Many users confuse the game .bin with the file. The PS1 BIOS (usually named scph1001.bin or scph5501.bin ) is a 512KB file containing Sony's proprietary boot code. You cannot play any PS1 game without it.
If you’ve ventured into the world of PlayStation 1 emulation, you’ve likely encountered a file simply named ps1 rom.bin . While the name might suggest it’s a game ROM, that’s a common misconception. Let’s clear things up.
For archival, .bin/.cue is the gold standard. For everyday use on a Steam Deck or phone, .chd is superior.