All in One Printer User Manual

Disk Image Overwrite

Overview

The Disk Image Overwrite feature has two operations: Immediate and On Demand. The immediate operation

overwrites image data on the hard drive immediately after it is no longer needed (i.e. When the page has printed).

The On Demand operation cleans the entire disk. Both On Demand Image Overwrite and Immediate Image

overwrite feature are configured by the system administrator, assuming that the system administrator password

is set to a non-zero value.

Algorithm

The overwrite algorithm for both IIO and ODIO conforms to the U.S. Department of Defense Directive 5200.28-M

(Section 7, Part 2, paragraph 7-202), and is common to all WorkCentre/WorkCentre Pros and Accxes controllers.

The algorithm for the Image Overwrite feature is:

Step 1: Pattern #1 is written to the sectors containing temporary files (IIO) or to the entire spooling area of the

disk (ODIO). (hex value 0x35 (ASCII “5”)).

Step 2: Pattern #2 is written to the sectors containing temporary files (IIO) or to the entire spooling area of the

disk (ODIO). (hex value 0xCA (ASCII compliment of 5)).

Step 3: Pattern #3 is written to the sectors containing temporary files (IIO) or to the entire spooling area of the

disk (ODIO). (hex value 0x97 (ASCII “ú”)).

Step 4: 10% of the overwritten area is sampled to ensure Pattern #3 was properly written. The 10% sampling is

accomplished by sampling a random 10% of the overwritten area.

See Online Help in Web Printer Management Tool for more details about using the Image Overwrite feature.