I was looking at a bunch of Tandon TM100-4M floppy drives that I've
had for a (very) long time and saw something that never registered
with me before.
On the underside of the disk release latch (on the faceplate), a
small silver sticker. Most say "100 TPI DSR", but about one in every
4 says "96 TPI DSR". All drives are 100 TPI TM-100-4Ms, BTW as
identified on the body sticker.
Cheers,
Chuck