Instructions
Select "PlayStation Store" under the "PlayStation Network" tab on your PlayStation 3's main menu.
Select "Games" from the menu on the left side of the screen.
Select "PS One Classics" from the menu on the right side of the screen.
Select the PlayStation 1 game you wish to purchase.
Select "Buy Now." At the time of publication, PlayStation 1 games range from $5.99 to $9.99. Once you have purchased the game, it automatically begins downloading to your PlayStation 3's hard drive.
Navigate to the "Game" menu on your PlayStation 3's hard drive once the game has finished downloading.
Highlight the downloaded PlayStation 1 game and press "X" on your controller.
Select "Install" and the downloaded PlayStation 1 game installs itself to your PlayStation 3. To play the game, select it from the list of games in the "Game" menu.