Instructions
Scroll to the "Game" tab in the Sony PS3 XMB menu. This is the system menu that appears when the console is first turned on or the "PS" button on the controller is pressed.
Click "Memory Card Utility (PS/PS2)" under the "Game" tab.
Click "New Internal Memory Card."
Click "Internal Memory Card (PS)" or "Internal Memory Card (PS2)." The memory card must match the format of the older game being played. You cannot save a PS2 game to the PS internal memory card or a PS game to the PS2 internal memory card.
Enter a name for the memory card into the prompt. The first internal memory card created on the console is automatically assigned to "Slot 1." This is equivalent to plugging a memory card into the first slot on a PS1 or PS2 console. The PS3 will emulate a PS1 or PS2 console in play, which includes emulating the information from the internal memory cards.
Insert the PS1 or PS2 game disc into the disc drive of the PlayStation 3. The game will automatically start. The game will be able to save to the memory card like it would on the original console.