Glen wrote:
BTW my understanding is that all 5.25 diskettes made
today are bin-sorted --
that is, they shoot for DSHD and the fallouts are sold as DSDD.
I don't believe that for an instant.
High-density requires a different, higher-coercivity coating, which will
not work properly for low density (single or double).
However, there's no difference between double density 40 track and 80 track
disks. They aren't even binned; they just get labelled differently.