[Coco] Slightly non-working floppy drives

[Robert Gault]

Christopher Smith wrote:
> So, I have managed to get a set of working drives on my CoCo.  I also have two older, full-height, belt driven monstrosities which don't seem to be working quite right.  Disk formats don't complete on them, I can't backup a disk on them without an IO error.  What are the chances they just need cleaning?  Don't have isopropyl handy for now, but is that a good thing to try on the drive heads?  Might the problem be somewhere else?
>
> Chris
>

Isopropanol will not hurt the heads but what you normally can buy, rubbing 
alcohol (50% isopropanol) has been diluted with water. If you can get the pure 
stuff from a lab or druggist, it will work better.
If you can't get 95+% isopropanol, try a commercial tape head cleaner.

There are other reasons why tape drives stop working. The speed may be incorrect 
and can be adjusted with the strobe pattern on the drive. The head may have been 
knocked out of alignment and fixing that normally requires a calibration disk 
and a scope, or a special program.
I've seen the diode that shines through the notch in the disk fallen out of 
place. Setting it correctly restored drive operation.

Your disks may be squashed such that there is too much friction when they spin. 
That can permanently damage the magnetic surface. Such disks can be rejuvenated 
by breaking the seals on the jacket, removing the actual disk making sure that 
you can reinsert it without it being flipped over, and spreading the jacket 
edges. When the disk is reinserted into the jacket, there will be more space 
between the jacket and the disk permitting spinning with much less friction.

Robert