USBD.IRX = The USB-Connection-Driver, which initializes USB and recognizes connected devices.
USBM.IRX; USB_MASS.IRX; USBHDFSD.IRX (newest version of all) = USB-Storage-Devicedriver including support for the filesystem FAT32 (and other FAT-Variants in newest driver, but since only a very few apps use this version, FAT32 is recommented).
PS2 V7/DMS3 V2 (FW:2.4b7); Seagate Baracuda 200GB
PS2 V7/CC1.0 (FW:34 hacked v2 BM:2.1.6); Maxtor DiamondMAX9 PLUS 160GB
PS2 SCPH-30004R; NoMod+NoLaser
3xSony MC 8MB
MAX/Datel 16MB with Boot-CD
Custom FMCB 1.8b+ Beta-Build, my AIO 0.5, Sony&xRhino-Linux