IBM DTTA-351010 - Deskstar 10.1 GB Hard Drive Specifications page 141

Identifier Zero indicates that the device should check the supplied password against the user
password stored internally. One indicates that the device should check the given pass-
word against the master password stored internally.
The Security Erase Unit command erases all user data and disables the security mode feature (device lock
function). So after completing this command, all user data will be initialized to zero with write operation.
At this time, it is not verified with read operation whether the sector of data is initialized correctly. Also, the
defective sector information and the reassigned sector information for the device are not updated. The secu-
rity erase prepare command should be completed immediately prior to the Security Erase Unit command. If
the device receives a Security Erase Unit command without a prior Security Erase Prepare command the
device aborts the security erase unit command.
This command disables the security mode feature (device lock function), however the master password is still
stored internally within the device and may be re-activated later when a new user password is set. If you
execute this command on disabling the security mode feature (device lock function), the password sent by
the host is N O T compared with the password stored in the device for both the Master Password and the
User Password, and then the device only erases all user data.
The execution time of this command is set in word 89 of Identify device information.
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Command Descriptions