Oops, it's F11 in OS X:
F11 + F1 = Open dialog to insert floppy image in drive 0 F11 + F2 = Open dialog to insert floppy image in drive 1 F11 + F3 = Open dialog to insert floppy image in drive 2 F11 + F4 = Open dialog to insert floppy image in drive 3 F11 + Left Shift + F1 = Eject floppy image in drive 0 F11 + Left Shift + F2 = Eject floppy image in drive 1 F11 + Left Shift + F3 = Eject floppy image in drive 2 F11 + Left Shift + F4 = Eject floppy image in drive 3
Regards, Daniel Pimley