Date : Wed, 26 Oct 2005 15:15:48 +0100
From : Paul J <peterbilt@...>
Subject: BBC using 3.5 high density format
Has anyone had a go at getting a 3.5 high density drive working at high
density capacity ?
I found some interesting notes on an atari site, the atari st uses an
'ajax' floppy controller that supports double density, high density, and
extended density floppys. The controller is a direct pin-pin replacement fo
r
the WD 1772 controller. To switch to high density formats Pin 18 needs a
16mhz clock frequency, instead of the normal 8mhz for double density disks.
Could either hard wire a manual switch to a clock generator, to change
densities; or wire the hd detect microswitch in the drive to the controller
through the drive cable.
Would need a customised ADFS rom capable to driving the high density
format.
Just wonderred if anyone has had a go at this,
Regards,
Paul.
<div>Has anyone had a go@... a 3.5 high density drive working a
t high density capacity ?</div>
<div> </div>
<div>I found some interesting notes on an atari site, the atari st uses an
'ajax' floppy controller that supports double density, high density, and ex
tended density floppys. The controller is a direct pin-pin replacement for
the WD 1772 controller. To switch to high density formats Pi
n 18 needs a 16mhz clock frequency, instead of the normal 8mhz for double d
ensity disks.
</div>
<div> </div>
<div>Could either hard wire a manual switch to a clock generator, to change
densities; or wire the hd detect microswitch in the drive to the controlle
r through the drive cable. </div>
<div> </div>
<div>Would need a customised ADFS rom capable to driving the high dens
ity format.</div>
<div> </div>
<div>Just wonderred if anyone has had a go@...,</div>
<div> </div>
<div>Regards,</div>
<div>Paul.</div>