Originally developed by the MAME (Multiple Arcade Machine Emulator) team, the format was designed to compress large hard drive and CD-ROM dumps from arcade machines without losing any data. Because the PlayStation 1 utilizes optical discs, the retro gaming community adapted this compression algorithm specifically for PSX games.

The adoption of CHD for PSX emulation reflects a broader trend in retro gaming: the move toward . In the same way that No‑Intro sets unified cartridge ROM naming and Redump sets standardized optical disc images, CHD provides a compression solution that is both technically superior and practically convenient.

: DuckStation, PCSX ReRarmed, and EPSXe (via plugins).

Save the Notepad file as convert.bat (make sure to change the file type from .txt to All Files when saving) inside the same folder. Step 3: Run the Conversion

While many enthusiasts create their own collections, repositories on sites like Archive.org became popular in 2021 for finding pre-converted CHD-PSX-USA or CHD-PSX-EUR sets 1.2.5, 1.2.4 . Conclusion

To make converting multiple games easy, you can create a simple script to automate the process: Create a new folder on your computer. Place chdman.exe inside that folder. Open and paste the following command:

A single game often consists of one large .bin file and a .cue sheet, or sometimes multiple .bin files, making organization difficult. Why Choose CHD for PSX ROMs in 2021?

A significant bug affected Recalbox 7.2 users in early 2021: CHD files would crash when RetroAchievements was enabled. This was not a universal issue—some frontends like AmberELEC explicitly note that CHD works with achievements—but it did cause headaches for many users at the time. If you experience this, try disabling RetroAchievements or updating to a newer emulator version.

: Unlike the .PBP format (often used for PSP), CHD is lossless . You can perfectly reconstruct the original .bin / .cue files if needed for archival purposes or cataloging.

What are you currently using to play PS1 games?

| Feature | BIN/CUE | PBP (EBOOT) | CHD | |---|---|---|---| | | ✅ | ✅ | ✅ | | Single file per disc | ❌ (multiple .bin files possible) | ✅ | ✅ | | Audio compression | ❌ (raw CD-DA) | ❌ (recompressed, slight quality loss reported) | ✅ (FLAC, lossless) | | Compression ratio | 0% (baseline) | ~40–50% | ~50–65% | | Emulator support in 2021 | Universal | Wide but declining | Growing, soon to be universal | | RetroAchievements support | ✅ | ✅ | ✅ (most cores) | | Multi‑disc handling | M3U playlist | Single PBP can hold multiple discs | M3U playlist or separate CHDs |

By 2021, CHD support became widespread among the most popular PlayStation emulators, meaning you can enjoy your new CHD library on almost any platform.

If you’re looking for a guide on finding CHD ROM sets from 2021, I can’t help with that. But if you clarify your goal—like converting your own discs, setting up an emulator, or verifying file integrity—I’m glad to offer legal, technical assistance.