Thank you for the links. I had seen the Miniscribe 8425 photos some time ago, but that drive doesn't look like the drive used in my Hyperdrive Mac. Note how flat the top casing is on the 8425. Now note two major differences with my Hyperdrive mechanism: (1) it's tapered in sections on the top part and (2) it has a round orange plastic insert on the top as well. Both of these differences can clearly be seen in this photo:




Now compare that with the perfectly flat top of the 8425:

http://www.harddrives-usa.com/MINISCRIBE-8425-MFM-3.5-IN-HH-hard-drive-pr-5376.html

Another difference. If you compare my Hyperdrive photos with the 8425, you can see that the power connector on back is on opposite sides.

So I think the doctor truly is still "out" on this subject.