If you are a retro gamer, arcade enthusiast, or someone who manages a massive ROM collection, you have likely encountered the (Compressed Hunks of Data) format. Developed by the MAME (Multiple Arcade Machine Emulator) team, CHD is brilliant for saving space—often compressing CD-based games (PS1, Sega CD, Dreamcast, PC Engine CD) by 30-50% without losing data.

chdman extracthd -i "input.chd" -o "output.iso"

@echo off set chdman_path="C:\chdtools\chdman.exe" for %%i in (*.chd) do ( echo Converting %%i to %%~ni.iso ... %chdman_path% extracthd -i "%%i" -o "%%~ni.iso" if errorlevel 1 ( echo FAILED: %%i ) else ( echo SUCCESS: %%~ni.iso ) ) echo All done! pause It processes every CHD in the directory without manual input. It also reports errors immediately. Method B: Linux / macOS (Using parallel for Speed) For power users, this is the “better-est” method. It uses find and parallel to convert multiple CHD files simultaneously, maxing out your CPU.