Abstract The preservation of optical media, particularly for video game emulation, has led to the development of various file formats balancing compression, integrity, and access speed. While ZIP archives have long served as a universal container for compressing disc images (ISO, BIN/CUE), the CHD (Compressed Hunks of Data) format, originally developed for MAME (Multiple Arcade Machine Emulator), offers significant advantages. This paper examines the methodology, tools, and rationale behind converting a ZIP archive containing a disc image into a CHD file, focusing on compression ratios, performance, and structural integrity.
If you ever need to revert (for a legacy emulator or disc burning), you can extract a CHD back to BIN/CUE or ISO:
chdman extractcd -i game.chd -o game.cue
Then re-zip the resulting .cue and .bin files using 7-Zip. Convert Zip To Chd
Let’s convert a real example: Final Fantasy VII (USA).zip for the PlayStation 1.
Not all emulators support CHD. Here is the current compatibility list: Abstract The preservation of optical media, particularly for
| Emulator | CHD Support | Best For | | :--- | :--- | :--- | | MAME | Native (created it) | Arcade, home computers | | RetroArch (Beetle PSX/HW) | Full | PlayStation 1 | | DuckStation | Full | PlayStation 1 (Recommended) | | PCSX2 (nightly) | Partial / Experimental | PlayStation 2 | | Redream | Full | Dreamcast | | Genesis Plus GX | Full | Sega CD | | Ares | Full | Multiple disc systems | | Dolphin | No (use GCZ or RVZ) | GameCube/Wii |
Note for RetroArch users: CHD files are treated as regular disc images. Use Load Content → select the .chd file directly. Then re-zip the resulting
Converting files from ZIP to CHD is a common process for retro gaming enthusiasts. The CHD (Compressed Hunks of Data) format is widely used for CD-based game systems (like PlayStation, Sega CD, and Dreamcast) in emulators such as MAME, RetroArch, and Dolphin.