100TPI floppy disk drives

[Chuck Guzis]

On 9 Oct 2007 at 20:21, Andrew Lynch wrote:

> Does anyone have some 100TPI floppy disk drives they would be willing to
> sell?  I think I will need at least two or three drives total so even if you
> have only a single drive you can part with, I would appreciate an offer.

Insofar as I'm aware, Micropolis originated the 100 tpi format and 
there were few followers.  I recall that Micropolis even marketed 
their own 2-drive box for a time.  Not every old Micropolis drive you 
see, however, will be 100 tpi.  They also made 96 and 48 tpi drives.

Tandon TM-100-3M (Single sided) TM-100-4M (Double sided)and a couple 
of MPI/CDC drives was about the extent of the cloning, as far as I 
know.  Some of the old CBM Pet drive boxes (8050/8250?) used 
Micropolis drives; Vector was about the last one out of the bath with 
their Tandon TM-100-4Ms.  Bottom line is that they were made by only 
a handful of manufacturers (if three is a handful), were never 
common, and were pretty much history by 1980--and a fair number were 
single-sided.

Cheers,
Chuck