chdman copy -i old.chd -o new.chd This preserves data and upgrades to latest CHD version (if your chdman is modern).
For hard disks (e.g., an old arcade HDD): chd files for mame
for %f in (*.chd) do chdman verify -i "%f" Many arcade games (e.g., Gauntlet Legends , Carnevil , Golden Tee Golf ) use hard disks stored as CHD. chdman copy -i old
dd if=/dev/sdb of=hdimage.img chdman createhd -i hdimage.img -o game.chd | Format | Compression | MAME support | Use case | |--------|-------------|--------------|----------| | CHD | Excellent (zlib/FLAC/zstd) | Native | All MAME disk-based games | | ISO | None (or weak) | Via -cdrom | Simpler CD images | | CUE/BIN | None | Via -cdrom | Redump-style CDs | | CSO | Good | Not native | PSP emulators | | PBP | Good | Not native | PlayStation on PSP | chd files for mame