While playing, press the button (or PS button on Vita). Go to "Settings" (the briefcase icon). Here you can:

For survival horror enthusiasts, the original Silent Hill remains a touchstone of psychological terror. Released in 1999 on the original PlayStation, Konami’s masterpiece broke the mold established by Resident Evil , trading jump scares for a suffocating atmosphere of dread, rust, and radio static. However, as hardware ages and physical discs become prone to scratching and bit-rot, playing the original game on native hardware is becoming increasingly difficult.

To understand why Silent Hill 1 runs so well on the PSP, one must understand what an "Eboot" actually is.