scenario that should contain all objects you are customizing.

When you have finished editing and testing, write a short documentation on how your modpack should be installed, or even better an installation script. A standard installation script is provided in the file MINSTALL.BAT, you can ship it along with your files or edit it to create a script that best suites your needs. You can also ship DRSBUILD along with you files, provided that you supply this file also and in unmodified form. You are not required to supply with DRSBUILD any of the files DRSFMT.TXT and DRSFILES.TXT.

Now take all the files you want to provide - documentation, installation scripts, DRSBUILD files, sample scenarios and of course your new graphics and sounds, and zip them. You can zip them without the folder names and write a detailed description of what should be placed where. Or you can zip them with the folder names and require that the user unzips the package into the AoE installation folder preserving the folder structure, so that each file goes to its appropriate place. The recommended folder structure is:

            (new graphics & sounds)
    (DRSUILD files - drsbuild.exe, drsbuild.txt)
    (installation scripts)
With this structure, the user should read the documentation (directly from the archive), unpack the archive into his AoE installation folder, run the installation script & enjoy.


Always backup your original .DRS files before replacing them with the new ones from the modpack! Even if the installation script does so automatically, check what exactly it tries to do before running it, or better copy DATA\*DRS somewhere else and be safe!

The DRSBUILD command-line which actually installs the modpack should be like:

  DRSBUILD /r data\*.drs modpack\my_modpack\*.slp modpack\my_modpack\*.wav
when run from the AoE installation directory. The directory modpack\my_modpack is supposed to contain the new graphics & sounds of the modpack.

The standard installation script MINSTALL.BAT should be always run from the AoE installation directory with one argument - the name of the modpack you wish to install. This name must actually be the name of the folder under MODPACK\ folder where the modpack files reside. For the above example:

  MINSTALL my_modpack
To uninstall the modpack, run the uninstall script (if available) or simply copy your backup-ed original *.DRS files into the DATA folder over the modified ones.


NEVER run DRSBUILD with the "/a" (add/replace) or the "/d" (delete) commands unless you are pretty sure what you are doing! Especially don't try this on the standard .DRS files, or if you do, don't expect the game to work! These commands are dangerous, since their use can lead to .DRS files with additional or missing file types and file identifiers. Only Heaven knows what the game can do if started with such files, but hanging your system is the most probable outcome. Of course you can do this at your own risk and if you find bugs in the work of these commands, your feedback will be highly appreciated.


- "Build" ("/b") command replaced with "Add/replace" ("/a") command.
- "Replace only" ("/r") command added - very useful for installing modpacks.
- "Delete" ("/d") command added.
- Added full wildcards support.
- Added "/o" switch for the output directory.
- Added "/s" switch for silent mode, default mode made "verbose".
- Documentation updated.

Bugs and limitations

For now none available.

Feedback and support

The only important thing one can expect from such an utility like DRSBUILD is: reliability. Or else it will not only make nobody happy, but could really put many people into trouble. So if you suspect the least bug in the work of DRSBUILD, please contact me! Your help will be highly appreciated. I've tested DRSBUILD very carefully, but still I can't guarantee there are no bugs left. I will check carefully every bug-reporting email I receive and fix any bug I find.

I will try to keep up with the game and provide bug-fixes and future upgrades to anyone interested. They will probably be available on the AoE Heaven site at:

and on the Empire of Ages site at:


I would like to thank the following people for supporting and encouraging my work:

Cyrille Artho (telcontar@mordor.ch) for the initial idea, the DRS format specification I started from and for encouraging my work.

Steve Chen (slchen@qte.net), who also participated in the DRS format disclosure and wrote a program for editing the game sounds - it has many interesting features not available in DRSBUILD, but is restricted exclusively to the sounds.

Matt Pritchard (MPritchard@EnsembleStudios.com), the graphics engine and optimization specialist in ES for maintaining the AoE utility developers mailing list and supporting the work of all of us.

Archangel Michael (webmaster@heavenweb.com) for web-mastering the AoE Heaven site and giving me excellent support and feedback.

And of course Microsoft & Ensemble Studios for creating the greatest RTS game of all times, Age of Empires!

Copyright (C) 1997 Stoyan Ratchev. All rights reserved.
Last updated on 30 Nov 1997.

Download it (41 K)

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