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tezza
February 15th, 2009, 03:16 PM
Hi,

I was helping a friend yesterday transfer all his software and files from single-density, 5.25 inch TRS-80 Model 1 disks into disk images on the PC using a SVD device (http://www.classic-computers.org.nz/blog/2008-10-05-transferring-disk-images-to-real-disks-for-the-system-80.htm). Like my own stored collection when I tried this exercise, many of his disks looked like the below.

http://www.classic-computers.org.nz/blog/images/08-9-20-appleII-bad-disks.jpg

In the main, these didn't go into my drive but were simply thrown on the discard pile (similar to the discard pile above from an earlier exercise). However, one of these disks (which looked like the above) had some document files on it, which were really important to my friend. Knowing how thoroughly my drive was gummed up last time it tried to read disks like that, I hesitated to even TRY to read the data.

Anyway, my friend had heard of this (last-resort) technique where you cut the disk out of the sleeve and washed the gunk/fungi off with warm soapy water. I was EXTREMELY skeptical about this but as he had nothing to loose, he tried it anyway. The sleeve was cut away and the (now circular) disk duly washed with warm water and liquid soap. Lots of ugly brown gunk came off (better down the drain than on my drive heads!). The mylar was then dried.

He then inserted the disk (without the sleeve) carefully into the 1/2 height drive we were using and clamped it down. The drive was naked, so we could see it was being held into position ok. I then started to copy the files across.

Well, EVERY file was successfully copied and there was NOT ONE parity error in the whole copy episode (about 100k of data)! I was AMAZED and would not have believed it if I hadn't seen it with my own eyes!

Naturally my friend is stoked about this. He's now taken some of the other "rejects" home to cut out and wash. I'll be interested to see if we get the same positive result. I really can't believe it.

It seems floppy disks are far more durable than I gave them credit for. I'm not saying this will work all the time, or at all for others. It may depend on exactly what's wrong with the disk and how the disk was manufactured. However, it definitely worked in this instance. If you have gunk-laden floppies with very important data you really need to get off, and the only alternative is to chuck them, I'd recommend extracting and washing them AS A VERY LAST RESORT.

On reflection I'm glad we didn't try to read this disk as it was. The deposit would have certainly came off and scratched it, making it unreadable washed or not. It would have definitely gummed up the drive.

Tez

Chuck(G)
February 15th, 2009, 05:38 PM
I'd recommend a final rinse in distilled water if you have hard water in your area.

I use Freon TF to clean floppy cookies the same way. You haven't seen dirty until you've gotten a batch from a machine shop or auto repair shop.

hargle
February 15th, 2009, 05:46 PM
wow.
just wow.

I'd always thought this was an urban legend from the lunchroom of tech support workers. ..."please insert a clean disk into your drive"..."ok, hang on a second"...sound of running water in the sink from the next room...

i never would have thought it was possible!

vwestlife
February 15th, 2009, 05:55 PM
I have some floppies that have that same kind of gunk on them -- a set of thirteen 360K installation disks for MS-DOS 6.22 (which shipped on high-density 1.44MB floppies, but you could send in a postcard to get a free set of low-density 360K or 720K disks). For some reason, Microsoft didn't put hub rings on their 360K disks (making them look like 1.2MB disks), and this is right where the gunk has grown on the mylar -- around the hub.

Thankfully I have no pressing need to use these disks anyway, since I also have PC DOS 2000 which is superior in nearly every way.

nige the hippy
February 16th, 2009, 02:13 AM
That's remarkable!
I suppose you could cut a slot in the side of a floppy case to make a "caddy" if necessary.

chuckcmagee
February 16th, 2009, 03:48 AM
I did the caddy trick with some Northstar Horizon floppies I have. There was something wrong with the original sleeve (was stored in the drive, with the computer, in the shed, for who knows how long). Another old floppy sleeve was a strong paper/plastic combo with the top folded over and tacked down, like tack welds. I just cut the welds, opened the flap, and put the other media inside. Until my working double density controller arrives, the caddy diskette is the only one that will boot the computer now.

Trixter
February 16th, 2009, 08:30 PM
http://www.classic-computers.org.nz/blog/images/08-9-20-appleII-bad-disks.jpg


That first image is what I found trying to read a diskette a few days ago -- I pulled it out and immediately winced because I HAD to have data off of that particular diskette. I was afraid to do anything to it, so I did the stupid thing: I put it in and just kept hitting "retry" to "retry, abort, ignore" until the CRCs magically aligned and I got all the files. Took 10 minutes. I looked at the disk and drive afterwards and the heads had literally scraped the gunk off (it was now on the heads).

The heads were cleaned, but the disk was toast (had grooves in it).

There was probably a better way to handle that, but I was in for a pound, if you catch my drift...

patscc
February 16th, 2009, 08:42 PM
nige the hippy said...I suppose you could cut a slot in the side of a floppy case to make a "caddy" if necessary
Finally, a use for all those 5.25" HD floppies.
patscc

TandyMan100
February 17th, 2009, 03:51 AM
That's just nuts... I'll have to remember that.

carlsson
February 17th, 2009, 06:56 AM
Finally, a use for all those 5.25" HD floppies.
With all the chemistry going on lately, can't somebody come up with a formula to dip high density floppies into making them double density? :-P

Erik
February 22nd, 2009, 08:45 AM
I was doing that back in the early 80s with Apple ][ disks.

It's always best, however, to put the naked, cleaned disk back into a sleeve cut from a new/clean disk just to keep it from flexing too much when it spins in the drive.

This will reduce possible data errors and damage to the disk or heads.

Micom 2000
February 24th, 2009, 06:42 PM
I would be very cautious with that procedure and dry it off very well if you do try it. The consensus is that what causes disk-rot is atmospheric moisture which weakens the glue bond between the disk and the oxide coating. That might be the only solution however with disks which have accumulated gunk after long periods of use.

Lawrence

Bungo Pony
March 15th, 2009, 05:37 AM
My C-64 floppies went through my parents' house fire. I was not allowed to retrieve them until a month later. I figured they might be okay with just a bit of smoke damage.

Nope. They recieved a huge bulk of what came out of the firehose, so they were wet, smokey, and starting to grow mould. What I ended up doing was taking a bunch of 5 1/4" floppies that I never used (HD ones), cutting the edge on them, and pulling the magnetic disc out.

I then would cut open my C-64 floppies, clean them with a damp cloth, put the disc in the clean empty sleeve, and then copied them over to my laptop. I was able to save about 50% of my my disks, and 80-90% of my most important data (software I had written).