DISK ERASE V2.1 - Utility for erasing any DEC Supported disk drive.

Author :	Jeff C. Cameron
		
		eMail : jcam90502@jcameron.com

	Abstract :

    This program is designed to write fixed and random patterns to each 
physical block of a disk drive on a OpenVMS system. This software will run 
on OpenVMS version 5.0 or higher. The user first mounts the disk device
with the /FOREIGN qualifier then runs the program. In the program, the
user first selects the disk device and then proceeds to write patterns
to it.

    The screen has four areas of interest. Menus are presented on the left
side, and disk information and writing status is presented on the right.
Below these areas are two reversed video regions. The first two lines
display instructions, and the last two lines present error messages, if
any occur.

    To use the menus, press the number of the menu item desired, or use
the up and down arrows to select the desired option. To execute the 
selected item, press return. Control-Z at any menu selection exits the
current menu returning to the previous one, or returns to DCL if entered
at the main menu.

    During writing operations, you can press Control-C or Control-Y to
interrupt the process, where you are presented with the choice to continue
or abort by pressing the letters C or A respectively.

    The operations include writing all ones, all zeros, random data, or a 
user specified 32 bit hex pattern (with or without auto-verify), and the 
ability to check any physical block on the disk.

    The DISK_ERASE program generates a logfile of all operations, and
success/failure messages. The output log file is written to the file
defined by the logical name DISKERASE. If there is no logical name defined
for the logfile the file will be DISKERASE.LOG in your current default
directory.

    This program was written to address a DOD requirement for classified 
sites to erase (declassify) disks by writing all ones, all zeros, a fixed 
pattern, and random data one or more times. It has been approved by DIS
for our site only, and would have to be approved by your DIS representative
prior to use at DOD or DOD contractor sites on classified disks.

	Notice :

    This software may not satisfy DOD requirements for RA8x and RA9x
 series disks, or any other disk that supports "Automatic Block Revectoring"
 or CIRTs (Controller Initiated Replacement Tables). Disks that use HIRTs
 (Host Initiated Replacement Tables) are supported. The reason for this is
 that DISKERASE can only access Physical Blocks as seen by the QIO system 
 service.

	Warning :

    Running this program on your disks destroys all of your data and disk
structure, so use it carefully. Depending on the manufacturer of the disk
drive, you may have to re-run the BAD block locator utility prior to
re-initialization of the disk, via the DCL command $ ANALYZE/MEDIA. See the
VMS utility manual for the $ ANALYZE/MEDIA command for details.

	Credits :

    Thanks to Glenn Martin for his modifications to increase the buffer size 
to enable full track reads and writes which improved performance consider-
ably.

	Compiling and Linking :

    This program source file contains all of the FORTRAN code necessary to 
compile and link the executable image. The source should be compiled with
the /EXTEND qualifier because some source lines extend beyond column 72.

    Place the source file in the desired directory, and set your default to
that directory, then enter in these commands :

		$FORTRAN/EXTEND DISK_ERASE
		$LINK DISK_ERASE

    Once this is done, you can run the DISK_ERASE program by entering :

		$MOUNT/FOREIGN disk_device
		$RUN DISK_ERASE

	Usage :

    This program uses the OpenVMS screen management facility to provide 
various a menus, so it is recommended that it be run from a VT100 or 
compatible video terminal. The display screen is divided into three major
sections. The left side contains the menu of the various options you may 
perform. The right side of the screen contains information on the disk, and
current status of the erasing procedure. The bottom of the screen contains
error messages, and instructions.

    In the menu window, there will be many selections, one of which is high-
lighted. Pressing the RETURN key will execute the highlighted item. The UP
and DOWN arrow keys will change the current highlighted selection (you may
also press the single digit key of the menu item you wish). A control-Z 
will exit the current menu and return to the previous menu, or back to DCL 
if you are at the top main menu.

    This program supports all disk drives sanctioned by Digital as being
known disk types (See notice above). Prior to running this program, the 
desired disk must be online and mounted foreign to the running process. In 
addition, the running process must have PHYSICAL I/O privileges to the 
desired disk device.

    If you have any questions, please feel free to contact me at the above
address or phone/fax number. NOW GO ERASE THAT DATA!