[Coco] Disk Cleanup

[Robert Gault]

Bill Pierce wrote:
>
> Ok guys, got a good one for ya...
> snip
> And can a disk be removed from it's plastic case and put in a temporary case for a one time read?
>
> Bill Pierce
> ooogalapasooo at aol.com

There are two criteria important for reading disks of the 5 1/4" type. 1) Is the 
magnetic media intact and still magnetized. 2) Does the disk freely turn inside 
the case?

Clearly if the disk has become demagnetized, the data is gone. Disks don't last 
forever but aside from that, heating or abrading the surface will cause loss of 
magnetic info.
Heating frequently happens when disks are squashed together and the edges of the 
case get flattened. When you try to read such a disk, the friction of the liner 
on the magnetic media can and does kill the disk.
If there is dirt of any kind on the surface of the disk, the magnetic media can 
be scraped off as the disk rotates. You could also damage your drive's heads.

I have been able to pop the heat seals on 5 1/4" cases, remove the disk, spread 
the edges, reinsert the disk, and read it. Spreading the edges reverses the 
effects of squashing and you can see that the disk spins faster.
Break only the seals on the center edge, the side away from the head window. 
Bend that back to pull out the magnetic media. Handle the magnetic media as 
little as possible. Make absolutely certain not to flip the magnetic media 
over!! It MUST go back into the case having the same orientation as it came out!!

If most of your disks are contaminated, find at least one that is clean and use 
that as a temporary case for all the other magnetic media. I don't know of a 
safe solvent for washing a disk but you could make a test with a known good 
disk. Try water to rinse off any dirt or mud. Blot and air dry the disk and 
insert it into a case. If it will read/write, you are set.

You can read/write a disk with the center edge popped as often as you like. You 
don't need to glue or tape the edge in place as the door mechanism will hold it 
correctly.