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Do not trust your old diskettes

Posted on Saturday, January 5 2019

During the holiday season I found some time to dig through my old computer equipment, mainly because I was looking for some old data that was stored on my Acorn RISC PC. I was lucky and found what I was looking for, but transfering the data to my current computer was a bit more challenging...

I will spare you the details about getting my old Risc PC up and running again, after it had not been used for over 15 years. Only in 2010 I seem to have had turned it on once, at least that's what a note I left there suggests.

Since the data files were relatively small, I thought it would be the simplest way to just take a bunch of my old diskettes from the 1990s and copy the files onto them, then read it back to my notebook using an USB diskette drive. That's what I kept these old disks around for anyway.

I have my diskettes stored in a wooden box in my home. Nicely packed, in a dark and dry place, always kept at room temperature. I knew they were okay, when I put them into there, so they should have done well. But they didn't.

Taking the first disks and trying to format them immediately gave me disk errors! It wasn't possible to format them neither under Linux nor under FreeDOS, nor using the Risc PC itself (which is also capable of formatting standard DOS diskettes).

Now, this doesn't come as a surprise, since it is just normal that diskettes of that age get defective at some point. However, I was surprised that they went broken while not using them and having them stored under perfect conditions.

I decided to take my remaining empty disks from the box and check them by reformatting them with an additional verification cycle. Here is the result:

Ratio of defective diskettes
Ratio of defective diskettes

I had a total 83 HD diskettes and 13 DD diskettes that were stored in the box. Of the HD diskettes 22 turned out to be defective (26%) and of the DD diskettes 2 (15%) where unusable. So in total 24 of 96 diskettes (23%) could not be used anymore. Just from lying in the storage.

Luckily, these where only empty disks, so it didn't do any harm. And for all of my data disks I have backups in the form of disk images. But after all, the main takeaway from this experience is: Do not trust your old diskettes! Never leave any important data stored on them without having made an image or other kind of backup. Old diskettes get broken, even if stored under optimal conditions.

Tags: ancient