This video shows how to softmod a Slim Playstation 2 with Free Memory Card Boot to allow for backups of PS2 games to be stored on and played from a USB hard drive.
PS2 Slim with FMCB (Free Memory Card Boot) -install FMCB to a memory card using multi-install -see modding Fat PS2 video -format USB hard drive as single partition FAT32 disk -plug USB hard drive into slim PS2 and boot it -launch OPL and enable USB to create the filesystem hierarchy -plug the hard drive into a windows machine -games less that 4gb can be copied into \DVD\ as .iso files -games larger than 4gb must be split into multiple files -this is due to FAT32 filesystem restrictions -use USBUtil to copy split isos larger than 4gb https://archive.org/details/USBUtilV2.0FullEnglish_201607 -OPTIONAL: get game art -run the .isos through OPL Manager to download the game artwork -copy the ART folder contents to the ART folder on the usb drive -boot the slim with FMCB memory card and the USB hard drive plugged in