[Discussion] 60FPS patches for PSP games that run at 30FPS

[[Unknown]]

At 0x0881C238, at least in PPSSPP, there's a jal call to sceCtrlReadBufferPositive. This actually points to an import stub, but I'm not sure if the call to the stub is relocated itself.

The issue is, it actually executes that address twice during the processing of a frame. To me, it seems like a bug in the code. Most likely it was only supposed to be called once per frame.

Anyway, a quick-fix is to make it use sceCtrlPeekBufferPositive. The downside is this will add a small amount of input lag, if and only if it gets behind. I didn't experience any briefly testing, so it seemed like a reasonable workaround.

Stubs are 8 bytes in size. The stub immediately after sceCtrlReadBufferPositive happens to be sceCtrlPeekBufferPositive. So moving the jal call by 8 bytes is the trick.

-[Unknown]

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Unfortunately, Narikiri Dungeon X isn't very friendly to the same sort of trick, it'll just go at double speed. Would need to replace 088EF39C with 0, and then figure out where the game's timing is handled, which is probably a lot of work.

-[Unknown]