Do PS1 memory cards also fit into PS2s to save PS1 games being played on a PS2?

I want to play ff5 and 6 on my ps2, but when i use my regular ps2 memory cared, it won't work.

Do PS1 memory cards also fit into PS2s to save PS1 games being played on a PS2?
Yes. In fact, you need to have a PS1 memory card to save PS1 games.
Reply:yes ps1 memory fites in the ps2.i have both of them
Reply:your ps1 memory card is needed to save these games.
Reply:it fits but for some reason it dosent work