Copyright Dr Alan Solomon, 1986-1995

Peter Norton has just brought out version five
of the famous Norton Utilities. As everyone knows, with the old Norton
you could UnErase a file (similar to UnDelete; 15 from S & S on
02403 4201). Now with version five, you can not only UnErase files
from floppy or hard disk, you can even UnFormat a disk. This is
likely to prove a lifesaver for all those people that accidently
format their hard disks, or even those who accidently format a floppy.

The only problem is that the process takes a long time. To UnFormat
a disk, the disk drive has to read each track over and over again.
Magnetic traces of what was on the track before formatting still remain,
and by reading the track 100 times, and averaging the resultant signal,
it is eventually possible to reconstitute the data on that sector. If the
program finds that the data is still ambiguous, it asks you if it should
give the disk a further 200 reads, then 400, and so on.

Before I tried this utility out on my hard disk, I carefully backed it
up, in case UnFormat was unable to recover all of it. Then I did
something that took a lot of willpower - I formatted my hard disk.
When I ran UnFormat, it scanned the disk once, and informed me that the disk
had just been formatted, then it set to work. A display on the screen kept
me informed of progress as it worked its way down from track 0 to track 305.

After about an hour, UnFormat reported that it had been able to recover
about half the formatted sectors, and that there were 15 complete
files available (originally there had been about 1000). I chose the
option that told it to continue recovering until interrupted, and went to bed.
Next day, UnFormat had been running for some 12 hours when I stopped it.
It reported that it had recovered 94% of the sectors; 723 complete
files. At this point, I stopped it. If I had let it run for a couple of days,
I think it might have recovered rather more; even the 94% recovery rate
was pretty impressive.

If you don't already have the Norton Utilities, get them. If you do, get
the upgrade to version five. One day, you'll accidently format your hard disk,
and be glad you had UnFormat.  Version five will be on general release
on 1st April 1986.