UH2@PSUVM.BITNET (Lee Sailer) (12/10/89)
I have a floppy that works fine in df0:, but is df1:BAD in df1: I made
a copy, and tried to reformat it. Oddly, it formats fine in df0:,
but has a bad key when it is in df1:
This strikes me as bizarre. I have many, many other disks that work fine
in both df0: and df1:. Why does this one disk fail in df1:?
leeckp@grebyn.com (Checkpoint Technologies) (12/11/89)
In article <89343.132335UH2@PSUVM.BITNET> UH2@PSUVM.BITNET (Lee Sailer) writes: >I have a floppy that works fine in df0:, but is df1:BAD in df1: I made... Try checking your rotational speed. Marauder II (if you have a copy) will do it. If your two drives have sufficiently different rotational speeds, a floppy created on one might not work on the other. Make sure you format new floppies on the drive that has the SLOWER rotational speed.
Doug_B_Erdely@cup.portal.com (12/11/89)
Sounds like the disk could be right on the border line between a good disk and a bad disk. The small differences between drives would explain why one drive could format and use it, while another drive would spit up on it. - Doug - Doug_B_Erdely@Cup.Portal.Com
bleys@tronsbox.UUCP (Bill Cavanaugh) (12/11/89)
The first thing you want to do is check the drive alignment in >>both<< drives.
tjf@lanl.gov (Tom J Farish) (12/12/89)
How bout this one? When I get a bad (unformatable) disk I just pop it into a mac at work and format it. Sometimes it formats, sometimes not. But when I take it back home.... it formats in the Ami! I've had most trouble with disks chomped on by AMAX getting a bad sector. Shove 'em into the Mac...that'l teach 'em.
ccplumb@rose.waterloo.edu (Colin Plumb) (12/12/89)
In article <89343.132335UH2@PSUVM.BITNET> UH2@PSUVM.BITNET (Lee Sailer) writes: >I have a floppy that works fine in df0:, but is df1:BAD in df1: I made... This is a sign of something with one of the drives being out of whack. It may be rotational speed, and that's easy to check, but could also be head alignment, and that needs a repair shop. (To be precise, an alignment floppy and an oscilliscope.) In article <14087@grebyn.com> ckp@grebyn.UUCP (Checkpoint Technologies) writes: >Try checking your rotational speed. Marauder II (if you have a copy) >will do it. If your two drives have sufficiently different rotational >speeds, a floppy created on one might not work on the other. Make sure >you format new floppies on the drive that has the SLOWER rotational >speed. You've been playing with IBM disk formats too long! On the Amiga, this doesn't matter, as it does the equivalent of a format on every track as it's written. There's a utility caled xcopy (nothing to do with the 1.3 default alias) that gives some useful information about the errors it finds. There are probably others. -- -Colin
fgd3@jc3b21.UUCP (Fabbian G. Dufoe) (12/13/89)
From article <38586@lanl.gov>, by tjf@lanl.gov (Tom J Farish): > > How bout this one? When I get a bad (unformatable) disk > I just pop it into a mac at work and format it. Sometimes > it formats, sometimes not. But when I take it back home.... > it formats in the Ami! I've had most trouble with disks > chomped on by AMAX getting a bad sector. Shove 'em into > the Mac...that'l teach 'em. A trick that I've used successfully with disks that wouldn't format clean is to pass them over a bulk tape eraser. That seems to erase more from the disk than the format command does. I guess the disk drive doesn't have nearly as high a level as the bulk eraser. --Fabbian Dufoe 350 Ling-A-Mor Terrace South St. Petersburg, Florida 33705 813-823-2350 UUCP: ...uunet!pdn!jc3b21!fgd3
dougp@voodoo.ucsb.edu (12/14/89)
-Message-Text-Follows- In article <814@jc3b21.UUCP>, fgd3@jc3b21.UUCP (Fabbian G. Dufoe) writes... > A trick that I've used successfully with disks that wouldn't format >clean is to pass them over a bulk tape eraser. That seems to erase more >from the disk than the format command does. I guess the disk drive doesn't >have nearly as high a level as the bulk eraser. > >--Fabbian Dufoe Format will only clean up the actual tracks, if there is spurious data inbetween tracks, this can show up in the read signal and cause problems this can occure if the disk was not erased after it was certified by the manufacturer. The bulk eraser works because it erases the entire disk, not just the tracks that the head actualy moves to. Douglas Peale.
mamba@csd4.csd.uwm.edu (Paul A Deisinger) (12/14/89)
In article <3309@hub.UUCP> dougp@voodoo.ucsb.edu writes: >-Message-Text-Follows- >In article <814@jc3b21.UUCP>, fgd3@jc3b21.UUCP (Fabbian G. Dufoe) writes... >> A trick that I've used successfully with disks that wouldn't format >>clean is to pass them over a bulk tape eraser. That seems to erase more >>from the disk than the format command does. I guess the disk drive doesn't >>have nearly as high a level as the bulk eraser. >Format will only clean up the actual tracks, if there is spurious data >inbetween tracks, this can show up in the read signal and cause problems >this can occure if the disk was not erased after it was certified by >the manufacturer. The bulk eraser works because it erases the entire >disk, not just the tracks that the head actualy moves to. Wouldn't this have the sideaffect of magnetizing the metal hub and shutter on the disk? This would be *very* bad I would think. Putting magnetic things near diskettes and any computer equipment is somthing I have always reguarded as a Big NONO. Perhaps the bulk eraser you use is not strong enough to magnetise the hub? The eraser I have is quite old, and goes back to being used on reel-to-reel tapes, I can pick up a three pound weight with it.... think a more modern one would work out ok on diskettes? (I have about 25 diskettes that have become "trashed", these are disks that once were fine but now will not validate after formatting). -- Paul Deisinger "Me wa kuchi hodo ni mono o ii" Joe Pantuso "Bushi wa kuwanedo takayooji" mamba@csd4.csd.uwm.edu<-- easy to reach and read every day. joe@lakesys.lakesys.com<-- only get's read every week or two.
sjm@sun.acs.udel.edu (Steve Morris) (12/16/89)
In article <1487@uwm.edu> mamba@csd4.csd.uwm.edu (Paul A Deisinger) writes: >>In article <814@jc3b21.UUCP>, fgd3@jc3b21.UUCP (Fabbian G. Dufoe) writes... >>> A trick that I've used successfully with disks that wouldn't format >>>clean is to pass them over a bulk tape eraser. That seems to erase more > >Wouldn't this have the sideaffect of magnetizing the metal hub and shutter >on the disk? This would be *very* bad I would think. > NO! if the process is done correctly. A bulk eraser is designed to restore the tape to it's >UN<magnetized state. It will therefore do the same to the metal parts of the disk case. In fact I have used one to demagnetize a screwdriver. A bulk eraser generates an alternating magnetic field. If an object is removed from the field slowly, the magnetic particles will tend to align in a random order, ie an unmagnetized state. If, however, the field is removed suddenly, the object will be magnetized in the direction of the field before it's removal. This can be used to create a magnetized screwdriver if needed. -Steve
stan@teroach.UUCP (Stan Fisher) (12/16/89)
In article <1487@uwm.edu> mamba@csd4.csd.uwm.edu (Paul A Deisinger) writes: >In article <3309@hub.UUCP> dougp@voodoo.ucsb.edu writes: >>-Message-Text-Follows- >>In article <814@jc3b21.UUCP>, fgd3@jc3b21.UUCP (Fabbian G. Dufoe) writes... >>> A trick that I've used successfully with disks that wouldn't format >>>clean is to pass them over a bulk tape eraser. That seems to erase more *stuff deleted* > >Wouldn't this have the sideaffect of magnetizing the metal hub and shutter >on the disk? This would be *very* bad I would think. *stuff deleted* >-- > Paul Deisinger "Me wa kuchi hodo ni mono o ii" > Joe Pantuso "Bushi wa kuwanedo takayooji" > mamba@csd4.csd.uwm.edu<-- easy to reach and read every day. > joe@lakesys.lakesys.com<-- only get's read every week or two. Nope. Degausers (demagnetizers) are AC electromagnets not DC. It takes a DC electromagnet to generate a field that magnetizes. If used properly, an AC electromagnet by having its poles swap at 60HZ scrambles the polarity of any ferrous (sp?) materials thereby demagnetizing or eraseing the disk. By saying "if used properly" I refer to the method of slowly pulling the degauser away from the tape/disk until the object is out of the field to ensure the object doesn't get magnetized to some more uniform polarity if the field were abruplty withdrawn. This may not be the most technically accurate description, but I think it's adequate? Stan Fisher - stan@teroach.phx.mcd.mot.com - asuvax!mcdphx!teroach!stan Motorola Microcomputer Division, Tempe, Arizona - Voice (602) 438-3228 Call our User Group BBS "M.E.C.C.A." running Atredes 1.1 @ (602) 893-0804
fgd3@jc3b21.UUCP (Fabbian G. Dufoe) (12/16/89)
From article <1487@uwm.edu>, by mamba@csd4.csd.uwm.edu (Paul A Deisinger): > Wouldn't this have the sideaffect of magnetizing the metal hub and shutter > on the disk? This would be *very* bad I would think. No, it doesn't magnetize the metal hub and shutter on the disk. Remember a bulk tape eraser is an electromagnet running off alternating current. Consequently, the polarity of its magnetic field is reversed sixty times a second. As a result, properly used, it will demagnetize objects on which it is used. The proper procedure is to place the disk on the eraser (or hold the eraser over the disk, depending on how your eraser is designed). Then switch it on and move the disk relative to the eraser so all then magnetic surface has been well exposed to the magnetic field. Next, move the disk away from the eraser. When the disk and eraser are about three feet apart, switch off the eraser. --Fabbian Dufoe 350 Ling-A-Mor Terrace South St. Petersburg, Florida 33705 813-823-2350 UUCP: ...uunet!pdn!jc3b21!fgd3
phorgan@cup.portal.com (Patrick John Horgan) (12/17/89)
>Wouldn't this have the sideaffect of magnetizing the metal hub and shutter >on the disk? This would be *very* bad I would think. >-- > Paul Deisinger "Me wa kuchi hodo ni mono o ii" > Joe Pantuso "Bushi wa kuwanedo takayooji" > mamba@csd4.csd.uwm.edu<-- easy to reach and read every day. > joe@lakesys.lakesys.com<-- only get's read every week or two. Nope! Remove the disks from the vicinity of the eraser while the power's still on...it won't leave any residual magnetism in the metal hub or shutter. Patrick Horgan (phorgan@cup.portal.com)
GORRIEDE@UREGINA1.BITNET (Dennis Robert Gorrie) (12/18/89)
Bulk erasers and demagnitizers also have other uses. I once placed a very powerful speaker right beside my Amiga monitor. Low and behold, the screen turned from orange to blue. I used a demagnitizer to degauss the screen, and fixed the colors. P.S. Please don't try this at home folks. For some monitors, you can realy mess up the colors, and may take a LONG time to degauss it. +-----------------------------------------------------------------------+ |Dennis Gorrie 'Sudden de-compression Sucks!' | |GORRIEDE AT UREGINA1.BITNET | +-----------------------------------------------------------------------+
richard@gryphon.COM (Richard Sexton) (12/23/89)
>>>> A trick that I've used successfully with disks that wouldn't format >>>>clean is to pass them over a bulk tape eraser. That seems to erase more >*stuff deleted* >> >>Wouldn't this have the sideaffect of magnetizing the metal hub and shutter >>on the disk? This would be *very* bad I would think. >*stuff deleted* > >Nope. Degausers (demagnetizers) are AC electromagnets not DC. It takes a >DC electromagnet to generate a field that magnetizes. If used properly, an >AC electromagnet by having its poles swap at 60HZ scrambles the polarity of >any ferrous (sp?) materials thereby demagnetizing or eraseing the disk. By >saying "if used properly" I refer to the method of slowly pulling the >degauser away from the tape/disk until the object is out of the field to >ensure the object doesn't get magnetized to some more uniform polarity if the >field were abruplty withdrawn. This may not be the most technically >accurate description, but I think it's adequate? Umm, aren't they stainless steel ?