PS5 Rumored To Have Backwards Compatibility For PS1, PS2, PS3, and PS4
Amazon.com: Power Cord and AV Cable for PS1 PS2 PS3, AC Power Cord and AV Cable Compatible with Playstation 1 2 3, 2 Prong Power Supply & Audio Video RCA AV Cable
Getting an original PS1 Controller to work on the PS3 : r/PS3