Floppy drive pin 2 question?

[Jules Richardson]

Just futzing around with this Manta board (SCSI floppy controller).

 The docs I have say that pin 2 of the floppy connector is normally an
input to the controller from the drive, but that some drives expect pin
2 to be an output to the drive from the controller (e.g. for changing
rotation speed on a drive capable of 300 and 360rpm)

That sounds wrong to me; surely most drives either don't use pin 2 for
anything, or they expect it to be an output from the controller (to cope
with things like speed changes)

What drives use it as a signal driven by the drive, and what for? 

I'm tempted to ignore the docs I have and configure it as an output from
the controller - I'd just rather not blow up a drive or controller
board :-)

cheers

Jules