Hitachi HTS421212H9AT00 - Travelstar 120 GB Hard Drive Specifications page 173

Security Level
A zero indicates a High level, a one indicates a Maximum level. If the host sets the High level and the password is
forgotten then the Master Password can be used to unlock the device. If the host sets the Maximum level and the
user password is forgotten, only a Security Erase Prepare/Security Unit command can unlock the device and all
data will be lost.
Password
The 32 bytes are always significant in the text of the password.
Master Password Revision Code
The Revision Code field is set with Master password. If Identifier is User, the Revision Code is not set. The Revi-
sion Code field is returned in Identify Device word 92. The valid Revision Codes are 0001h to FFFEh. The Default
Master Password Revision Code is FFFEh. The code 0000h and FFFFh are reserved.
The setting of the Identifier and Security level bits interact as follows:
Identifier = User / Security level = High
The password supplied with the command will be saved as the new user password. The security mode feature
(lock function) will be enabled from the next power on. The drive may then be unlocked by either the user
password or the previously set master password.
Identifier = Master / Security level = High
This combination will set a master password but will NOT enable the security mode feature (lock function).
Identifier = User / Security level = Maximum
The password supplied with the command will be saved as the new user password. The security mode feature
(lock function) will be enabled from the next power on. The drive may then be unlocked by only the user pass-
word. The master password previously set is still stored in the drive but may NOT be used to unlock the
device.
Identifier = Master / Security level = Maximum
This combination will set a master password but will NOT enable the security mode feature (lock function).
Travelstar 4K120 Hard Disk Drive Specification
159