PS1 games on PS4: Which PlayStation 1 games can you play on PlayStation 4?
HOW TO PLAY PS3/PS2/PS1 GAMES ON PS4 | BACKWARDS COMPATIBLE PS5? - YouTube
PlayStation 4 and PSVita Releases: PCSX-R port for the PS4 has been released allowing you to emulate PS1 games and ElevenMPV 2.1.0 released with many fixes! - Wololo.net
PS5 Backwards Compatibility: Can You Play PS3, PS2, and PS1 Games on PlayStation 5? | Push Square
How to play PlayStation 1 games on PlayStation 4 - YouTube
Can you play PlayStation 1 games on a Playstation 4? - Quora
How to Play PlayStation 1 & 2 Games on PS4 - pokemonwe.com
EP 7) How to Run PS1 & PS2 Games on a Jailbroken PS4 - YouTube