[comp.sys.ibm.pc] How to write 360K disks in a 1.2MB drive

kevin@calvin.EE.CORNELL.EDU (Kevin Tubbs) (06/29/88)

In article <8362@bellcore.bellcore.com> jef@djinn.UUCP (Jonathan E. Flamm) writes:
>...Is there
>software available that will RELIABLY write 360K diskettes on 1.2MB drives
>so they can be reliable read on 360K drives.

I have had excellent success by "erasing" (with a magnet or bulk eraser)
the diskette prior to formatting (in 360K format) in the 1.2MB drive.  The
major problem seems to be when a diskette has already been formatted in
360K format in a 360K drive, and then formatted as a 360K in a 1.2MB drive.
This leaves behind remnants of the original 360K tracks, which the 1.2MB
drive doesn't wipe out.

You could also use a blank-out-of-the-box diskette, if you have no way
to erase a used one.

-- 
Kevin Tubbs, 5152 Upson, Cornell University, Ithaca NY, 14853  (607) 255-8703
kevin@calvin.ee.cornell.edu  {uunet,rochester}!cornell!calvin!kevin

mintz@hpindda.HP.COM (Ken Mintz) (07/07/88)

> If you buy a copy of the COPYiiPC program, it includes a utility called
> BULKERAS.  This is a program that will completely blank out a disk.  It
> works with 1.2M drives as well...it's good insurance before you format your
> 360K disks.

  This leaves me thoroughly confused (again).  I understood that the 360K-
  disk-on-1.2M-drive problem was a physical limitation, namely that the 1.2M
  heads were narrower than the 360K drives and, thus, failed to overwrite all
  the magnetic fields.  (I suspect subsequent read success on a 360K drive
  would depend on the sensitivity of the read head.)

  Degaussing (bulk erasing) works only because it affects the entire magnetic
  surface, not just the track under the head.  But COPYiiPC would have to use
  the write heads of the drive to "erase" the disk.  Thus, I don't see how this
  could be 100% reliable.

  Is there something wrong with my understanding?

  BTW, since you mentioned COPYiiPC:  can it "copy" a 1.2M disk if all you 
  have is one floppy drive and a hard drive -- that is, without asking you
  to constantly switch floppies?  The ideal implementation would build a disk
  image in memory (if there's enough) or on the hard disk, then ask you to
  switch floppies.  Does it work that way?

Ken Mintz

mvolo@ecsvax.uncecs.edu (Michael R. Volow) (07/08/88)

In article <4330094@hpindda.HP.COM>, mintz@hpindda.HP.COM (Ken Mintz) writes:
> > If you buy a copy of the COPYiiPC program, it includes a utility called
> > BULKERAS.  This is a program that will completely blank out a disk.  It
> > works with 1.2M drives as well...it's good insurance before you format your
> > 360K disks.
>   BTW, since you mentioned COPYiiPC:  can it "copy" a 1.2M disk if all you 
>   have is one floppy drive and a hard drive -- that is, without asking you
>   to constantly switch floppies?  The ideal implementation would build a disk


When we have tried to copy files from a 360K drive to a 1.2 meg drive
it didn't work, and we got a message something like "adjusting drive
speed".  I have not tried the bulkerase feature.

In the back of PC Mag there used to be a utility called, I believe,
CPYAT2PC, which was supposed to let 1.2 M drives write to diskettes
formatted in 360k drives, but I've never seen it used.


Michael R. Volow                   919 286 0411
Dept. of Psychiatry                mvolo@ecsvax.UUCP
Durham Vet Admin Medical Center
Durham, N.C. 27712

mintz@hpindda.HP.COM (Ken Mintz) (07/10/88)

# SUMMARY OF RESPONSES TO MY QUERY:
> BTW, since you mentioned COPYiiPC:  can it "copy" a 1.2M disk if all you 
> have is one floppy drive and a hard drive -- that is, without asking you
> to constantly switch floppies?  The ideal implementation would build a disk
> image in memory (if there's enough) or on the hard disk, then ask you to
> switch floppies.  Does it work that way?

  Several people sent email confirming that COPYiiPC will work adequately in
  a single-floppy environment.  Apparently, DISKCOPY has also been improved
  to make full use of available memory.  Thus, both try to minimze to disk
  switching.  However, it also appears that neither will buffer to the hard
  disk, if available, to avoid switching disks more than once.

  One person indicated that COPYiiPC does  n o t  work on 1.2M floppies.
  However, one other person specifically indicated it would.  It doesn't really
  matter to me:  I misspoke (miswrote?).  Since no software is distributed on
  HDDS disks, I was interested only in copying 360K disks on a 1.2M drive.

  Thanks for all the responses.

Ken Mintz