recommended vs. working 3.5" and 5.25" diskette drives

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Joined: Thu Mar 28, 2019 6:24 pm

recommended vs. working 3.5" and 5.25" diskette drives

Post by ssybesma » Wed Apr 03, 2019 9:17 pm

Hello everyone,

I saw the list of diskette drives shown to work with KryoFlux. There are a lot of them.

I wanted to ask a different question since my search on the forums didn't find the appropriate thread.

Are there 3.5" and 5.25" drives known to produce better results than others (condition being 'same')?

I've read about mods done to diskette drives to improve performance and would like to know more about that, as well as anyone doing service on these drives to refurbish/tune up.

Given I purchased this great tool, I want to pair it with the best diskette drives I can.

After all it's still a matter of garbage in, garbage out.

These are the 5 drives I have right now which I would like to ship to someone to mod/refurbish/tune up, or else just purchase one already done. Cost is not an issue.

(2) of Sony MPF920-E -- mfg Apr 2004 & has normal 34-pin diskette header
(1) of Panasonic LS-120 SuperDisk -- mfg Jan 1998 & has 40-pin IDE header...can't be adapted to work?

(2) of Teac FD-55GFR -- mfg date unknown but at least 25-30 years old

(1) of Toshiba FDD6784L3B -- mfg date unknown but at least 25-30 years old

Thanks everyone!

Steve Sybesma
Brighton, CO USA

Posts: 204
Joined: Wed Feb 18, 2015 8:18 pm

Re: recommended vs. working 3.5" and 5.25" diskette drives

Post by SomeGuy » Fri Apr 05, 2019 1:26 am

Any IBM PC style or "Shugart" style interface drive can be made to work with a kryoflux. From there, how well it works depends on what you are doing.

Obviously you want to use a quality drive. Earlier belt-driven drives are not a good idea for archival. Some cheap drives may have various failures that would be obvious even during normal use on its origional computer.

If you are just reading/writing IBM PC or similar FM/MFM floppy disks, almost any drive will do.

Once you get in to in to dealing with GCR encoding, not all drives behave the same because IBM PCs never used GCR. Another recent thread showed that many 3.5" IBM PC style drives have problems with Macintosh 400/800k GCR Variable BitRate formatted disks. Teacs seem to be the best for this job.

With 5.25", some drives can have similar issues with GCR used by Apple II/C64 or other machines.

Then, different drives have different maximum number of possibe tracks. Some wizeguys like myself liked to format disks with more than 40 or 80 tracks. If you wanted to read them you would need a drive that supported the same number of extra tracks.

And on the flip side, there are only a few specific models of drives that are ideal for hardware modding so a Kryoflux can read/write "Flippy" disks without cutting an extra index hole opening .

I've seen some of those "comatiblity" threads, and I'm not even sure what they claim to be testing. I wish they would be more specific.

There are several example images, that I think are still included with the KF software, that are used to test the ability to write certian kinds of copy protection. But those tests are very narrow in scope.

Posts: 6
Joined: Thu Mar 28, 2019 6:24 pm

Re: recommended vs. working 3.5" and 5.25" diskette drives

Post by ssybesma » Fri Apr 05, 2019 4:14 am

Thank you kindly SomeGuy.

Alright then, my scope is limited solely to IBM-compatibles (so no GCR is what you're saying). The diskettes I have were all created on generic PC clones from 1991 onward (starting with Intel 80386SX-16 and up from there), using MS-DOS 3.31, DR DOS 6.0, Novell DOS 7.0 and Windows 3.0 up to the present. Last machine I used which had a floppy drive in was about 10 years ago using Windows XP.

In addition to what I said I have above, I found an NEC FD1231T 3.5" from August 2000 in one of my storage bins.

I honestly don't know which drives are belt-driven or not so have to find if I have any that are not.
I remember the days of tweaking number of tracks, etc...I used to use tinker with 'high capacity' formatters as an experiment, but 99% of my diskettes used the standard format the OS used (fortunately).

So what I would really like to do is find this 'John' guy who did calibration/mods/repairs/tuning and send some of my drives to him to do his magic. I have a Teac 5.25" that's in really nice 'physical' shape and same for a couple Sony 3.5" (both of which appear on the compatibility list).

Soon as I can get those cleaned up/tuned up I can get started in earnest. My KryoFlux arrives probably next week.

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