FDC is a tool for writing images back to a floppy disc for use with an 8-bit computer

CommandFunction
fd0, fd1Select drive A or B
bbc, bbc80, bbc640ssd, dsd, adf
format0, format1Format drive A or B
write0, write1 [filename]Write selected file to A or B

To use FDC, I would recommend creating a Win 98SE Boot Disk and adding additional CD-ROM drivers if required (SATA, USB, etc)
Create the boot disk, and also a CD containing FDC and all the images that you wish to write to disk
Boot into DOS using the disk and run FDC from the CD. Don't forget to remove the boot disk and insert a fresh floppy for writing!