PS4 backwards compatibility: Can You Play PS1, PS2, and PS3 Games on PS4?
PlayStation 5 backwards compatibility for PS1, PS2, and PS3 games could be provided by a revamped PS Now service with upscaling capabilities - NotebookCheck.net News
Is The PS3 Backwards Compatible?
Will PS5 Be Backwards Compatible With PS3, PS2, and PS One in Update? - PlayStation LifeStyle
PS5 patent suggests PS3, PS2 and PS1 backwards compatibility is coming | Laptop Mag