I suppose this is a duplicate of #12841. PPSSPP supports rewind, but it seems to be issues with the libretro API that make things not work.

Libretro was, unfortunately, designed with weaker systems involved and doesn't really support things like multithreading being used by the emulator. Since the PSP is much more powerful (10x Mhz, 16x RAM, etc.) than systems like the PS1, it's more necessary to use modern software techniques for good speed and so it causes problems that libretro was designed in such an antiquated way.

Anyway, I'm going to close this as there's already an issue about rewind working and another issue about the various crashes you get only with libretro.

-[Unknown]

I agree that libretro its what it is, and the PSP is much more powerful than a PS1 obviously. I reviewed the already implemented "rewind" feature on PPSSPP, but its not much what I expected. Its more like an auto-snapshot than a rewind thing. Well, thanks for answering.

That's pretty much the same way rewind works in any other emulators, the primary difference is amount of memory and complexity which makes something like PSP rewind much more limited in how it can work and not used by most people due to crazy hardware requirements to be smooth despite tons of optimizations.

Yeah I see it's not worth it enough to implement it yet.