Ask Slashdot: Recovering Data From 20-Year-Old Diskettes? 375
First time accepted submitter Zilog writes "The end of the 3.5-inch floppy and the disappearance of associated drives showed to me the need to backup the tens of diskettes that accompanied my youth. Carefully preserved, these diskettes have proved readable for the most part — while some are approaching 20 years old. However, some diskettes have shown surface defects in areas with compressed archives (zip). Any ideas on how to recover (as much as possible) these bad sectors?"
Norton Disk Doctor (Score:5, Informative)
Find an old copy of norton disk doctor and use it to do bad sector recovery on those disks. I remember it working pretty well back in the day.
Hands down (Score:5, Informative)
If you can find one use a Superdisk [wikipedia.org] to read a floppy. The heads are much more sensitive and narrow and can read ordinary floppies better than a regular floppy drive. I have used this to recover data from floppy disks that were old/worn.
Clean and align (Score:5, Informative)
Clean and align the drive first, before you screw up any (more) disks.
To give an analogy that kids now a days can easily understand, its like trying to insert an old fashioned flash drive into a USB port full of peanut butter. It might work, it might even work most of the time, but it'll work better if its clean.
Due to the digital capture effect or whatever, you might only need one dB more signal or one dB less noise to go from a sector having a read error somewhere every time you read it, to having an errorless read.
If you have way more time and/or money than you know what to do with, you break out the oscilloscope and align the drive to that individual disk/track. Yes this takes a lot of time and gear, but if you really gotta do it... Basically you align to best SNR on that individual disk rather than to an alignment disk. If the drive that wrote the disk was technically out of alignment, this will save you. If the drive that originally wrote the disk was in perfect alignment, then this is a waste of time.
At the very least, clean the freaking drive. Using kimwipes and undenatured pure ethanol on the heads. You drink some ethanol as a toast to the computing gods after success or failure, doesn't matter which, either way you're doing a shot or its bad luck and the next disk will shed its oxide for sure. Everclear is supposedly pure enough to clean drive heads, and supposedly its drinkable. All I remember from my only experience with everclear was yelling some lines from a cartoon and throwing up, and there are disks I have not been able to recover, so take my cleaning solvent suggestion with a grain of salt. Kimwipes are hard to explain and may no longer be manufactured, but they used to be like a dustless, lintless fabric q-tip, at least in concept, sorta. I don't mean they were like a q-tip in that they were of a certain dia, length, and color, but more the general idea of a perfect cleaning fabric at the end of a non-conductive stick.
Re:Norton Disk Doctor (Score:5, Informative)
Somewhat better than Norton is Spinrite. Remember Steve Gibson's hard disk utility? The one that could recover "unrecoverable" errors? Works on floppies too.
ddrescue. (Score:5, Informative)
GNU ddrescue.