(Continued from previous message)

drive. Use the proper DOS FORMAT command parameter (see your
DOS manual) so it is formatted in DD mode, i.e. at a reduced write
current to match DD requirements and at 40 tracks instead of 80.
This way you have compatibility between the two drives. Remember,
though, that if the disk has been previously formatted or
written on with a DD drive you still have the excess portions of
the DD track to give possible problems. Fortunately, you are
virtually certain to get many bad sectors or total failure if you try to
format a DD floppy as a HD floppy.

########################################################################

3 " floppies and drives were better designed for compatibility between
DD and HD floppies by virtue of the media sensor hole in the HD
floppy. The number of tracks and track width stayed the same; only the
data density was doubled and the coercivity increased by 100 oersteds.
When a HD drive senses a DD disk (720 KB) by the lack of a hole in
the corner opposite the file protect hole, it reduces the write current so
as to provide the proper write current for the reduced coercivity of the
DD disk. Also this is the reason one should never try to scrimp and
make a HD disk out of a DD disk by drilling a hole in the corner to
match that of the HD disks. When the DD disk is formatted or written
at HD write current strength it may work OK for a while but sooner of
later some data bits will blend together causing data loss.
WARNING! Owners of IBM PS2s or other PCs with true IBM PS2
type 3 ® HD drives BEWARE! IBM PS2 type HD floppy drives do
not sense nor use the 1.44 HD indicator hole - these drives will try to
format ANY floppy inserted in HD mode unless the proper Format
command parameter in given with the format command!
Unfortunately some DD floppies will format as HD.  They will
usually experience a data loss sometime in the future!

#####################################################################3

Considering the falling prices of floppies and drives and the tremendous
increase in capacity, it makes good sense to convert to HD drives and
disks as much as possible. Just think: A full 30 MB hard drive backup
on 360 KB floppies can take over 70 floppies and up to 45 or more
minutes. By using 1.2 MB floppies you cut the floppies to about 25 and
the time to about 25 minutes. 3 ® disks provide a somewhat greater time
and quantity savings.

Things will be even better when the new 2.4 MB  and 2.88 MB disks
and drives hit the market! Lets hope they are as backward compatible
with the 1.2s and the 1.44s as the current 1.44s are with 720s. Just
think, with 2.88 MB disks one could backup a 30 MB hard drive with
maybe 11 disks and in 10-15 minutes. These backup times and disk
quantity estimates are based on using Fullback + v 1.12. Three cheers
for progress.

One other fact: Airport X-ray security checks WILL NOT affect the
data on your floppies.


Jay
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 þ OLXWin 1.00a þ An appeaser feeds the crocodile, hoping to be eaten last.