"CHD PSX ROMs 2021" likely refers to collections or releases from around 2021 that provide PlayStation (PS1) disc images converted into the CHD format for use with emulators that support CHD (for example, some builds of RetroArch’s Beetle PSX HW core or standalone MAME/MESS builds that support PlayStation). Below is an article-style summary covering what CHD PSX ROMs are, why people use them, compatibility, how to use them, legal and safety considerations, and alternatives.
If you have legal BIN/CUE rips (e.g., from your own discs using ImgBurn), you can convert them using the utility (part of MAME). Here’s the 2021-era command-line process: chd psx roms 2021
Before the widespread adoption of CHD, PSX ROMs were typically stored as or ISO files. CHD files - RetroPie Docs "CHD PSX ROMs 2021" likely refers to collections
What are CHD PSX ROMs?
No special “2021” tools are needed—the same chdman version works today. than original BIN/CUE files because they use lossless
than original BIN/CUE files because they use lossless compression that removes "zero-fill" data. Single-File Simplicity:
The move to CHD in 2021 was effectively a "modernization" of the PSX scene. It moved the ecosystem away from the fragmented file structures of the late 90s and early 2000s toward a modern standard optimized for digital preservation and ease of use. While purists still archive the original .bin/.cue sets for long-term preservation, CHD remains the practical standard for playing PSX games on modern hardware and software today.