ADC Home > Reference Library > Reference > Hardware & Drivers > Apple Hardware > 17-inch PowerBook G4 Developer Note >

< Previous PageNext Page > Hide TOC

Overview of 17-inch PowerBook G4

This chapter outlines the features of the 17-inch PowerBook G4, with emphasis on the changes from the previous model.

In this section:

New Features
All Features
Appearance
Peripheral Devices
System Software


New Features

Here is a list of the features that are new to the 17-inch PowerBook G4. Each feature is described in a later chapter, as indicated.

All Features

Here is a list of all features of the 17-inch PowerBook G4. Each feature is described in a later chapter, as indicated.

Appearance

Figure 1-1 is a front view of the 17-inch PowerBook G4. Figure 1-2 provides side views showing the I/O ports.


Figure 1-1  Front view of the computer

Front view of the computer


Figure 1-2  Side views showing I/O ports

Side views showing I/O ports

Peripheral Devices

Included with the computer are a 65 W Apple Portable Power Adapter, an S-video-to-composite cable, a DVI-to-VGA cable, and a modem cable. In addition to these devices, the following peripheral devices are available separately:

System Software

The 17-inch PowerBook G4 comes with Mac OS X version 10.3.3. For the latest information, see the references listed in “Mac OS X.”

Here are a few items of interest about the system software on the 17-inch PowerBook G4.

Open Firmware

System software on all current Macintosh models uses a design based on Open Firmware. With this approach, the ROM on the main logic board contains only the Open Firmware code needed to initialize the hardware and load an operating system. The rest of the system code is loaded into RAM from disk or from the network. For more information, see the references listed in “Open Firmware.”

Computer Identification

Rather than reading the box flag or the model string and then making assumptions about the computer’s features, applications that need to find out the features of the computer should use IORegistry calls to test for the features they require. IORegistry calls are part of the I/O Kit API. For more information, see the references listed at “I/O Kit.”

Asset management software that reports the kind of computer it is running on can obtain the value of the model property from the IOService plane of the IORegistry. For the 17-inch PowerBook G4, the value of the model property is PowerBook5,5.

Power Management

Apple’s power management techniques for the 17-inch PowerBook G4 are described in the following paragraphs.

Power Saving States

The power management protocols on the 17-inch PowerBook G4 support two power-saving states: idle and sleep.

The computer automatically enters idle state after a few hundred milliseconds of inactivity. If the computer is attached to a network, it is able to respond to service requests and other events directed to the computer while it is in idle state.

While it is connected to an AC power supply, the computer can also respond to network activity when it is in sleep state. The user can enable this feature by selecting Wake-on-LAN in the Energy Saver preference pane.

When operating on the battery in sleep state, the computer consumes less than 1 watt of power, meeting the Energy Star power-saving standard. When operating on the power adapter in sleep state, the combined computer and adapter consume 3 to 4 watts of power.

Important: Peripherals such as PCMCIA cards and USB devices that do not conform to the computer’s power management protocols prevent the computer from switching to sleep state and so deny the user the benefits of this energy-saving state.

Processor Power Management

To lower power consumption and heat generation, the 17-inch PowerBook G4 incorporates an automatic power management technique called dynamic frequency switching (DFS). DFS is designed to run at high processor speed and voltage when the demand on the processor is high, and to run at low processor speed and voltage when the demand on the processor is low. When DFS is enabled, the processor dynamically adjusts its speed based on the current needs of the system. The processor speed will switch between 1.5 GHz and 750 MHz.

Switching between different processor speeds and voltages is achieved by a transition that should operate seamlessly to the user. For applications that are particulary demanding on the processor, it is recommended that the processor performance be set to highest.

The 17-inch PowerBook G4 allows the user to control DFS mode. The options for specifying either high, reduced, or automatic processor speeds are located at System Preferences>Energy Saver>Show Details>Options>Processor Performance; then select Highest, Automatic, or Reduced. DFS is enabled with the automatic setting.

If the 17-inch PowerBook G4 detects a system temperature that is high, due to high ambient temperatures or other factors, it will automatically force the system to reduced speed mode regardless of the selected setting.

Note:  The 17-inch PowerBook G4 meets all applicable safety standards, including UL 60950 and IEC 60950.

Note: The memory bus speed is not shifted, as it was in previous models.



< Previous PageNext Page > Hide TOC

© 2003, 2004 Apple Computer, Inc. All Rights Reserved. (Last updated: 2004-04-19)

Did this document help you?
Yes: Tell us what works for you.
It’s good, but: Report typos, inaccuracies, and so forth.
It wasn’t helpful: Tell us what would have helped.