Spludlow MAME - CHD (Compressed Hunks of Data)

MAME: 0.271 - Released: 2024-10-30T15:59:16 - Machines: 47358 - rom: 354314 - disk: 1336 - Lists: 717 - Software: 138541 - rom: 234702 - disk: 11183

Certain MAME Machines require a CHD (Compressed Hunks of Data) file to run you will be given an error message if not present. Machines from around the 1990s onwards started using hard disks or optical disks as well as ROMs to hold greater amounts of data.

CHD files are containers that hold a header and the compressed payload of the disk image, unlike the ROMs which are the RAW uncompressed image of the original ROM.

This means that the SHA1 hash of a CHD file will not mean anything. To get the SHA1 that matches the sha1 in the disk table of the MAME database you can use the following command from the MAME directory (SHA1 is what you’re looking for):

    chdman.exe info -i "filename.chd"

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