Formatting a fresh floppy...

[Syntho]

Some of the fresh floppy diskettes I have come up with a 'PC' icon on them. Is that a different format from the regular DOS format?

I just blew through about 6-7 of these floppies, trying to format them to DOS format in System 7, but every single one of them gives me an error that says "the disk could not be erased because it is defective"

 

[tanuki65]

PC icon = DOS format. Your disks may be erratic though. Try getting some sealed-in-the-box 3M DS,HD disks. Those work for me. Where did you get your disks?

 

[Syntho]

I got two packs of these sealed Verbatim diskettes but they all fail for some reason. I did notice that these are probably old since there's fading on every diskette in a circular pattern. I've noticed that a lot but never knew exactly why that happens.

 

[Elfen]

The problem might be the floppy drive. Try formatting them on a PC.

Also, inspect the surface of the disk by sliding the door to the side and look at the media with a bright light. It should be smooth and uniform if new or near new condition. It should look like it has rings if it is old and been used regularly. But specks of dark, surface bubbles, and surface peeling are signs of a bad disk.

 

[Charlieman]

Disk Charmer by Fabrizio Oddone is a handy utility for formatting floppies and manipulating disk images. In my experience, it was effective at formatting good disks that had been formatted for the PC but which the Finder disliked. The versions for classic Mac OS were distributed via the Umich archive and should be easy to find.

 

[Gorgonops]

If you have a powerful magnet lying around (I use a rare earth one pulled out of some piece of junked machinery) you can try "swirling" it around the disk a few times. I've been doing this to used 1.44mb disks that I'm formatting to 400/800k for my Mac 512k and Apple IIgs; I find the disks almost always fail to format with the PC format present, because the write head current of the lower density drives can't overwrite it, but doing the scrambling thing with the magnet lets them work about 80-90% of the time.

(I'm totally aware it's not really kosher to use the HD disks for DD formats, but I'm just using them to slap games and such on so it's not a major tragedy if one fails; just need to reimage it.)

 

[Charlieman]

A colleague phoned me at work to tell me that he'd copied some files to a floppy disk. The student who owned the disk would pop along shortly for assistance of some kind. My colleague wasn't daft and knew how to copy files.

The student turned up, opened out his pockets and dropped the floppy disk. The disk fell four feet onto a carpeted floor.

I inserted the floppy disk into my Mac, but the disk was garbage. It had lost all of the data and all of its formatting. Dropping the disk had wiped its contents.

Brown particles on plastic media can provide reliable storage media or a disaster in waiting. And the medium is so contrary. I sort of believe that Gorgonops' solution might work for floppy disks. I'm eyeing some magnets retrieved from a hard disk head. But I know people who used a magnetic bulk eraser (designed for tape media) on Zip and Jaz cartridges which never worked again.

A quick query for Syntho: Have you tried writing disk images to those floppies? Using different image copiers?

 

[Gorgonops]

And the medium is so contrary. I sort of believe that Gorgonops' solution might work for floppy disks. I'm eyeing some magnets retrieved from a hard disk head. But I know people who used a magnetic bulk eraser (designed for tape media) on Zip and Jaz cartridges which never worked again.

I think both Zip and Jaz have embedded servo positioning information encoded magnetically on the disk. (Remember, they're sort of floppy/hard disk hybrids.) It generally takes special equipment to write said info, the drives can't do it, so, yeah, not surprised at all that using a bulk eraser would kill those. Floppies don't have that problem.

We used to have lying around the office a really scary machine designed to wipe hard disks magnetically; it came with warnings about leaving unsecured objects close to it, and drives coming off it would be warm to the touch following the ordeal. Drives erased with that thing were likewise *permanently* destroyed.

 

[raoulduke]

I've noticed a similar or the same error and have an anecdotal partial solution in a limited number of cases - can you restore whole (Mac) disk image to the disks that otherwise fail to format?  It may be more successful to try doing this from WinImage on a PC if that's an option and depending on what type of disks we're talking about.  (This solution is irrelevant if there's a catastrophic physical problem though)

 

[Gorgonops]

I think both Zip and Jaz have embedded servo positioning information encoded magnetically on the disk.

Yep, a buk eraser will murder a ZIP disk. Don't try it at home, kids.

 

[Syntho]

Turns out both batches of those disks I bought were bad. I got another batch and the first two formatted perfectly

Out of curiosity, what's with all that fading on these diskettes? I have some 'original' floppies of software and none of those have that weird circular fading and discoloration on them.

 

[Elfen]

Depending on the disk, the ferrious oxide is eroding from the disk's surface as the head of the drive scrapes it off over time. Some disks have an oil on them to prevent this as much as possible but it does not last forever and by now a 20 year old disk would have that oil rancid.