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Problems with 3.5" HD Floppy Disks - Is it Just Me?

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wesleyfurr

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Just curious if I'm maybe doing something wrong or something I haven't considered, etc... Seems like any time I sit down and need to make use of a 3.5" HD 1.44Mb floppy disk, I have problems finding a good one. Today's example...though I guess possibly tainted by disks of unknown origin...picked up a box of 3.5" HD disks at a thrift shop a few weeks ago. Just pulled one out, stuck it in my PC (new-ish i7 with a slightly less new drive) and saw someone's QuickBooks backup. Stuck it in the Mac LCII I've been tinkering with and said yes, please initialize it...fail. Back to the PC and the format fails with unusable Track 0. Next disk, same problem. Third one formats just fine. The disks in question are TDK with a plastic "shutter".

Seems like any time I'm trying to make a boot disks, I'll grab a few HD disks and usually end out throwing 2/3 of them in the trash due to bad track(s), which of course is a problem with a disk image.

So what's going on here? Do 3.5" HD disks just not like me? I don't think it's likely a problem with the drive in my PC... Or were most 3.5 HD disks manufactured late enough that manufacturers were just making absolute crap in order to sell them cheaply? That's been my theory... Just curious if others are seeing the same problems...

Thanks,

Wesley
 
I've found 3½" disks to be way more reliable and less likely to fail than 5¼" disks. In any case, it never hurts to run a moistened head cleaning disk through the drive as old or crappy floppies can foul the disk's heads in a second or less.
 
No, the HD disks seem to degrade faster than the DD ones do--and the quality varies a lot. If I look at the stack of HD floppies sittin on the top of my system here (I have many HD floppies), the bulk of them are Imation 2HDs. Even though I bought many Maxells (with the plastic shutter), I don't have a single one in my "working" stack. Maybe not scientific, but a good random sample.

I've got a hundred or so HDs that need to be reformatted; one of these slow days, I'll get to it and let you know the breakout by brand.
 
Stone said:
I've found 3½" disks to be way more reliable and less likely to fail than 5¼" disks. In any case, it never hurts to run a moistened head cleaning disk through the drive as old or crappy floppies can foul the disk's heads in a second or less.
Click to expand...
And I've had the opposite experience, more issues with 3.5HD than either DD or HD 5.25's; just shows to go ya...
 
Yeah, 3.5" HD is quite a crapshoot compared to even 3.5" DD (well-kept 5.25" disks are, in my experience, better than either) - I think by the time there was a lot of demand for them, manufacturers had begun to cut corners on media quality, and by the time floppies were on the way out, they'd been making tons of the things with cheap, unreliable media.
 
commodorejohn said:
Yeah, 3.5" HD is quite a crapshoot compared to even 3.5" DD (well-kept 5.25" disks are, in my experience, better than either) - I think by the time there was a lot of demand for them, manufacturers had begun to cut corners on media quality.
Click to expand...

I think much manufacturing moved overseas. That was true certainly with Dysan--which had been one of the better brands.
 
Does the Mac work correctly with Erase Disk instead of Initialize? Been a while since I used the Mac but I remember that Initialize Disk tended to skip over formatted but unreadable disks while Erase Disk does a proper format.

I have been pleasantly surprised by the number of disks that I stored 25 years ago that are still readable. The one exception is the original 5.25" driver disk for an AST memory card which all my 5.25" drives think is empty. I think the peak of floppy quality was about 1990.

The worst set of disks I ever used were some Imac inspired designs (high density), thin translucent colored plastic which split open along the sides when inserting into a drive and only had a tiny piece of felt for dust handling. Looked great. None of them lasted through 3 insertions. Why bother with a shutter if sides aren't sealed?
 
Chuck(G) said:
No, the HD disks seem to degrade faster than the DD ones do--and the quality varies a lot. If I look at the stack of HD floppies sittin on the top of my system here (I have many HD floppies), the bulk of them are Imation 2HDs. Even though I bought many Maxells (with the plastic shutter), I don't have a single one in my "working" stack. Maybe not scientific, but a good random sample..
Click to expand...

I also found that the (newer) HD 3.5" disks are far less reliable than the DD's (even 5.25"). I have a whole box of newish verbatim 3.25" HD's of which 95% are rubbish. Funnily enough I also have a box of Maxells which work just fine.

I'm also of the opinion that a well kept 5.25" will outlast all the above. I have an old circa 80's verbatim brand disk which I use for transferring applications onto freshly formatted XT's. Still going strong after many many many writes/copies/rewrites.
 
Thanks for everyone's comments...that just helps confirm my suspicions. I'll begin using the trash can liberally again... :)

Thanks,

Wesley
 
commodorejohn said:
Yeah, 3.5" HD is quite a crapshoot compared to even 3.5" DD (well-kept 5.25" disks are, in my experience, better than either)
Click to expand...
That's my experience as well. I've recovered what I could from my old media (from back to the early eighties, depending on type). No problems with CCTs or 5 1/4" floppies (except for two of the latter that must have been degaussed or something), I have only a few 3.5" DD floppies - ok too, but I have not been able to recover a single complete 3.5" HD floppy. Not one. I have lots of them. Lots of drives too. No go. And they were stored in the same room as the rest. (I have some 8" floppies too which I have good hopes for - haven't got my setup for those ready yet).

-Tor
 
Even in their heyday they were unreliable flaky trash -- I've never liked 3.5" and to be frank, the technology compared to "normal" floppies has aged like milk. Hell, they make ZIP disks look reliable... which is really pathetic when the "click of death" is in the mix.

For my own data, the only thing I ever used 3.5" for was to walk across the room as Sneakernet, and even that was unreliable compared to 5.25". Other than that the ONLY reason I'd put up with them is if the software ONLY came on 3.5" or the system only had 3.5" -- which thankfully wasn't all that long a period of time thanks to optical coming quickly on the heels of the utter abandonment of 5.25"... even though CD's weren't all that great an improvement either.
 
I agree that 8" floppies were the most reliable. I try not to use floppies at all - yesterday, I took an IDE hard disk out of my Pentium 100 machine to put it on a box that could boot MHDD32 from a CD. But I have an HP 4952A protocol analyzer and a Tektronix TDS380 oscilloscope that both benefit from using the installed 3.5" floppy drives. I have several boxes of new 3.5 HD floppies that I bought years ago, but have problems more often than I expect. I'm about ready to see if the TDS380 will work with one of those floppy emulators that use a USB stick. I have one lying around, but I think there is only a slimline mounting space...
 
I suppose it makes sense that the higher the actual bit density the more likely it is that you'll have problems; I'd love to see a picture comparing the magnetic patterns of an HD 3.5" disk to an SD 8" one.
 
Don't know about a picture, but the information should be available with a bit of digging and perhaps a bit of math. Essentially, the transition patterns are spaced no closer on FM than on MFM (it's the position of those transitions that matters), you know that the clock rate's the same, so the big factors are flux changes per inch--you can calculate that, given the dimensions and rotational rate.

One advantage that 8" has over other formats is that the width of a track is greater--i.e., more signal.
 
Chuck(G) said:
Don't know about a picture, but the information should be available with a bit of digging and perhaps a bit of math. Essentially, the transition patterns are spaced no closer on FM than on MFM (it's the position of those transitions that matters), you know that the clock rate's the same, so the big factors are flux changes per inch--you can calculate that, given the dimensions and rotational rate.

One advantage that 8" has over other formats is that the width of a track is greater--i.e., more signal.
Click to expand...
True enough, but I'd think that with modern heads the length of the track is more important. The higher BPI of MFM vs FM does indeed not necessarily mean a higher flux changes per inch, but here's what Wikipedia says about BPI: (presumably all MFM):

8"DD 6,816
5"DD 5,876
5"HD 8,646
3"DD 8,717
3"HD 17,434

And of course the 3.5" drives will also have the narrowest heads, so it's a double whammy; no wonder they're the most susceptible to errors.
 
A condensed list of track widths and erase gaps can be found at http://retrotechnology.com/herbs_stuff/drive.html#data Interesting things to note is that the 8" track width and 5.25" DD track width are the same while the 3.5" track (including erase border) is much narrower. Not much room to correct for alignment issues.

The very thin 3.5" HD diskette can't be good for extended usage.
 
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Chuck(G) said:
...and then there's 3.5" ED...
Click to expand...

I was just thinking the same thing... :) I've got a pair of drives and a box of TDK ED disks here...have not yet gotten around to playing with them to see if all works...

Then of course there are the LS-240's capable of writing 32Mb onto a standard 3.5 HD disk......

Wesley
 
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