zwsdotcom@gmail.com wrote:
On Aug 27, 8:33 am, schmidtd <schmi...@my-deja.com> wrote:
(snip)
As far as I'm aware, HD 3.5" mechanisms of all flavors (Mac, PC and other) _ALL_ use the HD hole to sense HD media and change the spindle motor speed - 300rpm for DD and 360rpm for HD. So you MUST match the presence or absence of a hole to the media formatting, otherwise an HD drive won't read it.
HD 3.5in run at 300RPM(*). It is HD 5.25in that run at 360RPM, and most do that even when reading/writing DD disks (at 300kb/s). (*) That is why they have 18 sectors/track instead of 15 for HD 5.25in. -- glen