3 1/2″ disks vs the 5 1/4″ disks…

So I’ve been talking with Frank Sapone about recovering old data and how I’ve had the worst luck with old 3 1/2″ disks.  Even sealed stuff like the MS-DOS client components of SQL Server 4.21a which Microsoft chose not to put on the CD-ROM, but rather on floppy diskette … which are not readable.

What is surprising is that not only has he had the same luck with 10-15 year old 3 1/2″ disks, but with 26 year old 5 1/4″ disks is that he can read them fine.

That is right, 26 year old  disks work fine with a good Panisonic 5 1/4″ drive mechanism, including a box of random disks he bought on e-bay that went through the old fashioned metal scanners, that he thought at best was a bulk lot of junk, he could read 100% of them with no errors.

I can only wonder how many people are sitting on ‘good media’ still factory sealed to only find out they are completely worthless.

If you’ve got old stuff, you better read it NOW… Otherwise it’ll probably never work, esp if it is 3 1/2″.

9 thoughts on “3 1/2″ disks vs the 5 1/4″ disks…

  1. I want to hear Tor’s experience on reading 8″ floppies if/when he is able to find time to verify their contents.

    That’s some pretty rare stuff, and we’ve discussed the price and research involved in getting one on a ‘modern’ dos box (i.e. mid-late 90s era stuff).

    • Yeah, I hope to get some time to read those 8″ floppies somewhen during the next months. I have everything I need to get it done. Presumably I’ve got two ways of doing it: 1) With my current Linux setup for 5 1/4″ floppies, plus a D-bit fdadap adapter. This setup has been used by others and should work. Or 2) Via a Kryoflux adapter.

      I also have access to a colleague’s Shugart 8″ drive, and, importantly, its original power supply.. which has got some _huge_ capacitors on board to handle the surges during some of the drive’s operational phases (my colleague told me he had tried the drive with a supposedly large enough PC PSU, but due to the surges it was useless).

      And, re. what I wrote in that other thread, my 5 1/4″ and 3.5″ experiences match up pretty much exactly with the above story. I think my oldest 5 1/4″ floppies are from 1986. All the oldest read fine. Some of the floppies are original vendor floppies (from a minicomputer manufacturer, mostly), and some are my own backups. There were two 5 1/4″ floppies from around 1990 that I couldn’t read a single bit out of, so I think they must have been stored near a magnet or something at some point.


  2. The ones I have are a mix of originals and backups ranging from 1986 up to about 1992 or so.

    Just a theory, but all of the backup disks were 3M and Verbatim and their quality feels well-built. Maybe that could also be part of it.

  3. I have much the same experience. 5 1/4″ floppies are much more reliable than 3 1/2″, and in fact were back in the early 1990s. The 5 1/4″ media needs better handling and care to avoid physical damage, but the lower bit density seems to significantly contribute to the data integrity.

    I’ve actually had pretty good experience with 20-25 year old 3 1/4″ media but they are definitely more sensitive.

  4. After this whole little discussion, I went back and tried to read my stack of 3.5″s I backed up about two years ago and three of those disks were already bad! They’ve sat next to the computer this whole time out of direct sunlight and the room was temperature controlled. Luckily, I had images on the drive as well (and online).

    So guys, if you have /any/ floppy disks and the time I’d recommend you get WinImage and start backing them up now!


  5. I think that the only reliable 3’5 inch diskettes are the 720 Kb. I don’t understand why 1’44 Mb become standard. I have several 3’5 720 disks and all are readable.

    p.d. Sorry for my English…

Leave a Reply