Re: Best way to make backups of 3.5" disks - copy prog?

[supertimer@aol.com (Supertimer)]

Blake Patterson <blake@blakespot.com> wrote:

>	I actually found some Imation (3M?) "DD 720K DOS" disks at
>MicroWarehouse at something like $5.50 a box.  I just ordered 10 boxes. 
>They had some others that were unformatted (for a buck more / box...?)
>that said "High Density" on the box but right next to it had the letters
>"DS,DD" -- odd.  Anyway -- I want to do the right thing.

http://www.allelec.com/ Alltech Electronics also sells DS/DD
disks in lots of 100.

>	I'm just amazed that these 10-13 year old disks still work.
>Should I be?

Not at all.  Remember, the double density disks used a
STRONGER magenetic field during the recording process.
The coating is also designed for this field.  Thus, the image
sticks better than newer 1.44MB high density disks.

Also, the magnetic media itself is probably still good.  It
is the magnetic image that fades over time.  I bet if you
copy the disks back to themselves to refresh the image,
they'll last another decade.

>I remember paying $49.95 for boxes of 10 Maxell 3.5" disks back
>when I had an Amiga 1000.  Seems like the quality was higher then as
>well.  I mean, I go ahead and take a 3.5" disk out of the supply closet
>at work and write some HD data to it (PC) and need to worry if the
>motion of ejecting the disk, moving through the electromagnetic field of
>the earth, is going to erase the data that was just written.  Is it me
>or have 3.5" disks just REALLY gotten HORRIBLY unreliable??  (Actually,
>the first disk out of the box of 100 Sony HD disks I just got for $25,
>when put in the GS caused a horrible noise--turns out the disk was
>jammed and would not rotate.  Amazing.)

There's bound to be slightly more failures for high
density disks.  I've noticed it even on my IIGS,
which I switched over to a SuperDrive a long time
ago.  Same for my Windows PC.  It has to do with
using a weaker magnetic field to store more data
on the same surface area.