Browse Prior Art Database

Hard Disk Drive Access Password Support for Power Management

IP.com Disclosure Number: IPCOM000114250D
Original Publication Date: 1994-Nov-01
Included in the Prior Art Database: 2005-Mar-28
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Shimizu, T: AUTHOR [+2]

Abstract

Disclosed is a hard disk drive unit that is capable of locking and unlocking by itself and of controlling the unlocked mode tactically to facilitate power management operations in the computer system.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 91% of the total text.

Hard Disk Drive Access Password Support for Power Management

      Disclosed is a hard disk drive unit that is capable of locking
and unlocking by itself and of controlling the unlocked mode
tactically to facilitate power management operations in the computer
system.

      The drive unit requires a valid access password at every
power-on reset before it starts normal operations.  Unless and until
a valid password is entered successfully, the drive unit does not
start normal operation.

      The drive unit monitors the electric voltage level on a pin of
the interface connector to the host computer.  The host computer
maintains the voltage level at a logical high as long as the computer
is in running mode or suspend mode, but changes it to a logical low
when the computer enters hibernation mode or gets powered off.  The
drive unit senses the voltage level to determine whether it stays
unlocked or changes to lock itself.  As long as the voltage level is
high, the drive unit is unlocked, and does not require the password
to be entered.  If the voltage level becomes low, the drive unit
shuts itself up and requires a valid access password to be entered
before restarting normal operation.

      The drive unit senses any high-to-low voltage transition when
it is in running and suspend mode.  When the power supply is removed
out of the drive unit or the computer, then the drive unit recognizes
that a high-to-low transition has occurred.  The above is true i...