In the world of PS2 emulation, "Mcd001.ps2" and "Mcd002.ps2" represent the virtual equivalents of the physical memory cards you would insert into Slot 1 and Slot 2 of a real console.
Most "Mcd002.ps2 download" links online are either unnecessary or potentially unsafe. You can easily create a fresh, clean memory card file directly within PCSX2 : Mcd002.ps2 File Download
These files use the .ps2 extension , which is a raw disk image of a PS2 memory card. In the world of PS2 emulation, "Mcd001