DOS feature on formatting disk

[Bjørn Vermo]

On Tue, 18 Jan 2005 09:35:01 -0800 (PST), Dwight K. Elvey  
<dwight.elvey at amd.com> wrote:

> Hi
>  DOS has an irritating feature when asked to format
> a disk. If track 0 is partially readable it will
> fail to format, even if you use the /u option.
> I've been moving data from one machine to another
> and the source machine has a flaky drive. It sometimes
> trashes track 0.
...

Any OS / file system has problems if track 0 is really bad, especially if  
sector 0 is bad.
I have been able to "fix" old IBM 10MB drives by adjusting the physical  
end stop by a fraction of a trackwidth.
On these drives, there is a small bumper on the outside that the external  
part of the actuator bumps against when you send the drive a command to  
recalibrate or locate to cylinder zero. Adding a very thin sliver of metal  
will move the calibration point by a fraction of a track. If you try this,  
you may be able to find a spot where you can successfully format the first  
cylinder.


-- 
Bjørn