The fifth generation era in video gaming gave us many new advances in gaming. Chief of which, optical disc technology. The use of CDs allowed for greater data storage which yielded more sophisticated and elaborate games. One of the few drawbacks to CDs was the inability to save games. Unlike their cartridge counter parts, there is no room for a battery on a CDrom.
Enter the memory card. Though now all but phased out only 2 generations later, those of us that still play the classics need to deal with them.
Sadly, Sony didn’t make it possible to save PS1 game data to PS2 cards. Also, 3rd party cards do not work on the PS2 slim. Therefore, used official PS1 cards demand a premium. Backward compatible PS3s do not require memory card to play either PS1 and PS2 games, however, an adaptor is needed ($14.99 USD) to upload any previously saved data from existing cards.
Here is a break down of Playstation memory cards and their compatibility based on console.
Personally, I just have a PSOne and a PS2 slim hooked up. I wont need pricey Sony made PS1 cards that way.
(1) IGN PS3 Memory Card Adaptor Hands-on: 11/28/2006 http://ps3.ign.com/articles/747/747933p1.html