Five and quarter drives

From: Eric Smith <eric_at_brouhaha.com>
Date: Fri Feb 11 18:26:18 2005

Tom Jennings wrote:
> It won't work if they microstep. I suppose that's possible, in
> which case a 96tpi drive would look like a 48.

I'm not talking about microstepping. In theory a floppy drive could
do that, and I've even considered trying to hack a 1.2M drive (96 TPI)
to use microstepping to read 62.5 TPI disks. But I doubt that any real
floppy drive ever did that, because it would be ridiculously expensive.

I'm talking about the drive electronics doing double-stepping. One
step pulse from the host interface turns into two steps of the
motor.

Note that I'm *not* trying to describe host-implemented double-
stepping, used to read 48 TPI disks in a 96 TPI drive, though the
concept is similar.

> If 40 bumps leaves the head half way to the center, well there you go.

Unless the drive uses a stepper motor with 80 steps for the full
stroke, and the electronics does double-stepping.

Eric
Received on Fri Feb 11 2005 - 18:26:18 GMT