Power Management; Power Management Modes - Acer 721TX - TravelMate - PII 333 MHz Service Manual

Power Management

This computer has a built-in power management unit that monitors system
activity. System activity refers to any activity involving one or more of the
following devices: keyboard, mouse, drive, hard disk, peripherals connected
to the serial and parallel ports, and video memory. If no activity is detected for
a period of time (called an inactivity time-out), the computer stops some or all
of these devices in order to conserve energy.
This computer employs a power management scheme that supports APM
(Advanced Power Management) or ACPI (Advanced Configuration and
Power Interface) which allows for maximum power conservation and
maximum performance at the same time.
If your computer is set for APM, you can set time-out values for your
computer's devices before power-saving methods are applied to these
devices. If your computer is set for ACPI, Windows 98 handles all power-
saving chores for your computer.
Note: Power management (APM or ACPI) greatly prolongs your battery
life.

Power Management Modes

Display Standby Mode
Screen activity is determined by the keyboard, the built-in touchpad, and an
external PS/2 pointing device. If these devices are idle for the period
specified by the LCD backlight Time-out value, the display shuts off until you
press a key or move the touchpad or external mouse.
"Automatic Dim" Feature
The computer has a unique "automatic dim" power-saving feature. When the
computer is using AC power and you disconnect the AC adapter from the
computer, it automatically dims the LCD backlight to save power. If you
reconnect AC power to the computer, it automatically adjusts the LCD
backlight to a brighter level.
Hard Disk Standby Mode
The hard disk enters Standby mode when there are no disk read/write
operations within the period of time specified by the Hard Disk Time-out
value. In this state, the power supplied to the hard disk is reduced to a
minimum. The hard disk returns to normal once the computer accesses it.
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