Parallel port hard drives? - test-drb@ccmp.vtda.org

28 Mar 2000

On Mar 28, 19:14, Tony Duell wrote:

...
  The other thing is that when 96 tpi drives were in
common use, some (lesser)
...
  manufactuerers fitted the narrow head to all drives
(even 48 tpi ones!).
 Or at least some system builders/OEMs did. I have heard rumours that a
 well-known BBC micro supplier sold 40 track, 80 track, and 40/80
 switchable drives. They were actually all the same (80 track, 96 tpi)
 mechanisms. The '40 track' ones had been modified to double-step, and the
 switchable ones had this mod controlled by the switch. 
Canon mechanisms, by any chance?  or Chinon?

...
  Needless to say, these '40 track' drives can
correctly read '40 track'
 disks that have been overwritten by 96 tpi drives (since the head in such
 a drive only 'sees' the narrower 96-tpi-like track anyway), but what they
 can't do is overwrite disks formatted or written on real 48 tpi drives.
 Don't ask how I got to sort this out! 
Yuk!  I can imagine :-)

...
  The other question, of course, is how reliable do you
need it to be.

 For example, the last time I wrote a 40 track disk in an 80 track (96
 tpi) drive was when I wrote a TRS-80 Model 4 boot disk on this linux box
 (which has a 1.2Mbyte 96 tpi drive). I did the following : 
yes, i do things like that quite often.  But not for anything I want to
keep (not the one written in the 80-track drive, anyway) because you never
know if the drive you use next year will be the same...

-- 

Pete						Peter Turnbull
						Dept. of Computer Science
						University of York