Re: No HDs on my //e?

[nathan@cco.caltech.edu (Nathan Mates)]

In article <37mn1f$9uu@usenet.INS.CWRU.Edu>,
John L. Graham <fl332@cleveland.Freenet.Edu> wrote:

>Hmmm, sounds like the disks are hard sectored for MS-DOS. Soft
>sectored disks can be reformatted, but hard sectored disks are
>fixed.

   No. Hard sectoring refers to disk sectors synchronized by the
physical media. The drive uses the small synchronization hole (the
little circle slightly below center and right of the main hole for the
drive to spin the disk). When a light source can pass through it, the
drive knows exactly where it is radially, and can find sectors by
tracking how far it's rotated. The actual media of the disk in the
region of where data is written to has no changes from a soft-sectored
disk; it's just a magnetic surface than is written to.

   Soft sectoring is the use of what's written to disk to determine
where it is. By use of synchronization bytes and the like, the
system determines which sector is which, and thus knows where it
is. (That's why Apple 5.25" disks clatter on booting-- the drive
head is simply moved enough times to guarantee that it'll be over
track 0 no matter where it started from; there is no way for the
system to know that it's reached the end, and can stop trying to
move it). With soft-sectoring, all sorts of copy-protection fun
can be realized that would be almost impossible with a hard-sectored
disk.

   Bottom line: the media's the same for both disks, but the
difference is whether _hard_ware or _soft_ware determines where things
are.

Nathan Mates



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