Playstation (commonly known as PSX or PS1) was a 32-bit console in the fifth generation of game consoles along with Nintendo 64. Although it only had 32-bit graphics, Playstation was a strong adversary to N64 and released many great titles. PSX Emulators do require a BIOS files to operate, please download it here. After you've specified the BIOS and set it up correctly, you can download some Playstation ROMs.
If you need additional help, read our getting started guide.