Found the instruction to start Over!
 

Linux-based solution: now to see if this is Debian code?
If you can still somehow fire up Linux - say, via Tom's Root-Boot floppy - you can simply
invoke "dd", like so: dd if=/dev/zero of=/dev/hda bs=512 count=1
Yep, that's it. That MBR is gone. Obviously, you have to be root to do this. < not mine just cut what I needed.

DOS-based solution: I have this somewhere from EET 105

Boot with a DOS floppy that has "debug" on it; run "debug". At the '-' prompt, "block-fill" a 512-byte chunk of memory with zeroes:

f 9000:0 200 0

Start assembly mode with the 'a' command, and enter the following code:

mov dx,9000
mov es,dx
xor bx,bx
mov cx,0001
mov dx,0080
mov ax,0301
int 13
int 20

Press <Enter> to exit assembly mode, take a deep breath - and press "g" to execute, then "q" to quit "debug". Your HD is now in a virgin state, and ready for partitioning and installation.

Obviously, you have to be root... oh, oops. Anybody that walks up with a DOS floppy can do this to your system in about a minute, including boot time. Let's see; where was that article about securing your box, again?...

Hi,

Welcome to LQ!

Your point?

Constructive how?

You may want to reread LQ Rules.

:hattip:

I dunno... Other than lack of an explanation of why and when a person would want to do this (you want to wipe your MBR out why?), and maybe a note about, "Don't try this just to see what it does", I believe the information is potentially useful.. A better title more descriptive of what the thread's about wouldn't hurt either..

Hi,

Welcome to the forum. Thanks for the info even though I don't envision needing it.