Keir Fraser’s Greaseweazle is a project for versatile floppy drive control over USB. By extracting the raw flux transitions from a drive, any diskette format can be captured and analyzed - PC, Amiga, Amstrad, PDP-11, many older electronic musical instruments, and industrial equipment. The Greaseweazle also supports writing to floppy disks. The design is fully open and comes with no license encumberment.
A companion code library, Disk-Utilities, converts between flux images and multiple, standardized floppy disk image file formats. These can then be used in hardware floppy emulators, like the Gotek or FlashFloppy, or as disk images in hundreds of pure software emulators.
Very inexpensive! $30us!