USB Connectors

The USB ports use USB Type A connectors, which have four pins each. Two of the pins are used for power and two for data. Figure 3-1 is an illustration of a Type A port and matching connector. Table 3-1 shows the pin assignments.

The computer provides 5-volt power at 500 mA for each of the two ports.

The external USB 2.0 ports support low-speed (1.5 Mbps), full-speed (12 Mbps), and high-speed (480 Mbps) data transfers. High-speed operation requires the use of shielded cables.

The 17-inch PowerBook G4 supports all four data transfer types defined in the USB specification.

USB devices can provide a remote wakeup function for the computer. The USB root hub in the computer is set to support remote wakeup whenever a device is attached to the bus.

USB Class Drivers

Class drivers are software components that are able to communicate with many USB devices of a particular kind. If the appropriate class driver is present, any number of compliant devices can be plugged in and start working immediately without the need to install additional software.

FireWire 400 Connector

The 6-pin FireWire 400 technology

• supports serial I/O at 100, 200, and 400 Mbps

• provides up to 7 watts of power when the computer system is on or when the power adapter is connected and in sleep mode

The FireWire 400 connector has six contacts, as shown in Figure 3-2. The connector pin assignments are shown in Table 3-2.

When the computer is on or the power adapter is connected, the power pin provides a maximum voltage of 12.8 V (no load) and 7 W power per port. Maximum output current for both ports combined is 1.5 A and is controlled by a self-resetting fuse.

Pin 2 of the 6-pin FireWire connector is ground for both power and the inner cable shield. If a 4-pin connector is used on the other end of the FireWire cable, its shell should be connected to the wire from pin 2.

The signal pairs are crossed in the cable itself so that pins 5 and 6 at one end of the cable connect with pins 3 and 4 at the other end. When transmitting, pins 3 and 4 carry data and pins 5 and 6 carry clock; when receiving, the reverse is true.

FireWire 800 Connector

The FireWire 800 port on the 17-inch PowerBook G4 is based on IEEE 1394b and enables a 800 Mbps transfer rate. FireWire 800 uses a 9-pin connector and is backwards compatible with original 1394 FireWire devices with 6-pin or 4-pin connectors. With the appropriate cable, the 9-pin port works seamlessly with legacy FireWire devices. Cables are available to go from both 6-pin and 4-pin connectors to a 9-pin, and 9-pin to 9-pin.

The 9-pin FireWire 800 connector is shown in Figure 3-3. Its connector signals and pin assignments are shown in Table 3-3.

VP (pin 8) provides up to 7 W power, shared with the other FireWire connectors. The voltage on the power pin is approximately 12.8 V.

The 9-pin FireWire 800 port is capable of operating at 100, 200, 400, and 800 Mbps, depending on the device to which it is connected. The FireWire 800 port is bilingual in that it supports both IEEE 1394a and 1394b. Using a cable with a 9-pin connector at one end and a 4-pin or 6-pin connector at the other, the 9-pin port is capable of directly connecting to all existing FireWire devices. Using a cable with 9-pin connectors at both ends, the 9-pin port is capable of operating at 800 Mbps.

The IEEE 1394b standard defines long-haul media using Cat 5 UTP and several kinds of optical fiber. The 17-inch PowerBook G4 is interoperable with such cables but cannot be directly connected to them. To use long-haul cables, connect the computer to a 1394b hub that has the desired kind of long-haul connectors. If the hub has a bilingual port, that port can be connected to any of the computer’s FireWire ports. If the hub has a beta-only port, it can be connected only to the computer’s 9-pin port.

FireWire Device Programming

Mac OS X includes general support for the FireWire bus and specific support for various kinds of FireWire devices and protocols. Developers can use the built-in support or provide additional applications and drivers for use with their products.

The general FireWire services will configure the FireWire bus, scan the bus for new devices, and allow multiple drivers and devices to share a single FireWire interface cooperatively. The general services also publish information about the bus and the devices in the IO Registry, so that IOKit can match protocols and drivers to each connected FireWire device.

The specific device and protocol support in Mac OS X as provided with the 17-inch PowerBook G4 includes the following:

• General services for Serial Bus Protocol 2 (SBP-2) and support for most mass storage devices using SBP-2, such as hard disk drives, optical drives, flash card readers, Target Disk Mode (see Target Disk Mode), and the iPod. Mac OS X can boot from most of these devices.

• General services for the Audio Video Control (AV/C) protocol and support for most digital video (DV) cameras and decks using this protocol, including video capture through standard QuickTime APIs.

• A QuickTime device driver for IIDC/DCAM type cameras such as the iSight.

• A network device driver supporting IP (Internet Protocol) over FireWire according to IEEE RFC 2734.

• Additional services for user-space and kernel access to all FireWire resources.

For information on writing FireWire drivers or applications, download the latest FireWire SDK from http://developer.apple.com/sdk/.

For additional references, refer to FireWire Interface.

Target Disk Mode

One option at boot time is to put the computer into a mode of operation called target disk mode.

When the 17-inch PowerBook G4 is in target disk mode and connected to another Macintosh computer by a FireWire cable, the 17-inch PowerBook G4 operates like a FireWire mass storage device with the SBP-2 (Serial Bus Protocol) standard. Target disk mode has two primary uses:

• high-speed data transfer between computers

• diagnosis and repair of a corrupted internal hard drive

The 17-inch PowerBook G4 can operate in target disk mode as long as the other computer has a FireWire 1394a or 1394b port and is running either Mac OS X (any version) or Mac OS 9 with FireWire software version 2.3.3 or later.

To put the computer into target disk mode, hold down the T key while the computer is starting up. When Open Firmware detects the T key during the boot process, it transfers control to special Open Firmware code.

To take the computer out of target disk mode, press the power button.

Data Security

AirPort Extreme has several features designed to maintain the security of the user’s data.

• In 802.11b mode, the system uses direct-sequence spread-spectrum (DSSS) technology that uses a multi-bit spreading code that effectively scrambles the data for any receiver that lacks the corresponding code.

• The system can use an Access Control List of authentic network client ID values (wireless and MAC addresses) to verify each client’s identity before granting access to the network.

• When communicating with a base station, AirPort Extreme uses 64-bit and 128-bit WEP encryption and WPA personal and enterprise modes to encode data while it is in transit. Additional security features may be available via firmware upgrades as 802.11 enhancements are ratified by IEEE.

• The AirPort Extreme Base Station can be configured to use NAT (Network Address Translation), protecting data from Internet hackers.

• The AirPort Extreme Base Station can authenticate users by their unique Ethernet IDs, preventing unauthorized computers from logging into your network. Network administrators can take advantage of RADIUS compatibility, used for authenticating users over a remote server. Smaller networks can offer the same security using a local look-up table located within the base station.

As an additional data security measure, VPN can be used in conjunction with the AirPort Extreme data security.

AirPort Extreme Hardware

AirPort Extreme uses both OFDM (orthogonal frequency-division multiplexing) and DSSS technologies. Using DSSS, AirPort Extreme is interoperable with PC-compatible wireless LANs that conform to the 802.11b standard at speeds of 11 Mbps, 5.5 Mbps, 2 Mbps, and 1 Mbps. Using OFDM, AirPort Extreme is compatible with all 802.11g standard speeds.

Two antennas are built into the computer, on either side of the flat-panel display.

AirPort Extreme Software

The 17-inch PowerBook G4 includes software for setting up and using AirPort Extreme:

• AirPort Extreme Setup Assistant, an easy-to-use program that guides users through the steps necessary to set up AirPort Extreme or set up an AirPort Extreme Base Station.

• Users can switch between wireless networks and can create and join peer-to-peer networks. These functions are accessed via the AirPort Extreme status menu.

• AirPort Extreme Admin Utility, a utility for advanced users and system administrators. With it the user can edit the administrative and advanced settings needed for some advanced configurations.

Hard Disk Dimensions

Figure 3-4 shows the maximum dimensions of the hard disk and the location of the mounting holes. The minimum clearance between any conductive components on the drive and the bottom of the mounting envelope is 0.5 mm.

Hard Disk Connector

The internal hard disk has a 48-pin connector that carries both the ATA signals and the power for the drive. The connector has the dimensions of a 50-pin connector, but with one row of pins removed, as shown in Figure 3-5. The remaining pins are in two groups: pins 1–44, which carry the signals and power, and pins 45–48, which are reserved. Pin 20 has been removed, and pin 1 is located nearest the gap, rather than at the end of the connector.

Changing the Operation of the Keyboard

Several of the keys on the keyboard have more than one mode of operation.

• Function keys F1–F10 can also control features such the display brightness, the speaker volume, the dual display feature, the Num Lock function, and the illuminated keyboard brightness. Refer to Table 3-10 for the entire list. A media eject key is located to the right of the F12 function key.

• Certain control keys can be used as page-control keys.

• The keys on the right side of the keyboard can be used as a numeric keypad.

The next sections describe these groups of keys and the way their alternate modes of operation are selected by using the Fn key, and the Num Lock key.

Keyboard Illustrations

Figure 3-6 shows the actual appearance of the keyboard. Figure 3-7 shows the alternate modes of operation of the function and control keys. Figure 3-8 shows the embedded numeric keypad.

Figure 3-7 and Figure 3-8 include duplicate versions of some keys in order to show their alternate modes of operation. In some cases, the alternate key captions shown in the figures do not appear on the keyboard. For the actual appearance of the keyboard, refer to Figure 3-6.

Dual Display and Mirror Mode

An external monitor or projection device connected to the computer can increase the amount of visible desktop space. This way of using an external monitor is called dual display to distinguish it from mirror mode, which shows the same information on both the external display and the built-in display. Use the F7 key to switch between the dual display mode and the mirror mode.

When mirror mode is selected, the scaling function is available on the internal display, and on the internal display and an external monitor when both are operating. However, the monitors could have black borders during mirroring, depending on the supported timings between the two displays and on the monitor’s selection algotithm. Both displays show full-sized images only when the display resolution for the external monitor is set to the internal display’s 1680 by 1050 native resolution. Both displays can operate with other resolution settings, but in mirror mode, one of them has a display that is smaller than the full screen and has a black border around it. With the resolution for the external monitor set to 640 by 480 or 800 by 600, the image on the internal display is smaller than its screen. For resolution settings larger than 1680 by 1050, the image on the external monitor is smaller than its screen.

Analog Monitor Resolutions

The 17-inch PowerBook G4 comes with an adapter for use with an analog video monitor. Table 3-14 lists the standard picture sizes and frame rates supported.

When the built-in display and an external video monitor are operating at the same time, each is allocated 64 MB of video memory. This allocation is enough to support the full 24 bit pixel depth on the built-in display running at its native resolution of 1680 by 1050 as well as a 30-inch Apple Cinema HD Display running at its native resolution of 2560 by 1600 pixels.

Digital Display Resolutions

Table 3-15 shows the resolutions supported on flat-panel (digital) displays, with pixel depths up to 24 bits per pixel.

DVI-I Connector

The external monitor connector is a DVI-I connector. It carries both digital and analog video signals. Figure 3-9 shows the contact configuration; Table 3-16 and Table 3-17 list the signals and pin assignments.

The graphics data sent to the digital monitor use transition minimized differential signaling (TMDS). TMDS uses an encoding algorithm to convert bytes of graphics data into characters that are transition-minimized to reduce EMI with copper cables, and DC-balanced for transmission over fiber optic cables. The TMDS algorithm also provides robust clock recovery for greater skew tolerance with longer cables or low-cost short cables. For additional information about TMDS, see the references shown in Digital Visual Interface.

Optical Digital Audio

The digital I/O circuitry automatically performs input clock recovery on an incoming data stream. This enables bit-accurate copies of the digital data.

Audio signals from the audio input port are converted to digital data internally. All audio is handled digitally inside the computer, including audio data from the CD or DVD drive and from devices connected to the USB and FireWire ports. Audio data is converted to analog form for output to the internal speaker, combination headphones and optical digital audio output, or external speakers.

For details on the optical digital audio input and output electrical specifications, refer to Audio Line In and Digital Optical Audio Input and Digital Audio Output Specifications.

The 17-inch PowerBook G4 computer automatically locks its internal audio hardware to the incoming audio stream to synchronize the audio subsystem to an external device supplying the audio stream. This function allows audio and video to play in sync with the external audio or video device. The data format for signals transmitted over the optical cable is S/PDIF protocol IEC 60958-3.

Since the 17-inch PowerBook G4 does not support a hardware sample rate converter, core audio services provide the sample rate conversion.

Audio Inputs

The audio system accepts inputs from the following sources:

• the built-in microphone

• the combined optical digital audio input/audio line in port

• a CD or DVD in the optical drive

• a digital audio device connected to a USB or FireWire port

The audio line in and optical digital audio input port and the microphone preamp share a dedicated analog input channel in the audio circuitry; the other inputs send digital data. The analog input can be set for play-through or recording. The digital inputs can be selected or mixed by the audio audio circuitry.

The computer also accepts digital audio data from the optical drive or from devices connected to the USB or FireWire ports. Audio data from those sources can be sent to the audio system to be converted to analog form for output to the speakers and the combination headphone and optical digital audio output.

Audio Outputs

The audio system sends audio output signals to the built-in speakers and the combination optical digital audio output and headphone out port.

Digitizing Audio

The audio circuitry digitizes and records audio according to the audio input sample rate and bit depth selected in Audio MIDI setup. If a sound sampled at a higher or lower rate on another computer is played as output, the Sound Manager transparently up-samples or down-samples the sound to the audio output sample rate and bit depth selected in Audio MIDI setup prior to outputting to the audio circuitry.

When recording sound from a microphone, applications that may be affected by feedback should disable sound play-through by calling the Sound Manager functions.