Despite being a command-line tool, is prized for its simplicity. The most common command— createcd —requires only a source and a destination. Because it is an open-source utility bundled with the MAME distribution, it is widely accessible and vetted by the community for safety and reliability. For users uncomfortable with the command prompt, the utility’s popularity has birthed numerous "Batch" scripts and graphical user interfaces (GUIs) that allow for bulk processing of entire game collections with a single click. Conclusion
If you are into retro emulation—especially for disc-based consoles like the Sony PlayStation, PlayStation 2, Sega Saturn, or Sega Dreamcast—you have likely encountered massive file sizes that quickly eat up your hard drive space. Fortunately, the retro gaming community has a gold-standard solution for this: the MAME Compressed Hunks of Data (CHD) format.
If you need to return a file to its original format, you can use the Extract CHD to CUE.bat file provided in the Recalbox download pack. Using CHD on Raspberry Pi / RetroArch
Emulators, especially in RetroArch, can read compressed CHD files directly without needing to decompress them first. How to Download chdman.exe
The tool allows you to convert bulky formats like BIN/CUE, ISO, and GDI into the .chd format, which bundles multiple files (like .bin tracks and .cue sheets) into a single, compressed archive without losing any game data. download chdman.exe
chdman.exe (Compressed Hunks of Data manager) is a command-line tool primarily used to compress large disc images—like PS1, PS2, and Dreamcast games—into highly efficient, lossless .chd files. 📥 Where to Download
Right-click the .bat file and select (or open it in Notepad). Paste the following script into the document:
If you have a large library, you don't want to type commands for every game. Most users create a simple Windows Batch file (.bat) in the same folder as chdman.exe:
Many preservation and retro gaming communities on GitHub host standalone copies of chdman.exe bundled with simple batch scripts ( .bat ) to automate the compression process. If you download from GitHub, ensure the repository has high ratings (stars) and positive community feedback to ensure file safety. How to Use chdman.exe to Compress ROMs Despite being a command-line tool, is prized for
: This happens if you double-click the file. You must open a Command Prompt window first, then drag the file in or navigate to the directory.
If you downloaded the Recalbox zip, keep the .bat files in this folder as well. 2. Converting ISO/GDI to CHD
In this guide, you will learn why you need it, where to , and how to use it to optimize your emulation experience. What is chdman.exe?
The file name chdman.exe stands for . It is an official tool created by the MAME team. For users uncomfortable with the command prompt, the
: Tells the program to create a compressed CD image.
For developers, there is a Node.js wrapper that provides pre-compiled binaries: @emmercm/chdman-linux-arm64 . This can be installed via npm using npx chdman to run the binary directly from the command line without a full MAME installation.
: It compresses large disc-based games by up to 50% or more without losing any game data.