This hack was developed in order to disable the floppy drive(s) on a Macintosh. I developed this in order to correct a problem that I ran into with my old SE.
This system extension requires that the MountImage CDEV be loaded BEFORE the extension, so you would have to put the MountImage CDEV in the Extensions folder, followed by this one.
The hacks work by finding the MountImage device driver (refnumber=0xFFE0), recording the pointer to that driver, and putting into the driver unit table when it finds the floppy drives (refnumber=0xFFFB).
The downside of this hack is that it's not clean, it's raw, it requires another hack program (MountImage), and it "locks" the disk into place if the user sticks a disk in the drive. Oh well, it gets the job done.
If you want to make changes to this program, add to it, enhance, etc, etc, please do so, and please email me the source!
PS: I built two versions of the program, one as an application, one as an extension. Both do exactly the same, but the app is safter, since you can do it anytime and reboot to fix...