Got to love Mac 800k GCR disks
Archiving Mac 400/800k CGR disks is just so much fun. Almost every single time I have to archive a set, I wind up swapping through my pile of 3.5" drives just to find one that will read it them.
So I had two different disk sets. The first set gave me errors on the outer tracks using my usual Teac drive, so swapped out for the Toshiba. Worked perfectly, no errors. Tried the second set in the Toshiba since I had it out - errors on the outer tracks. Swap back to the Teac, worked perfectly, no errors.
The Kryoflux shows the entire outer tracks as evenly "noisy" on both sets. So these tracks are only just marginally readable, given the analog filtering properties of each drive. The Toshiba and Teac drives are the best when it comes to reading variable bitrate GCR encoding, which still shows how hard it is to use PC drives to read GCR which already has weird timings compared to FM/MFM, while VBR outer tracks are scrunched in there at a bitrate much higher than the normal 250kbs.
So I had two different disk sets. The first set gave me errors on the outer tracks using my usual Teac drive, so swapped out for the Toshiba. Worked perfectly, no errors. Tried the second set in the Toshiba since I had it out - errors on the outer tracks. Swap back to the Teac, worked perfectly, no errors.
The Kryoflux shows the entire outer tracks as evenly "noisy" on both sets. So these tracks are only just marginally readable, given the analog filtering properties of each drive. The Toshiba and Teac drives are the best when it comes to reading variable bitrate GCR encoding, which still shows how hard it is to use PC drives to read GCR which already has weird timings compared to FM/MFM, while VBR outer tracks are scrunched in there at a bitrate much higher than the normal 250kbs.