Bad Blank Disks - ?

[KLund1]

I got a batch of 20 NOS sealed Memorex 1S2D 5.25" disks of evilbay for $25.

I got them for an XT I'm restoring. I can not format them. On the XT I get Track 0 Bad. I tried several 360K drives I have. All give the same result. So I tried on my 1050. With Dos2.0s I get error 10K. With SpartaDos I get error 255.

I did some GG'ing, and found that a Bulk VHS eraser might work. I do not have one, nor want to get one. Any hope for these disks? Ideas, suggestions?

Thanks

[Rybags]

Bulk eraser probably not a good idea, they can put a bias in magnetic media that remains persistent and can cause data errors later on.

 

Besides that, little point. The reason to use them is to destroy sensitive data before you throw tapes out. In any case, formatting disks isn't about zeroing everything, it's about doing the initial sector layout which is a mix of 1/0 bits anyway. And I believe Atari drives invert the data bits anyway (?)

 

Maybe inspect the disks themselves. Is oxide coming off? Does the colour look right? Do they spin easily in their jackets?

Edited January 10, 2018 by Rybags

[_The Doctor__]

please post picture of box with particulars and of disks...

there might be a tpi or other such miss match... doubtful but possible

it is also possible they could be hard sector or indexed disks... etc...

1s2d is not enough info for certainty

Edited January 10, 2018 by _The Doctor__

[Rybags]

TPI wouldn't matter, that's just a certification type thing and 40 track disks were bottom of the heap.

 

Supposedly hard sectored disks can be used on the Atari just fine, at least on the 810 and 1050.

 

Where trouble can arise is high density disks since the media coating is thinner - other things considered that's where I'd be looking next.

[+Nezgar]

make sure read/write heads are cleaned off with isopropyl alcohol using qtip, don't get the 1050's pressure pad wet. Also as previously noted look for visible blemishes. You can test with one disk first by cuting one edge off the case and sliding the 'cookie' out and giving it a little wash in warm water.

 

1S disks were basicaly a way for manufacturers to sell from the reject pile... and I would lean towards these being 'older' as you would only see the 2SDD/DSDD variety later on...

 

But I also have disks from 79 that work better than much newer ones...

[_The Doctor__]

173 - BAD FORMAT
177 - BAD DISK

 

what error did you get? 10k?

 

in any event try DOS 2.5 and give single density the enhanced density format, notch the disk and try the other side.... use a fresh disk from the box, the XT could be ruining the disks...

 

clean the drives and let them dry....

Edited January 10, 2018 by _The Doctor__

[Keatah]

I had to treat NIB old-stock memorex disks with a q-tip buffing before they'd work. Now they're fine.

[_The Doctor__]

ewe. grey brown q tips blech! those disks probably slowed the drives rpm's and dirtied the heads...

Edited January 10, 2018 by _The Doctor__

[1050]

Bulk eraser might work indeed but I would attempt the

cheaper hard drive magnet method first myself. And I

often do even though I've had a bulk eraser for 40

years, it gets used too. Just place the disk on a

non-magnetic desktop and wrap any rare earth magnet

in a paper towel and wipe it across the disk like

you were mowing the lawn only half width at a time

and over the full jacket dimension. Fast as you can,

or slow as molasses makes no difference.

 

Erase head will take the magnetic media well beyond it's

saturation point 40,000 times a second in an alternating

pattern which means no remaining bias is even possible.

MS-DOS does respond to this trick and especially when

the error given is bad track zero. You can try it twice

if it still reports bad track zero, but the chances of

actually having a good disk are not so good with 2nd

wipe and attempt error report.

 

I reach for the magnet only because I don't want the

hassle of untangling the power cord on the bulk

eraser, either method gives the same result which is

a high useful return on bad track zero reports. 5.25

and 3.5 disks.

[carlsson]

Last week I participated in a discussion where someone was trying to use new, old stock floppy disks that only clogged down the head on the drive. He had to take apart the mechanism and clean the head after trying each disk. Older, used disks still worked fine in the same drive. A few of the NOS ones worked as expected. He was told to take a q-tip with isopropanol or water and see if the disk would leave a residue before inserting it. Apparently some disks are really getting on the verge of not being usable anymore, perhaps depending on how they were stored.

 

You should probably be glad these disks only failed to format, not dirty the drive.

[Keatah]

Most of the aging issues with disks are in the binding material and lubricant layer. The binding material dries out, and sheds oxide. The lubricant layer dries out and becomes rough. Eventually the disk sheds a bit, at first, then more and more later.

 

Some disks are manufactured to good quality standards and this degradation process hasn't even started. Others, totally unusable.

 

Most memorex disks have thick lube layer, some of it dries up and clogs the head. Qtipping it buffs the top, and leaves a fresh surface. When you buff a disk, you don't want to see too much brown material or none at all, that's the magnetic particles.

[Bryan]

Yep, it doesn't matter if disks are used or not. What matters is how they're made and how they've aged. In my experience, buy some Sony, Maxell or 3M DD disks and you'll have a good chance. These disks are my absolute favorite because they're not made like the others and I've never had a bad one:

 

https://www.ebay.com/itm/Datalife-Plus-Verbatim-10-Minidisks-Teflon-New-Sealed/401472066055

 

If the disks you have are failing, you may need to clean all those drives before you use them again.

 

http://atariage.com/forums/topic/235272-best-525-floppy-disk-brand/?p=3509668

[KLund1]

Looking at the disk in the light just the right way I can see cloud shaped outlines. I think this could be that fd mold starting to form. I will try a distilled water wash and see what happens.

I do not like the Q-tip through the R/W opening. It takes too long. I'll use and Xacto-knife opposite the R/W opening and slide the disk out. Wash lightly with micro-fiber cloth on granite counter top. Dry, dry, replace, clean drive heads again (aaahhhrrrr), test. if that dose not work. i'll try ISO, is that dose not work, I'll try a HD magnet I think I have somewhere. I'll yet you all know.

Thanks for all the input!

[carlsson]

Sony, Maxell or 3M [..] are not made like the others

 

Strangely, back in the days the manufacturers didn't gloat about how long the surface would retain its magnetism. They would mention data reliability, how hard it was to open the plastic jacket and similar features.

 

Although Elephant Memory Systems kept mentioning that an elephant never forgets and that their disks were 100% guaranteed for a lifetime of heavy use, I suppose they didn't expect that lifetime to be in the range of 30-35 years. Others may have been using that 100% figure too, but for shorter values of 100% regarding to longevity.

Edited January 11, 2018 by carlsson

[Bryan]

Typically, the cloudy look isn't from mold. It's the glossy lubricating coating breaking down.

[Bryan]

 

Strangely, back in the days the manufacturers didn't gloat about how long the surface would retain its magnetism. They would mention data reliability, how hard it was to open the plastic jacket and similar features.

 

Although Elephant Memory Systems kept mentioning that an elephant never forgets and that their disks were 100% guaranteed for a lifetime of heavy use, I suppose they didn't expect that lifetime to be in the range of 30-35 years. Others may have been using that 100% figure too, but for shorter values of 100% regarding to longevity.

In my experience, the main problem isn't with the magnetism of the oxide layer. It's the longevity of the binder (oxide glue) and top layer. Oxide is useless once the other components aren't holding it in place.

 

Elephant was a brand of Leading Edge and was just a marketing gimmick since they bought the diskettes from other sources. They were cool looking disks, though.

[carlsson]

Ah, did Elephant just resell some OEM brand? I may have owned just a few of those. I saw the ads in COMPUTE! but I don't think the brand ever was marketed on this side of the pond, so the ones I've got must've been imported from somewhere at some point.

 

I've got a 100 pack of unused SKC SSDD disks. I've tried a few. Some work, some don't but so far none has clogged my drives. From now on I'll probably take swab samples before inserting them.

[Keatah]

I like the rotate the disk 10 degrees, swab with q-tip, and repeat. It puts the right amount of pressure on the media, but it does take time.

 

So I replaced the pressure pad in the drive, replaced the motor with a stepper motor, and built a simple timing circuit to advance the disk and the head. Next step is to rotate the pad so there's always a clean surface.

[KLund1]

I did it. But ran in to a lot of problems. First these disk selves DO NOT want to come apart. They are glued along the entire edge with over 1/4" of nearly beyond superglue level glue. Not heat melted. I first tried an Xeacto knife. Too much angle, and sliced it up good. Next, flat razor blade. laid it flat, but had to push so hard, it went out the outer edge! Tried flat at an angle 45' to the edge. Again had to push so hard the blade went through the edge again.

I have opened up a number of disks over the years, and these by far were the hardest to open. So this first disk is now open, but the back edge will never be the same.

The only way I can open these up without major damage is to slice off the left edge with an office paper slicer. I took off the left 1mm or less.

Now the cleaning. I first used distilled water on the granite counter top. DO NOT DO THIS! the disk got a bit of water under and it stuck hard to the counter top as I pressed down while wiping! I was able to slide it off the edge of the counter. Next I put down a thin cotton dish towel, and put the disk on that, and wiped with a microfiber towel. Ok good. I did both sides. Near the end of my wiping, I caught the edge of the disk with the back part of the towel in my hand, and proceeded bend back the disk putting a long crease in it!! I did this to 7 disks!! Your have to be very careful!! wipe, lift, move, put hand/towel down, wipe. Lift and move got me. You HAVE DO this part SLOWLY!!

Now to the testing. I put some but not all in the 1050. They formatted properly in dos 2.0s and DOS 3 (double density). I booted to the XT with DOS3.3. I put in a 1050 formatted disk, and the XT would not format it. I put in other 1050 formatted disks, and got the same message. Very odd.

I put in an unformatted disk in the XT and it formatted it. I put in the other unformulated disks. The first disk is the only one that did a complete format. The others had anywhere to 10K to 40K bad sectors. OK, I took those and did a ISO wash, I bent 2 more disks! I tried formatting the rest again, and they were about the same number of bad sectors. I opened up the XT and Drive and did a head clean. It was still clean, nothing on the q-tip.

Just to test I booted up another XT to DOS2.1 and did a format of those same disks. I got better numbers. but no perfect. I reformatted the same disks again then I got a full format. I did the same with the 1050 formatted disk, and it took 2 formats to get a complete format.

Now I have not tested the disk with any data yet, I'm tired and will try another day. But I find it odd that Dos3.3 will not format disks Dos2.1 will. I guess less error checking in the earlier version?

[Keatah]

I don't like disassembling a disk, unless absolutely necessary or it's something critical or the inner lining gives reason for inspection. The risk is too great. Then again I'm coming from the position of an archivist, whereas reviving boxes of blank disks isn't a big deal. Mess one up, throw it away.

 

I'm not keen on bulk erasers, unless the disk is destined for disposal. BE can put a strong field on the disk, and this can even transfer to the R/W head thus requiring demagnetization.

 

Pro-Tip for using head-cleaning diskettes, the white fabric type. Put the fluid down in one or two spots so that as the disk spins the head encounters alternating wet-dry-wet-dry areas.

 

Amateur-Tip for using head-cleaning diskettes. I used plain old tap water a couple of times instead of the official fluid. It worked fine. Do at your own risk.

Edited January 11, 2018 by Keatah

[_The Doctor__]

Use distilled water my friends, or de-ionized water.... trust me tap and mineral waters as well as most filtered waters are bad news... dissolved solids are bad news

but zero water hey go for it..

Edited January 11, 2018 by _The Doctor__

[Keatah]

There have been a few cases where I added talcum powder to the water to make it more abrasive-like.

[_The Doctor__]

hell no that stuff spreads everywhere. and where it collects with oil, grease or other such things... it turns to plaster and dries like concrete or drywall....

not to mention all that it can cause cancer blah blah blah...

Edited January 11, 2018 by _The Doctor__

[KLund1]

So where to get disks that are 'in like new condition'?

No dirt, NO fungus/bacteria growing, no rust, or carbon build up, no residue deposits on R/W heads (major issues with me, I hate cleaning heads every day of use!!, You never know what disk might be the bad one).

Obviously, my disk cleaning skills are an issue.

[_The Doctor__]

Buy government surplus disks in bulk, they have one or two that are dumping them on ebay...one of em is KAO, I forget the other... but I'm sure someone will chime in.. I really haven't had too many issues with new old stock name brand disks though when perfectly sealed, every once in a while you get a bad box...

Edited February 1, 2018 by _The Doctor__