[Coco] Slightly non-working floppy drives

[Christopher Smith]

----- Original Message -----
> From: "Robert Gault" <robert.gault at att.net>
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Sent: Thursday, October 10, 2013 5:17:34 PM
> Subject: Re: [Coco] Slightly non-working floppy drives

> 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.

Usually you can get 95% around here with no trouble.  99% can be ordered.

> 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.

I was looking at those markings on the drive wheel... Figured that was what they were for.

> 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.

Disks are new(ish) and have been sealed until recently.  Also, they work fine in a different drive.

Chris

-- 
Christopher Smith
Systems Engineer, Wolfram Research