There are two sets of kryofluxed floppies on archive.org. the 800k image is 58Mb, and all four floppies have errors at 60~65%. All the data is extractable except for the bad regions so... It looks like they kryofluxed the disks to preserve what data they had left, but it's not a solution. It's a huge waste of space, can you imagine a box of disks all inflated to 73 times their size?
Apple got Sony to make cav drives, (MacIIx and SE HD to the 9600 )and when they raised the price, no floppy. Sneaker net was over until USB drives became cheap.
One disk on archive that is unrecoverable is Adobe Type Manager. The areas where the fonts are is corrupted, but the data is available elsewhere, but the program isn't.
Now it sits in the cloud ( someone else's hard disk ) in a corrupted state. Wish I had an SE 30 to restore the disk, and put it's compressed image up as a replacement.
It says 800k/400k, but all his images are 800k. The filesystem may be different, but for diskcopy 4.2, it never made a difference. ( MFS vs hfs ). I am sure that for kryoflux, it does not make a difference either.
It does not show how kryoflux assists in recovery. They can be archived, and preserved, but not recovered. ( Just try the 800k ATM disk on archive.org )
The easiest solution is get a late model vintage mac that still has a floppy drive. the late model drives can read pretty much all mac floppies. the machine will be able to image the disk and copy it to usb(pci usb card) or over a network.
Or you can get something like a Greaseweazle[1] and go that route if you want to do more advanced extraction.
As far as I recall, none of the USB drives of the iMac era could read 400/800K GCR disks, they were PC drives that could only use 720/1440K disks. The Imation SuperDisk drives could also use their own 120MB “floptical” disis. Later versions extended it to 240MB, and could also write 32MB to a standard floppy disk.
MFS refers to the file system used on 400K disks. 800K disks used HFS.
It's a external USB attached floppy drive controller that uses a normal PC floppy drive.
It reads the raw disk stream and software then decodes that for whatever disk format it was. It seems old Mac disks can be recovered with it:
https://www.kryoflux.com/?page=home http://forum.kryoflux.com/viewtopic.php?t=135