Sparky, the drives usually come pre-formatted. However, some have their own operating system, which must be removed on the PC before the Tyros can read or write to them. After removing the drive OS, then format the drive using the Tyros.
If you are using the original OS of the Tyros and have not updated, the root directory of the USB can hold 250 files or folders and each folder can hold 250 files, at least that's what I remember from way back when the T2 first became available. There was something in the user manual that provided that information.
Good luck,
Gary
_________________________
PSR-S950, TC Helicon Harmony-M, Digitech VR, Samson Q7, Sennheiser E855, Custom Console, and lots of other silly stuff!
K+E=W (Knowledge Plus Experience = Wisdom.)