What Do You Know About CHD Files & How Can You Use Them?


Are you looking for CHD files? If you are into retro gaming, you might have come across files with the extension of “.chd”. In most situations, those files have some things quite common: they have cryptic names, are quite large, and don’t look essential in anything.

CHD Files

CHD files are arcade game disk pictures used by MAME. It explains why they are so large in file size. Currently, they become quite popular among lots of emulators that use large ROMs. Also, it includes emulators like some of the PlayStation Libretro cores in Retroarch and, by add-ons, all the amazing emulation-oriented distributions for the Raspberry Pi series of microcomputers.

If your CHDs are MAME ROMs, they saved in folders with the same name at the bottom of MAME’s main ROM folder.

If they are game backups for the real PlayStation or console that used uses optical discs, they should, in some situations, put directly in the emulator’s ROM subdirectory.

During console emulators, CHD files contain the whole game, so you can “open them” in the emulator and begin playing. In MAME, though they are part of the game due to MAME emulates arcade machines.

Besides gaming consoles, arcade games usually had dedicated software or hardware that differed from game to game. The software part is typically saved in ROM chips. At some point, using ROM chips quite costly and games getting bigger with more impressive visuals, their manufacturers begin using CDs or hard disk drives. They used them to save the most substantial assets of games – audio, graphics, music, animations – while keeping the game smaller “core parts” on the ROM chips.


CHDs are usually useless on their own with MAME. You want the actual ROM files that accompany them to use them. However, the CHD files contain the game’s assets but not the game itself. You also find the ROMs that move with your particular CHD file and any additional files related to the hardware on which the game ran. For that, as it remains a legal gray area, we can only say that Google is your friend.

Put those ROMs in MAME’s ROM subdirectory, put your CHDs in the same spot but sub-directories using their own name, and then try executing the ROM with MAME. If you can’t use a command-line but a GUI-based variant of MAME, you probably want to execute a scan/audit of your ROMs first.

CHD Files’ Contents

The amazing tool for working with CHD files comes with their source, from MAME itself. It’s known as chdman. However, it depends on your MAME set up, it’s either installed or bring it on board with the command:

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