[rescue] 5.25" floppy on modern PC

[gsm at mendelson.com]

On Sat, Aug 15, 2009 at 03:35:02PM -0400, Weiss Andrew wrote:
> So why use a 360K?  Why not a 1.2?  They can read and write 360K  
> floppies just fine.  There are also those fun TEAC drives that have one 
> 5.25 and one 3.5 drive in one 5.25" bay.

It depends upon the original drive that wrote the floppies. Drives from
before the PC/AT era read and wrote wider tracks. Because people had trouble
reading 360k disks written on 720k (80 track, "low density") drives and AT 
drives, both of which wrote narrower tracks, the later 360k drives were made 
with the narrower heads. I'm sure there was also a cost saving having only
one type of head in stock.

If you are trying to read 360k disks written on 720k or 1.2m drives, you
would be better off with the narrow head AT drives, if you are trying to read
disks written on 360k full track drives, you would be better off using 360k
full track drives. 

There are also problems reading disks written at  300 RPM (PC) in 360 RPM 
(AT) drives, but I don't know what they are. 

I have no idea of how to tell, but my guess is that the full height drives are
wide track. 

Geoff.

-- 
Geoffrey S. Mendelson, Jerusalem, Israel gsm at mendelson.com  N3OWJ/4X1GM