Datadrainer wrote on 2021-11-16, 21:00:
For what I remember of the 80's, low level format was used for MFM media (HDD, floppies). Used at the time to restore bad sectors or to allow a disk to work with a new controller. If a long format in IomegaWare is a LLF it means a bad ZIP cartridge, like a bad floppy disk, can potentially be recovered that way.
Yes and no. You can't do the same as with MFM LLF on Floppy and old stepper motor head driven HDDs, as ZIP heads are Voice Coil driven, thus the disk media is hard servo-tracked on factory time (you can't alter it with your home ZIP device). But certainly it does more than the OS formatting built in procedures... As I said, in the same level you can accomplish with manufacturer supplied tools and stuff like the AceLabs PC3000 on modern HDDs.
I imagine it invokes a firmware factory test routine stored in the ZIP device firmware, or uploads one stored in the Iomegaware executable to the ZIP reader via manufacturer specific ATAPI CBDs, and executes it there. That procedure does test to the surface sectors, updates the GS tables stored in the ZIPs SA cylinder with any new bad sector found, and while modifying the SA, it also resets the security data stored there. You know, the same stuff you can do with the easy mode of PC3000 software, or things like SeaTools/MaxBlast/MHDD/HDAT2/etc.