At one point, the 100 TPI was nominally TM 100-4M.  I'm guessing that the
'M' derived from "Micropolis", the originator of the 100 TPI drives that
the -4M would be suitable for replacing.
But I have a drive that was sold new as a -4M on which I can find no trace
of an 'M'.
Can we assume that a -3 wopuld be a 96TPI SS?
--
Grumpy Ol' Fred        cisin(a)xenosoft.com
On Mon, 18 Oct 1999, Richard Erlacher wrote:
  I've got a -4A with a sticker on the door latch
which says 96tpi.  Do these
 also come in 100?
 Dick
 -----Original Message-----
 From: Don Maslin <donm(a)cts.com>
 >There should be a dash number associated with the TM 100, Bill.  IIRC,
 >-1A is SS 48tpi, -2A is DS 48 tpi, and 4A is either 96 tpi or 100 tpi.