Hi.

>
> At 03:36 AM 3/25/1998 Bill Cohane  wrote:
> >
> >This little debug program will completely clean off track 0 on your
> >hardisk.  Useful for removing drive BIOS overlays and such, and for
> >when drives don't seem to behave.  Will also completely remove track 0
> >viruses. . . . .
>
> Bill:
>
> And here I thought DEBUG users had gone the way of
> EDLIN.  <g>  The mini-assembler of Debug is nice but it
> is a dangerous tool in inexperienced hands. I'd recommend
> Norton's Programmer's Guide to the IBM PC for beginners.
>
> I'm not certain this would fully work because the DDO uses
> a hidden partition table and fools DOS into thinking everything
> is copacetic. I don't know the exact location of the DDO but it
> may not be where your script is doing its work. Afterwards,
> when you think all is well, the hidden table may be "resurrected"
> like the undead in a horror movie and there you go again.
>

        DEBUG is one forgotten but very useful program. I agree it
is dangerous, but it gives means to do low level things.
        What Bill suggested is physically writing bytes in the
proper places, and in a context where partition tables and DOS
units have no meaning. So the only thing that can fool it is if
INT 13H code has been modified; even if the disk is not properly
recognized it should work, since it writes to first physical sector.
I would be surprised if it wouldn't work.
        To not let INT 13H code to be intercepted, the best is to
boot from a DOS floppy, with no config/autoexec.

************************************
Javier Vizcaino. Ability Electronics. [log in to unmask]

Starting point:        (-1)^(-1) = -1
Applying logarithms: (-1)*ln(-1) = ln(-1)
Since ln(-1) <> 0, dividing:  -1 = 1
     (ln(-1) is complex, but exists)