WHAT TO DO IF AN IMPORTANT FLOPPY HAS SHUTTER PROBLEMS
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Date: Fri, 28 Aug 1998 02:30:18 +0100
To: James Jung <[email protected]
From: Rebecca and Rowland <[email protected]
Subject: Re: MacSE & floppies

At 9:40 am +0100 27/8/98,
James Jung wrote: In Classic Macs Digest 980825, you said:

It is possible for any 3.5in floppy disc to destroy a disc
drive: if the shutter is a bit bent out of shape, it can snag
the disc drive head and rip it off its mounting.

Though this is a bit extreme (improbable), it is entirely
POSSIBLE.

I've seen it happen.

take care of your discs, and it won't (you only need to worry
when the shutter is splayed outwards so the two faces are no
longer parallel; it's possible to remove the shutter, bend it
back into shape, and re-fit it).

You might as well leave the cover off of the disk, since
removing it, bending it back, and re-fitting it may make
matters WORSE. If the metal shutter is not bent correctly
(which you, most likely, CAN'T), the disk may get jammed in the
floppy drive. With a paper clip in hand, you may not even be
able to unjam it, leaving you the only two options--open it to
remove it or buy a new floppy drive.

It's pretty easy to bend the metal cover back into shape in the
most common case of distortion: the most common fault is that
the two main right-angle bends are distorted so that they're
less than 90 degrees (harsh handling of the disc will do this
quite happily). After seeing the disc drive destroyed, I took
to checking students' floppy discs very carefully, and I've
performed the following operation more times that I can count.
This is not one of my guesses at how to fix a problem, nor is
it just speculation: it's something I've done myself many, many
times with no problems at all. Not all shutters *are* practical
to fix, but that's often okay - I for one have plenty of faulty
discs I can use shutters from.

Note: I use a knife for this job. There's a chance that if you
try what *I* do, the knife will slip and cut you, or (worse)
break and land in your eye. A thin bladed screwdriver might be
safer; I use a knife with a blade that can take the stresses
involved. Something like an X-Acto hobby knife or a scalpel
stands a high chance of snapping on you. A small, thin,
conventionally-edged kitchen knife might be better.

To remove the shutter, get a thin-bladed knife (I use the small
blade on my Swiss army knife), and look at the back of the
floppy disc (the side where you can see the metal disc at the
centre of the floppy disc proper). You'll see that the shutter
is held in place by two tabs bent over to engage in slots in
the plastic body of the floppy disc case.

Hold the disc with the metal shutter at the top. If you look at
the right hand side, you'll see that there's a bevel in the
plastic along the top edge about 15mm-20mm from the right hand
edge of the disc case. The first step is to slide the shutter
about 5mm (1/4 inch) to the right. In doing so, you should
expose half or more of the disc opening - be careful not to
touch the disc surface!

With the shutter held part-open like this, (very carefully!)
ease the knife blade under the metal of the shutter right up at
the top so the point is between the folded-over tab and the top
edge of the shutter. Once you've fitted the blade in carefully,
gently but firmly pull the metal towards you (to allow the tab
to disengage from the slot in the plastic). While you're doing
this, hold the disc case very steady and ease the shutter
upwards (to disengage the tab) with the knife blade.

With this done, the shutter will be half off. Note that there's
a spring at the end you've just disengaged. Just be aware of it
for now.

There's a similar bevel (that you can't see at the moment) in
the plastic case for the other metal tab that holds the shutter
on the disc case. What I do is this: keeping the shutter
part-open as before, ease the knife blade under the metal
shutter again: this time, I put the blade tip under the top
left-hand corner of the cut-out in the metal, and ease it in
until the knife tip is as close as possible to the fold in the
metal (where the shutter folds over the top and to the other
side of the disc). With the knife blade in position, I gently
but firmly pull the metal towards me and push upwards again
until the tab pops out and clear of the slot.

With this done, have a careful look at the right-hand side:
hold the disc so you are looking at the thin edge of the
shutter (the bit that folds over the end of the disc case).
You'll see a third metal tab - this is what the spring engages
with. The spring itself slots into the disc case (you should be
aware of this by now :-). Hold a finger of thumb over the place
where the spring slots into the disc case and ease the shutter
off the disc - mind you don't lose the spring! Once the
shutter's off, take the spring out carefully and put it
somewhere safe for now. Mind you don't touch the surface of the
disc itself with *anything* - especially not a bit of sharp
metal like tha spring or knife.

Put the disc down on a clean flat bit of paper for now.

With the shutter off, you can bend it back into shape with your
fingers just by squeezing the two right-angle folds so that
they're a bit sharper than right-angles (squeeze the folds
themselves - hold the shutter at the folded end and squeeze
together so the free ends of the shutter move together and
touch. You need to apply force to the fold itself and be
careful not to put a permanent bend in the flat sheets). If the
flat sides of the shutter aren't flat, the best solution is to
grab a dead floppy disc and take the shutter off that one to
use instead.

Now to re-fit the shutter. The only mildly tricky bit is the
spring. Fitting the shutter alone is child's play: hold the
disc case as before (so you're looking at the side with the
metal disc at the centre of the floppy disc proper showing),
slide the shutter back over the disc case carefully (be sure
that both metal plates are on the outside - it can be easy to
slide one of them into the crack between the two bits of
plastic that make up the disc case), and line up the two tabs
on the shutter with the two bevels on the disc case. With that
done, just press the shutter down firmly, and it should pop
into place.

You should now have a shutter that slides freely and is a snug
fit against the plastic body of the disc case. Assuming this is
so, you can fit the spring.

If you hold the spring so it's roughly like a splayed-out L,
you can fit the horizontal part into the disc case - look at
the edge of the disc case where it fits, and you'll see that
slides in (parallel with the very top edge of the disc case)
and settles right up into the top corner of the case. Now
gently ease the spring down - press on the `upright' bit of the
L so that the loop eases in to the slot in the disc case. Once
the loop's inside, gently ease the spring down. Notice the
small right-angled bit at the end? That needs to engage with
the tab I mentioned earlier. If you ease it in gently and let
it spring across *just* as it's low enough to do so, it should
engage correctly. The way to check is to move the shutter over
and see if it springs back (you should also be able to see the
very end of the spring engaged in the tab). If it does,
everything's okay. If not, take the shutter off and try again.
You might find it easier to engage the spring with the tab in
the shutter (and the slot in the disc case) before re-fitting
the shutter.

This is *not* a theoretical technique: it's something I've done
with great success times beyond count; I can only think of two
floppy discs that had shutters distorted such that they needed
replacing rather than just bending back into shape. I can
demonstrate it in person in under a minute; it's a bit of a
pain to describe in words. I've sat here with floppy disc and
knife to check that I've got it right.

How do you protect the disk, if it doesn't have a metal
shutter? EASY.

1. Don't touch the disk platter (the thing that the metal
shutter hides).

2. Get a sheet of CLEAN paper, wrap the disk in it, and TAPE
IT, so that the wrapping doesn't come apart. In other words,
you're making an envelope for it. (Make sure that it's not too
tight, so that you can't pull it out. Make sure it's not too
loose, so that the disk falls out. Make sure that none of the
edges/corners are on the inside to scratch the platter. If you
don't use tape, then it is useless, since it can come apart.)
In fact, this doesn't require an entire sheet of paper (8.5" x
11").

For those of you who object to this idea because of lint or
other microscopic particles on the paper, this method is just
as "dangerous" to the disk as having a properly-working metal
shutter on it. When a disk is in the floppy drive, the shutter
is OPEN, which allows for dust to land on the platter.
Additionally, particles can still get through the shutter,
since it is NOT a seal.

The biggest problem with the paper envelope technique (which is
used for 8 inch and 5.25 inch floppy discs) is that the paper
itself sheds abrasive dust. If you look at the envelopes used
for the older floppy discs, you'll note that the inside
surfaces are normally treated so that they're smooth and unable
to shed paper particles. Metal shutters don't shed much dust
either. Each time you remove a 3.5 inch disc from a paper
envelope, you'll be creating more dust. it's not the lack of
seal that's the problem so much as the fact that you're
deliberately exposing the disc surface to an environment with a
very high concentration of abrasive dust.

Look at it like this: normal paper is made out of wood. Paper
dust is basically fine wood chippings. Are wood chippings
particularly soft? No.

If you've no other way of doing things, sticking a 3.5 inch
disc in a home-made paper envelope is okay and probably much
better than nothing. Don't trust it for long-term storage. Over
time, most adhesive tape dries out and sheds dust and most
paper turns brittle and sheds dust (if you've got any old
paperback books, you'll know what I mean). Re-fitting a metal
shutter is preferable if practical.

For long-term storage, I wrap my discs up in plastic bags and
put them in disc boxes in cupboards. I have stored discs
wrapped (in groups of ten) in multiple plastic bags each sealed
up with adhesive tape - these discs have survived unscathed
many years like that, including one year in a distinctly damp
room with mould on the wall (far-off days as a university
student living in cheap rented houses in Manchester - the
original Manchester, not one of the transatlantic copies).

It's also possible that the bit of tape (used to trick 1.4MB
drives into thinking that the disc is really an 800K disc
drive) can peel off and snag on something.

I've done that, actually, to FIX disks. Sometimes, disks (with
shutters working as they should) end up getting dust/lint onto
the platter without my knowing. In a format/scan of that disk,
it would be marked as a bad sector. After removing the
dust/lint from the disk, subsequent formats fail to recover the
lost space.

This sort of problem is often caused by a dirty disc drive
head; whenever a previous okay floppy disc `goes bad' on me, my
first solution is to clean the disc drive with a cleaning disc
and TechTool. It has (so far) allowed me to read all the data
off the disc in question (which I then re-format just in
case...)

What I would do is turn it into a double density disk (In
insert-disk position, the tape is put on the left hole.), and
format it so. Most of the time, if the disk is NOT scratched,
the format will be successful (no lost space). Then, I would
remove the tape, and format it again as a high-density disk,
and the format would also be successful. Another scan of the
disk with Disk First Aid AND Norton Utilities will report no
problems with the disk.

I would never, ever, *ever* do this. If a disc has a missing
sector, so be it. I'd rather that the damage was noted and
locked out properly that try to use a (damaged) 1.4MB disc as
an 800K disc which is an iffy procedure at the best of times.

In case you think there's something inelegant about this, note
that *all* hard discs have some bad sectors which are locked
out in this way.

Fooling a disc drive into thinking a 1.4MB disc is really an
800K disc is no fix: it's sweeping the dirt under the carpet in
a particularly iffy way. Maybe it won't matter, but maybe
you'll end up with a colony of cockroaches feeding on it. Now
then... I don't like spending money, but I don't like losing
data either. I've had discs lose data (although it's only
actually lost the last coop of the data in question once so
far) often enough that I don't play silly buggers: if the disc
had a bad sector on purchase, I get it replaced. If a disc
develops a real bad sector in use (rather than having trouble
because the disc drive head was dirty) and that bad sector
stays bad on re-formatting, that disc is marked `iffy' and
*never* used as a backup disc. Paranoid? Maybe - but I don't
spend lots of money and I haven't lost any data (yet - touch
wood, fingers' crossed, etc., etc.)

This is unlikely (that's unlikely, not impossible) to cause any
*serious* damage: I have heard of one case in which such an
event resulted in a dead logic board (this was an extreme case
of a Mac trying to re-start repeatedly over a weekend because
it couldn't eject the disc properly).

IMHO, this is far-fetched. Rowland, you may be reminising over
the days when your videocassette tapes turned into spaghetti
(or worse) in your VCR.

It's far-fetched, but Jag has related the tale on the Classic
Macs mailing list. I might think uncomplimentary things about
him from time-to-time, but I think he's honest. I've never seen
a video recorder (as we call them in my part of the world) chew
up a tape in any way, although I've seen normal audio cassette
players do this quite often.

It's a plausible tale but not something I'd worry about, and
I'm *very* paranoid.

In my book, if it can happen, it will.

[snip]

Probabilities are relevant: I expect not to die because of a
meteorite strike. If I formatted a faulty 1.4MB disc as an 800K
disc... Well, that's like crossing the M1 (6 lanes of
high-speed[1] heavy traffic) wearing a blindfold.

Rowland.