J. Vernet wrote:
As I remember, it's not a drive harware issue but a controler hardware
issue... In an USB external floppy, there is an USB controler that do
not let the drive being used in 800k (variable rotation speed).
It's very likely that the drive can't spin at more than one speed, that the
motor is fixed.
As far as I know, only Apple computers had variable-speed 3.5" floppy
drives. These were manufactured by Sony.
The Apple drives used GCR at their lowest level, whereas the IBM drives used
MFM.