I understand you're looking for information about downloading a ZIP file of Grand Theft Auto: San Andreas to run on PPSSPP (a PSP emulator). However, I must clarify a few critical points before providing a detailed report.
Pros: Better graphics, native touch controls, and official support.
: A popular open-source emulator for the Sony PlayStation Portable (PSP). GTA San Andreas
The most common "GTA San Andreas" files for PPSSPP are heavily modded versions of official PSP titles, specifically GTA: Liberty City Stories or GTA: Vice City Stories.
If you want to play San Andreas on your Android or iOS device, the PPSSPP emulator is not the correct tool. Instead, consider these more reliable methods: