Tarbell is making me insane

[Grant Stockly]

At 11:27 PM 11/13/2007, you wrote:
>On 13 Nov 2007 at 22:57, Grant Stockly wrote:
>
> > >FYI: 3.5" disks were never meant to run at 125khz.  The
> > >720k mode is 250khz and the 1.44mh is 500khz.  The read
> > >amps just may not work well down that low.
> >
> > Do you think that it would be better if I were to get the Tarbell to
> > run at 4MHz (250kHz)?
>
>Wait one darned second.   There's a lot of confusion here--many
>vendors refer to the *data rate*, not the actual clock.  Since the
>1771 is an FM-only chip, that translates to 2 cells per bit time, or
>a 250 KHz clock rate.  The frequency of the clock at pin 24 of the
>1771 should be 1MHz.  If it's 2MHz, it's running at the 8" rate
>(500KHz = data rate of 250KHz).

I'm sorry about that!  : )  Right now it has a 2MHz crystal to run 
the 1771 at 1MHz.  I forgot all about the divider...

Grant