In this video, I show you how you can easily copy files between two disk drives, using the Uni-Copy program. Uni-Copy was published on the 1541 Demo Disk, which was originally shipped with most 1541 Floppy Disk drives.
In this demo, I already have two floppy disk drives connected to my C64; one configured as Drive #8 and the other as Drive #9. However, Uni-Copy does have the ability to configure your floppy drives (using software), so one of them is identified as Drive #9, if you haven't already done so.