It would be interesting to know how Outbound's solution worked with the IWM driver in the Mac ROMs. (Outbounds used ROMs pulled from genuine Macs, didn't they?) Did the circuit board emulate the IWM, did they patch the software somehow, or what?
It's interesting to contrast Apple's Macintosh drives with Commodore GCR drives; both systems cram a variable amount of data onto different tracks on the floppy disk. The difference is that Apple did it by varying the spindle speed, while Commodores do it by changing the data rate. There is another thread on this board where someone says that essentially the Outbound uses the magic on that board to allow a fixed-speed floppy drive to read and write Mac floppies the Commodore way, and that makes perfect sense.
(Again, I'm just sort of curious if it was software-transparent or involved a patch. They must have already been patching the Mac ROM to use the larger 640x400 screen...)
Apple's floppy drives are really stupidly overly-engineered. Commodore's variable-rate floppy drives predated the Mac by over five years, and it's a better solution; the variable-spindle speed thing was invented for the Twiggy and it's the major reason that device failed. It takes several rotations to change the spindle speed and get it stable (there's this thing called "inertia"), and the problems get worse the physically larger the device. Apple is lucky the Sony mechanism worked as well as it did once they were done with it.