Head on ! Tony.
I tried it but could'nt find the right words
Thanx
Sipke
----- Original Message -----
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Monday, March 27, 2000 8:57 PM
Subject: Re: Parallel port hard drives?
<snip>
So, to sum up :
HD disks formated for anything other than 1.2Mbytes (no matter what
drive) -> doesn't work properly.
Bulk-erased DD disks formatted in a 96 tpi drive (including a 1.2M drive
set to use 'normal' disks), but with only 40 cylinders (every alternate
cylinder of such a drive) and then written in such a drive should be
readable in a 48 tpi drive (assuming a correctly set up drive and good
disks, since the read amplitude _is_ lower). They will also (obviously)
be readable in 96tpi drives.
Such disks then written in the 48tpi drive should be readable on both 48
tpi and 96 tpi drives.
Such disks, written on 48 tpi drives (including being formatted on 48 tpi
drives) and then written on a 96 tpi drive (including being reformatted
on such a drive) will _not_ be read reliably on 48 tpi drives.
The is one last point to add to the confusion. Towards the end of the
common use of 5.25" drives, some manufacturers were putting the same
(narrow) heads in both 360K and 1.2Mbyte drives. Such '360K' drives would
write narrow tracks, and would cause no end of problems for people who
took a 360K disk formatted on a 'real' 48tpi drive (wide head), wrote
some files to it with the 'narrow head drive) and then took it back to
a drive with the wider head. Don't ask how I found this out...
-tony