Because Commodore's native disk format is GCR, it may be difficult or impossible to use another platform to write a disk readable by the Commodore. One possible exception would be to use one of the newer drives such as the 1571 or 1581 that is able to read MFM disk formats, but I'm not aware of any software that does this. Another possibility would be to key in a simple terminal emulator written in BASIC, that allows file transfers. Likewise, I am not aware of any such program. One solution is to build a cable that allows a Commodore floppy drive to be connected to an IBM PC compatible's parallel port, and a program called X1541 that allows reading and writing of data on Commodore disks (a link to this software is coming soon).