Ps2 gameshark memo card

[MarthZ]

So I got some ps2 gameshark memory card. But it won't work, am I suppose to use a gameshark disc to use the memory card? Because when i try to play a ps2 game like Kingdom Hearts 2 for example. It says that no ps2 memory card is inserted. I know the memory card ports work because they work when I play a ps1 game with a ps1 memory card. All help is appreciated thank you.