Same as what's on the Motif ES. You can connect a Flash Drive (Thumb Drive), External Hard Drive, etc. to the PSR 1500/3000's TO DEVICE USB connector and then load/transfer the data onto the PSR 1500/3000 and also put Data onto the Thumb Drive, etc., from the PSR 1500/3000. Really cool. Although be aware that not all Devices will work with the PSR 1500/3000. External Devices that use 'Hub Drivers' will not work. You have to get a Device that uses NO Hub Drivers whether it be a Flash Drive (Thumb Drive), External Hard Drive, etc.
Yamaha Genos, Mackie HR824 MKII Studio Monitors, Mackie 1202 VLZ Pro Mixer (made in USA), Cakewalk Sonar Platinum, Shure SM58 vocal mic.