New update: adds support for the Mac Classic (and probably a bunch of others with similar ROM)

http://www.bigmessowires.com/floppy-emu-1.0E-F4.zip

Known compatible Macs:

512K

512Ke

Plus

SE 800K

Classic

I don't know of any *incompatible* Macs, but these are the only ones that have been tested so far.