Ever wondered how you could reduce the size of your PlayStation ROM collection globbing your hard drive space and preventing you from hoarding the libraries of other, worse better consoles?
Learnt about the wonders of the CHD file format, but tried to search how to convert your poor BIN/CUE files to this amazing format only to end up on a sea of Windows-only tutorials?

Well, you don't have to wait anymore, because with the secrets I learned by converting some ROMs I had on my PaRappa the Rapper game archive you can now convert your games to CHD and immensely reduce the size of your collection while preserving the quality of the original discs, allowing you to store even more VIDYA!

While this tutorial is specifically focused on PlayStation games, it can also be applied to PlayStation 2 titles, and ostensibly to Sega Dreamcast ones as well.

The tool that will allow you to make all of this possible is called chdman. It is developed by MAME, and like its title, it allows you to manage CHD files. In most *nix systems, it should be included with the MAME package, so it's time to CTRL+ALT+T that terminal and type in the following:

However, there are two major distros where installing the mame package does NOT install chdman as well - Debian (and it's non-Ubuntu derivatives) and Arch. In these two distros, you want to install mame-tools instead.

After this step, it's time to actually convert your files.
Enter the directory where your ROMs are located, whether through cd or by right clicking on your desktop enviroment's file manager and clicking on "Open terminal here" and follow this command.

Replace 'PaRappa The Rapper (Japan)' for the filename of whatever game you're planning to convert in both the input (-i) and output (-o) parts of the command, and make sure to pick the .cue file!
Once you have this typed, chdman should be hard at work, compressing your ISO to anywhere from 2/3rds to less than 10% of its original size depending on the game! Now just plop in your emulator, load up that sexy CHD file and enjoy!