Floppy Disk Lifespan?

[dansalvato]

Hey, I have a question about floppy disks. My floppies have been used for 20 years now, and I was wondering if after a while they just sort of conk out. I know floppy data doesn't last forever, but suppose I were to write something new to the same floppies today - would it last? Or, should I just buy a batch of new ones?

I ask this because recently, I've been experiencing a LOT of disk corruption, even with something newly written to the disk, and I'm trying to pinpoint the problem. Thanks!

[s2325]

I think floppy disks last longer than floppy drives. I saw that most read/write errors were because people seem to like ejecting floppies too early, when data is still written.

[dansalvato]

I always make sure I eject the disk after the drive stops spinning. Should I buy a new drive, though?

[rkauer]

New drives are always HD modified versions to work with DD disks. So the magnetizing heads are obvious weaker than original DD drives, making disks less magnetized than the ideal.

Stuck with the original DD drive while you can.

[Rixa]

All my Amiga DD disks are 10-15 years old. I haven't had any break just using them write-protected, but if I start writing on them they develop errors after a while. I'm not sure why this is; the old drive, the old media, or just my old imagination.

[Photon]

I dunno if you suspect the internal drive, but --

Many old DD drives are getting dirty or failing; it's been 20 years folks. Get an A600 drive off Amigakit and MAKE IT FIT. :P Well, not really, but you get my drift. Nobody would expect every 20 year old PC floppy drive to work. Try a cheap floppy cleaner disk from Amigakit, and if it still fails writes, get a replacement drive or replacement A500 or something to fix it.

If you get a r/w error on a certain disk, you can write an adf to it to test it. If it fails around the same track, it's much more likely to be the disk. Most disks fail either on the boot track or track 60-79.

I have one (1) external floppy that has failed, but it's completely dead, so it's the electronics. I regularly clean the drive heads with cleaner disks, and when "some old floppy disk from some box" fails I throw it in the waste bin.

Another way to test your internal drive is to buy a pack of sealed new DD disks from tradera.com or Amigakit and copy the disk you have problems with to it. That will copy any tracks that already have errors, but if you write to an unused track and it still fails, it's the drive.

[dansalvato]

I took a bunch of old, unused disks and formatted them, and using those, I'm managing to copy more successfully. Unfortunately, many TOSEC games give me a key 880 checksum error, but endless searching hasn't yielded any practical solutions to that.

[Photon]

Well, I don't know if every single image of TOSEC is screened for checksum errors, they should be. But I also know I've had disks that have formatted perfectly and failed when writing "stuff that doesn't consist of all empty tracks" on it. So I usually just go "hmpf", get a lot of disks and throw away the ones that give any sign of trouble when writing images.

But that's just because I have hundreds of unused disks already If I weren't so cheap I'd just get brand new disks and save a lot of time... pity the ones on Amigakit are rainbow-colored. Silly reason really, but well... I have disks

[dansalvato]

Well, when getting the same error on multiple disks, especially a checksum error, ya know. =P (In this case, Prince of Persia.)

[TCD]

Originally Posted by Photon

Well, I don't know if every single image of TOSEC is screened for checksum errors, they should be.

Screened? Not sure about that, but if a checksum error is known, it's mentioned in the TOSEC name (e.g. Ashes of Empire (1992)(Mirage)(Disk 1 of 3)(Program)[cr FSN][b checksum error]). Maybe you use this disk image Haxxy : Prince of Persia v1.0 (1991)(Domark)[cr Angels][f AGA SKR][t +2 Angels][b errdms] (CRC32 : 8FCF2156) ?

Edit : I remembered there was something about this problem on this forum andreas made a tool to check for checksum errors in ADFs. So grab that tool and make sure you're not flogging a dead horse : http://eab.abime.net/showthread.php?t=40683

[mr.vince]

Originally Posted by Haxxy

Hey, I have a question about floppy disks. My floppies have been used for 20 years now, and I was wondering if after a while they just sort of conk out. I know floppy data doesn't last forever, but suppose I were to write something new to the same floppies today - would it last? Or, should I just buy a batch of new ones?

I ask this because recently, I've been experiencing a LOT of disk corruption, even with something newly written to the disk, and I'm trying to pinpoint the problem. Thanks!

Well due to different production batches of media it is suspicious if all of your media starts failing. Could e.g. be a small (tiny) piece of sand stuck on a sticky (=dirty) head, scratching media, or simply another hardware defect. Could also be as easy as a misaligned head.

Disks normally fail because they lose magetization (due to information being old) or because of media rot (the metal particles bound to the plastic platter become lose or worse the whole magnetic layer including the bounding material dissolves into pieces).

Originally Posted by rkauer

New drives are always HD modified versions to work with DD disks. So the magnetizing heads are obvious weaker than original DD drives, making disks less magnetized than the ideal.

Hmmm... from what I know bias and recording current are adapted when writing to a DD disk with an HD drive. But... I am sure HD drives are optimized for HD disks, not DD disks. Anyway, do you have more information on this or did you gather this from experience?

The really bad thing is all this happens in the drive logic before any controller can do anything about it. I know there are quite some differences between makers and models.

[Rixa]

Originally Posted by Photon

I dunno if you suspect the internal drive, but --
Many old DD drives are getting dirty or failing; it's been 20 years folks. Get an A600 drive off Amigakit and MAKE IT FIT. :P Well, not really, but you get my drift. Nobody would expect every 20 year old PC floppy drive to work. Try a cheap floppy cleaner disk from Amigakit, and if it still fails writes, get a replacement drive or replacement A500 or something to fix it.

I don't know.. I mainly use the drive for reading my old disks and none of them have developed issues without having been written to, so my gut feeling is that the old disks just can't take being written that many times anymore. But I don't really use disks that much, so this could also be just in my head.

I have this disk in the drive to keep it from clicking (noclick utilities don't make it stop clicking, just more silent) and it occurred to me I could as well keep some small random stuff on it to survive across reboots. Nothing important, just notes and random stuff I didn't want to keep on my internal CF. But I did keep putting new files there and editing the old ones couple of times a day. In a week or two the disk got some errors and wouldn't even format cleanly, so I replaced it. And after this repeated a couple times I figured it was not such a good idea in the first place.

Those new DD disks from amigakit, are they recently manufactured? I'm not even sure if that's a good thing or not. Certainly they're not worn out yet, but are they as good as they used to come back in the day? The few experiences I've had with PC disks/drives in the recent years have left me with the impression that disks are more or less disposable these days. People no longer rely on them, don't buy them in great volumes and don't want to pay much at all for them. Perhaps the production quality has gone down to keep the cost low? Or perhaps I've just dealt with really dusty drives. Anyways the minimum stack of disks to buy seems to be 25 and I don't want to get so many just to test them out

I notice that amigakit sells a "Amiga Internal Floppy drive (A1200/A600)", brand new. Might it be a modified PC drive, and what would be the implications of that? If I were to put money into a new disk drive, should I maybe look for a HD solution while I was at it? I've never had one in an Amiga.

[Photon]

Well, don't knock off-the-shelf products beforehand If you're saying "yeah, it's a DD drive and it's mint, BUT IS IT GOOD?" you're just being silly Same goes for floppies, there are a million more reasons to doubt a floppy that's 20 years old and spent its life in the attic than an unopened pack of DD disks

Adapting an A600 drive to another model, well. Maybe it's easy as pie, maybe not - haven't tried. My A600 works fine and dandy, but I still got a spare new one, because it must be obvious to anyone that at least the drives will vanish lickety-split.

[dansalvato]

Originally Posted by TheCyberDruid

Screened? Not sure about that, but if a checksum error is known, it's mentioned in the TOSEC name (e.g. Ashes of Empire (1992)(Mirage)(Disk 1 of 3)(Program)[cr FSN][b checksum error]). Maybe you use this disk image Haxxy : Prince of Persia v1.0 (1991)(Domark)[cr Angels][f AGA SKR][t +2 Angels][b errdms] (CRC32 : 8FCF2156) ?

The Amiga 1000 isn't compatible with AGA, is it? =(
I'll try anyway, though.

[TCD]

Sorry, might have been confusing. I meant that the image you're using is this one and that is why you have the problem. Reading the other thread I guess it's really a problem with the cracked version of PoP itself.

[mr.vince]

fell free to send me the questionable image and i'll try writing it back with the c20 alpha. if it works on the amiga, then there is something wrong with your machine which needs fixing. i assume i will get the same error here...

[rkauer]

Originally Posted by mr.vince

<SNIP>

Hmmm... from what I know bias and recording current are adapted when writing to a DD disk with an HD drive. But... I am sure HD drives are optimized for HD disks, not DD disks. Anyway, do you have more information on this or did you gather this from experience?

The really bad thing is all this happens in the drive logic before any controller can do anything about it. I know there are quite some differences between makers and models.

From experience I can tell HD drivers don't handle DD disks correctly. The heads are narrow than the DD ones, making the magnetized area narrower than desirable.

That's why DD disks written with HD drivers last much less than ones written on original drivers.

[prowler]

Originally Posted by rkauer

From experience I can tell HD drivers don't handle DD disks correctly. The heads are narrow than the DD ones, making the magnetized area narrower than desirable.

Also, the magnetic field is weaker, so the "imprint" is less deep.

Originally Posted by rkauer

That's why DD disks written with HD drivers last much less than ones written on original drivers.

It's a fact.

[mr.vince]

Originally Posted by rkauer

The heads are narrow than the DD ones, making the magnetized area narrower than desirable.

That's why DD disks written with HD drivers last much less than ones written on original drivers.

Originally Posted by prowler

Also, the magnetic field is weaker, so the "imprint" is less deep.

Hmmm...

1. The head being narrower should not be a problem. The disk is rotating, so the narrownes of the head should only be important for the smallest (=shortest) information you want to write, not the other way round. I mean, if you're writing cells with 2 us in size, you simply double the time you'd leave the head on as you'd do when writing a 1 us cell. The information should even be more precise, because a smaller head would mean that the flux change should be more accurate because of less overlap of magentic field. So this should not be an issue at all.

2. The strength of the field depends on the voltage that drives the coil. I assume that if made per spec, the current should be adjusted depending on the media type.


Nevertheless, I think you are right in regard to what you describe. I strongly assume that a) the quality of disk drives has suffered over the years because they had to become cheaper and cheaper b) makers in china and other places simply do not care about being DD compliant because no customer did ask for DD reading / writing.

I feel that older drives (NOS from the 90ies) usually work much better than recent ones.

Has anyone here equipment to measure magnetic fields on a disk surface?

[Photon]

If you have a HD drive, you should use HD disks. The lower power that HD drives use is not enough for the different media in the DD disks. If your computer (OS) doesn't support more than DD, it should have a DD drive and you should use DD disks. Putting the right components in is part of making a nice rig