Ask HN: 3.5 inch diskette read errors, would a period correct drive do better?
I'm experiencing read errors with 3.5 inch diskettes and I'm wondering if using a drive from the same era (period correct) would improve my chances of reading them. I'm seeking advice on hardware and techniques for recovering data from old floppy disks.
A cheaper alternative is a GreaseWeasel (£30, $30). The 4.1 version even has USB-C as a connector. You will need an external power brick with a 4pin Molex connector for 5.25 drives. You can buy these standalone or they might come with a SATA/PATA/IDE Hard Drive to USB converter. Can also use an old PC power supply if you fake the power on signal. I've had quite a lot of success, almost 100%, over quite a long time - both 5.25 and 3.5.
I did use older drives intended for "desktop" machines. The drives from Japanese companies seem to be the most reliable; NEC, TEAC. The 3.5 USB Portable diskette drives are based around laptop floppy designs. You won't be able to find a direct 5.25 to USB adapter (or modify one to work) as the speeds / data rates are all wrong, so you will need something like a GreaseWeasel or old PC for those.
I've used different reading mechanisms over the years; an old PC running Linux with a real floppy chipset + custom raw reading code, custom hardware with an F82077 + Atmel + SDCard, and most recently a GreaseWeasel. The floppies I've recovered were stored relatively well, but were mostly my and family members data - not commercial floppies.
If there is any copy protection on the floppies you are trying to read you may need to capture the flux transitions. For these, I'd check archive.org to see if someone has already generated a copy.
For 5.25 floppies fingerprints and surface blemishes can be softened / removed with ISO Propyl and a Q-tip. Floppies designed for cleaning the heads of drives seem to now be very expensive / non-existent. Manually cleaning the heads of a 3.5 drive is way more difficult. I've got ideas about using Face mask / filter material to create a cleaning tool, but it is on the experiments to try list.
Even back when floppies were a thing, I found that 3.5 drives were more un-reliable between machines than 5.25 drives. I think there was more variation in head alignment and track positioning. When I've had issues, I've always been lucky in that switching the drive vendor / model made reading the floppy possible even if it took multiple attempts or was very slow.
- vunderba
Learning Company software has been pretty well archived at this point. To me, the easiest approach would be to hold onto the original box/packaging for sentimental purposes, and just find a copy of it on a site like the Internet Archive.
If your goal is to use it on a period-correct system, I’d go with 34/40pin adapters that lets you read flash cards, USB, etc.
A lot of my friends have kept their old 486 computers, and everything is period-correct except for the hard drive and floppy drive which have been replaced with a CF-to-IDE for the HDD and Gotek running FlashFloppy firmware for the 3.5".
- PaulHoule
10 years ago I heard “you’d better read all the floppy disks you’ve got now because you won’t be able to do it later.” You might do better with better hardware, you might not. This thing can get at the raw data
https://en.wikipedia.org/wiki/KryoFlux
which might let you get most of the bits from a bad block. See
https://goughlui.com/2013/04/21/project-kryoflux-part-1-the-...
- JoshTriplett
If you have something that's not already archived on archive.org, you might consider reaching out to Archive Team, who may be able to help you figure out the best way to read it accurately and avoid any errors.
(If you have something that is already archived on archive.org, the best way to get an accurate image of it would be to download it from there.)
https://archive.org/details/msdos_Super_Solvers_Spellbound_1...
- rietta
The disk appears visually in good shape. It has been stored all these years in the original box in an air conditioned basement. I am not seeing any white material or other obvious corrosion. However, I can confirm that my first attempt to read the imaged data failed. I did not record the output from ddrescue but it was something like 34% on the 1.4 MB. Got a corrupted screen when trying to run the installer in a Windows 98 SE QEMU vm. I have not dug into it very deeply.
- kazinator
Your idea is sane. You're already facing the problem of degradation of magnetic media; compounding it with dubious hardware isn't helping. Why can't that disk be read? Is it the disk, or this drive of dodgy origin? Or some combination of both?
An old drive will likely benefit from some cleaning: head, contacts.