Re: Question about modifying DOS 3.3 or ProDOS

["Michael J. Mahon" <mjmahon@aol.com>]

Jayson Smith wrote:
> On a somewhat related topic, I've always hated the way DOS 3.3 goes 
> "BZZZZZZZZZZZ!" when recalibrating the drive after a read/write error. Is 
> there any way to shorten the time DOS moves the head toward track 0, so as 
> to possibly eliminate the buzzing in some circumstances? I much prefer the 
> way ProDos does this, going back a few tracks instead of making absolutely 
> sure the head is at track 0, and probably going way too far overboard in 
> most situations.
> Jayson

It doesn't go that much "overboard", since the seek cam _could_ be
up around "track 40" and you have to seek back far enough to hit
the track 0 stop.

Of course, you could always seek back until you found a track/sector
mark that you could read, then go again from there.

It would be possible to make a full recalibrate quieter, by half- 
stepping or even micro-stepping back against the stop, but it would
take more code space.

But it really doesn't matter.  The drive is absolutely not injured in
any way by repeatedly stepping back beyond track 0.  If you don't like
the noise, get a half-height drive with a quieter stop or a track 0
switch that disables backward seeks.  ;-)

-michael

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