Use the tool mentioned above to import that .psu into your PCSX2 directory.
The single best way to improve your PCSX2 saving experience is to switch from the traditional .ps2 "Mcd" files to the Folder (Folder Memory Card) system. memory card save file for pcsx2 ps2 better
If you have hundreds of games, one folder or file can get cluttered. Use the tool mentioned above to import that
While modern PCSX2 versions handle this well, manually ensuring the card isn't "writing" when you shut down the app prevents file header errors. Organize Your Library with Multiple Cards While modern PCSX2 versions handle this well, manually
The PlayStation 2 era was the golden age of gaming, but dealing with limited 8MB memory cards was always a struggle. When using PCSX2, the premier PS2 emulator, you have the power to move beyond those physical limitations. If you are looking to make your memory card save files better, more reliable, and easier to manage, this guide covers everything from folder-based saving to importing 100% completion files. Switch to Folder-Based Memory Cards