"Low level format" is pretty much a relic of the old non-servo MFM
drives. I recall that early Maxtor IDE drives implemented a LLF
On Fri, 29 Sep 2017, Christian Corti via cctalk wrote:
Lowlevel formatting has to be done for *all* ST-506 interface drives (e.g.
"MFM" and "RLL" drives). It is the disk controller that needs to write its
sector and track layout to the drive (ID marks, data marks, GAPs, CRC, ECC
and so on). This is also true for SMD drives, for example. So it didn't
make much sense in selling preformatted drives until when disk drives
exposed only the disk blocks to the host. Whether a drives uses servo
information or not is irrelevant. I don't consider writing servo
information as lowlevel formatting.
You'd think so.
But, the exact same thing applied to floppy disks.
Formatting has to be done for *all* floppy disks. It is the disk
controller/FDC that needs to write its sector and track layout to the
drive (ID marks, data marks, GAPs, CRC, and so on.
Obviously, they would not be pre-formatted, since the format could be done
in multiple ways.
But, SOME manufacturers did not provide the user with a way to do that
format (DEC, etc.)
AND, once a SIGNIFICANT portion of the market had standardized on one
particular format, the floppy manufacturers started to sell them
pre-formatted. If you need a different format, then you can manually
reformat them yourself. (You can erase a PC formatted disk and RE-format
it for a few thousand other formats)
Similarly, when the majority of the market wanted IBM/WD1003 "AT"
drives, preformatting became feasible. "You can RE-format if it's not
what you wnat."
