Alright, before anyone starts tossing molotovs at me, let me restate that
I'm not Paul Dunric, although some of his... experiment results would come
in handy now.

Three days ago, after a particularly long and boring electronics class I
passed near the university's computer junk pile. Now, I'm not usually the
type to dig around any sort of pile, even though there was probably enough
stuff there to rebuild a 286, or at the very least armor-plate an average
sedan. However, amidst the debris I managed to find two boxes (total of 19
pieces) of 5.25", DS/DD, 48 TPI floppies - exactly what a C= floppy needs.
Since I don't havy any qualms about scavenging it (because it should've been
legally recycled and is still probably usable), I picked the whole lot up.

Now, here's the problem. Although the floppies were encased in the usual
cardboard boxes, an inner plastic bag and the usual paper sleeves, I'm
slightly worried about how they'd work because of two reasons. One, the city
had a hailstorm not two days ago before I found them. Two, the outside
corner of the university building where the pile was (fortunately, the
floppies were slightly separated away from them) is a Karmann alley - if
there's even a hint of wind, you can expect about two or three dust devils
to form and sweep whatever dust is on the ground upwards.

In short, I'm not sure if the floppies had survived dust and moisture. If
you've ever cleaned a 5.25" disk, did you have to open it up or could you
"fix" it from the outside? Can regular ethanol on a cotton q-tip clean it
without damaging the mylar or the surrounding floppy "envelope"?

Thanks in advance,
-- Stealth

Stealth wrote:


> In short, I'm not sure if the floppies had survived dust and moisture. If
> you've ever cleaned a 5.25" disk, did you have to open it up or could you

You don't clean floppy disks. The rotating action of the drive "cleans"
the biscuit as much as it's going to get cleaned. In some cases, if you
have important data on a disk, you might pull the biscuit out of its
envelope and put it in a brand-new, sacrificial envelope just long
enough to read what can be read before throwing it away.

Rubbing the data layer with anything is a good way to loosen the
magnetic material.

Thus spoke larwe:
> You don't clean floppy disks. The rotating action of the drive "cleans"
> the biscuit as much as it's going to get cleaned. In some cases, if you
> have important data on a disk, you might pull the biscuit out of its
> envelope and put it in a brand-new, sacrificial envelope just long
> enough to read what can be read before throwing it away.

So, if I got you right, all that's needed is that I let the floppy rotate
naturally, let the paper layer of the floppy clean the dust and hope I don't
get a head bump? Well, at least something. :)

The floppies are probably "brand-new" in a sense that they've been tossed
away with said 286es - to be honest I haven't popped either of them into a
drive, but I get the feeling they weren't C= formatted.

> Rubbing the data layer with anything is a good way to loosen the
> magnetic material.

Point taken. No wiping the mylar.

I would be concerned with getting dust onto the drive head.

If I had found the disks, I would format them in one of the 286 floppy
drives; let the "trash" drives be the recipient of dust and dirt. If
they format OK there, then format again on a 1541/1571 for Commodore
use.

James
www.cbm264.com

"James @ cbm264" wrote ...

>I would be concerned with getting dust onto the drive head.
>
> If I had found the disks, I would format them in one of the 286 floppy
> drives; let the "trash" drives be the recipient of dust and dirt. If
> they format OK there, then format again on a 1541/1571 for Commodore
> use.

Good idea James.  Let me add a little about formating a disk that is 
pre-formatted for IBM, or has been previously formatted on a PC.  Sometimes, 
a 1541 will not like them, at least not at first.

If the disk shows less than 664 blocks free afrter formatting in the 1541 it 
still might be a good disk.  Format it a second time and see if the block 
count increases.

Anyway, good luck with old disks.  Even disks that have been reasonably well 
taken care of seem to be failing from old age.
-- 
Best regards,

Sam Gillett

Change is inevitable,
except from vending machines! 

Sam,

I've had problems with formatting 5 1/4" HD disks, but never a DD disk,
on a 1541.

OTOH, I have more problems formatting a 3 1/2" HD disk on my PC, then
taking it to my son's PC.... I get disk errors like crazy. Formatting
these same disks on his computer and they come up "Bad Media - Disk
Unusable". Take them back to my PC and they work fine IF I can get them
to reformat.

James
www.cbm264.com

> Good idea James.  Let me add a little about formating a disk that is
> pre-formatted for IBM, or has been previously formatted on a PC.  Sometimes,
> a 1541 will not like them, at least not at first.

"James @ cbm264" wrote ...
>
> I've had problems with formatting 5 1/4" HD disks, but never a DD disk,
> on a 1541.

It is only natural that you had problems with HD disks.  The 1541 does not
like them.  Not at all!    ;-)

I don't always have problems formatting DD disks that have previously been
formatted as 360K PC disks.  But sometimes I do.  This has happened with both
1541 and  1571 drives.  On an occasional disk, it will show less than the
proper number of blocks free after formatting.  When this happens, formatting
the disk a second time will usually fix the problem.

I have had the same sort of experience with 3.5" DD disks that had a 720K PC
format when formatting them in a 1581 drive.

> OTOH, I have more problems formatting a 3 1/2" HD disk on my PC, then
> taking it to my son's PC.... I get disk errors like crazy. Formatting
> these same disks on his computer and they come up "Bad Media - Disk
> Unusable". Take them back to my PC and they work fine IF I can get them
> to reformat.

I had something like that happen also.  First I tried cleaning both drives.
That didn't help.  Then I changed the drive mechanism in the computer that
kept trying to tell me the disk was bad.  Problem solved.
-- 
Best regards,

Sam Gillett

Change is inevitable,
except from vending machines!

Thank you all for the ideas, I'll mull over them for a while and get that
floppy batch checked. With any luck, the yield will be high and I'll have a
set of decent disks.

Cheers.

Sam,

It's been like this from the get-go. The only disk it'll read reliably
is the boot disk that came with it. I didn't have a spare floppy drive
handy, but I had network cables.... so I just plugged him into the home
network. :)

Yeah, I should replace the floppy drive, one of these days I'll have to
reinstall the OS.

James
www.cbm264.com

> I had something like that happen also.  First I tried cleaning both drives.
> That didn't help.  Then I changed the drive mechanism in the computer that
> kept trying to tell me the disk was bad.  Problem solved.