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 <mac_tech@tech-center.com
From: Rebecca and Rowland <rebecca@astrid.u-net.com 
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.
.