Tarbell is making me insane
grant at stockly.com
Wed Nov 14 02:52:19 CST 2007
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...
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