Release Notes; Controller; Disk Image Overwrite - Xerox 850DP - Phaser Color Solid Ink Printer Release Note

8 Release Notes

The following information supplements the 10.X customer user guides.

8.1 Controller

8.1.1 Disk Image Overwrite

8.1.1.1 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.
8.1.1.2 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.
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