LLFCLR.TXT

last update by Roedy Green 1993 June 8

WARNING
*******

LLFCLR is one of the most dangerous utilities ever written.
READ ALL THE DOCUMENTATION FIRST BEFORE YOU USE IT!

Purpose
*******

LLFCLR gives you fresh slate to work with prior to doing a low
level format.  LLFCLR erases the first track of a hard disk.
This track contains the partition table and sometimes
proprietary low level formatting information.

How Do You Use It
*****************

LLFCLR C:
or
LLFCLR D:

It will then prompt you to ask if you really want to wipe out
your hard disk.  Answer Y for Yes.  Any other response will
abort.  For safety you must specify which physical drive you
want to clear, and you MUST use UPPER CASE both the specify the
drive and for the confirming Y.  These odd rules will help avoid
accidental use or use by curious monkeys.

Why Use It
**********

Sometimes a disk controller will behave one way with virgin hard
disk drives and another with drives it has formatted before.
You may find that even when you do a new low level format, there
may be residual effects from previous low level formattings.
LLFCLR clears out everything, giving you a fresh start.  The
catch is, as soon as you run LLFCLR, your entire hard disk is
effectively erased.

Spies might consider LLFCLR as a sort of cyanide pill for their
disks.  However very clever programmers will still be able to
fish some data off the disk using INT 13, even after LLFCLR is
run.  However, for all practical purposes, THE INSTANT YOU RUN
LLFCLR YOU HARD DISK IS GONE.  You must start either with a new
LLF or possibly (if you are lucky) just with a new FDISK and
FORMAT.

In particular, I wrote LLFCLR to get around a problem with
Speedstor.  If you accidentally use the "lock defects" option,
ever after the disk will steal 1K making your machine 639K
instead of 640K.  Even redoing the LLF will not help.  LLFCLR
prior to the LLF will clear the problem.

GETTING THE LATEST VERSION
**************************

Look for the latest version at my Web site:
  http://mindprod.com

Trouble Shooting
****************

> I tried LLFCLR and and it just gave me a general error message
> and chastisement for playing with it.  It didn't DO anything.

Please re-read the documentation.  There are several tricky
NON-OBVIOUS things you must do to make LLFCLR work.  You cannot
deduce these from the prompts.  I did this on purpose to make
LLFCLR harmless in a fool's hands.

> I used LLFCLR now all my files are gone, including LLFCLR!
> I can't even boot from my C: drive anymore.  I cannot even
> do a DIR C:

This is exactly what LLFCLR is supposed to do!  It clears the
decks for a new low level format which would also erase
everything.  Doesn't everybody know you need at least two
verified complete backups before you do an new low level format.

> I tried LLFCLR A: to erase a floppy diskette and force a reformat
> before it was used again.  It didn't work.

LLFLCR is designed to work on your two physical hard drives C: and
D: only, not floppies.

> I used LLFCLR C: to erase my C: drive, but it wiped out EVERYTHING
> the D: E: F: and G: partitions.

LLFCLR is works on PHYSICAL drives.  If you use it on your C: drive,
it wipes out all partitions on your first drive.  If you say
LLFCLR D: it will wipe out all partitions on your second
physical drive.

> I used LLFCLR D: to erase my D: drive, but it said "drive not
> responding."

For LLFCLR D: to have any meaning, you would have to have two
physical disk drives -- not just a D: partition on your C:
physical drive.

> I used LLFCLR C: on my XT drive.  Then I peeked with the Norton
> Utility Disk Editor to see what had happend to track 0.  I saw that
> though most of it had been zeroed, part of it had not.

Some Western Digital XT controllers hide disk geometry
information in the first sector on the disk.  The controller
BIOS takes special precautions to foil any attempts to erase it.
The BIOS successfully blocks LLFCLR from clearing that data.
The only practical way to get rid of it is to temporarily
install another brand of disk controller and do a low level
format with it.  When you work with these WD controllers, be
VERY careful when you specify the low level formatting
parameters.  If you get them wrong you may find it fiendishly
difficult ever to change your mind.

> LLFCLR sounds too scary for me.  I don't even want to try it.

If you use BootSave to a floppy BEFORE you use LLFCLEAR, you
will be able to undo the effects of LLFCLR by running BootRest
after booting from floppy.

GETTING THE LATEST VERSION

Look for the latest version at my Web site:
  http://mindprod.com

It would also be helpful if you mentioned the URL or source of where
you got your copy.  I want to make sure that site is kept kept up to
date.

Roedy Green
Canadian Mind Products
#101 - 2536 Wark Street
Victoria, BC Canada V8T 4G8
tel:(250) 361-9093
mailto:roedyg@mindprod.com
http://mindprod.com

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