Sony released its hand-held video game console,PlayStation Portable (better known as the PSP) on March 24, 2005 in North America. PSP owners can play a variety of games and movies made specially for the PSP as well as emulator games from older versions of PlayStation. However, emulators do not take up the whole PSP screen because the games were designed for a different screen size and ratio. PSP owners who play PSX (emulator games), can adjust their screen display to deal with this issue.
Press the "Home" button on your PSP.
Scroll down to locate and select "Settings."
Choose one of the following screen sizes to adjust the appearance of your game:
"Fullscreen" changes the display to full screen, similar to your television. This adds small black borders to the top and bottom of the screen so that the emulator fits the 16x9 ratio.
"Original" is the default display for PlayStation games and will display the game at 320 x 240px.
"Normal" stretches (less than "zoom") and smooths out the display.
"Zoom" stretches the display so that the width is equal to the width of the screen size.
The "Zoom" option may only exist for the 3.10 PlayStation (PS1) emulator.
Changing the screen size can cause distortion to your game's appearance.