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 shows the connector and Table 3-1 shows the signals and pin assignments.

The Power Mac G5 computer provides 5 V power for the USB ports and up to 500 mA on each port. The power is provided in both run and sleep mode. The ports share the same power supply; a short circuit on one disables all ports until the short has been removed.

The USB ports support all USB 2.0 speeds: high-speed (480 Mbps) and classic USB speeds of full-speed (12 Mbps) and low-speed (1.5 Mbps). High-speed operation requires the use of shielded cables.

The Macintosh system software supports all four data transfer types defined in the USB specification, as well as split transactions for classic-speed devices attached to high-speed hubs.

Waking Up From Sleep

As defined in the USB-suspend mode of the USB specification, USB devices can provide a remote wakeup function for the computer (resume signalling). The USB root hub in the computer is set to support remote wakeup whenever a device is attached to the bus. The device wakes the computer by sending a RESUME event to the USB root hub. The mouse and keyboard that come with the computer use this method to wake the computer on a key press or mouse click.

FireWire 800 Connector

The FireWire 800 port on the Power Mac G5 computer 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 1394a (FireWire 400) 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 3-2. Its connector signals and pin assignments are shown in Table 3-2.

VP (pin 8) provides up to 15 W power, shared with the other FireWire connectors. The voltage on the power pin is approximately 25 V.

The 9-pin FireWire port is capable of operating at 100, 200, 400, and 800 Mbps, depending on the device it is connected to. 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 Power Mac G5 computer 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 400 Connector

The FireWire 400 ports 1 and 2 use the six-pin connectors shown in Figure 3-3. The connector signals and pin assignments are shown in Table 3-3.

The power pin provides up to 15 W total power, shared with the other FireWire connectors. The voltage on the power pin is approximately 25 V.

Pin 2 of the 6-pin FireWire connector is ground return for both power and the inner cable shield. In a FireWire cable with a 4-pin connector on the other end, the wire from pin 2 is connected to the shell of the 4-pin connector.

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 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 IO Kit can match protocols and drivers to each connected FireWire device.

The specific device and protocol support in Mac OS X as provided with the Power Mac G5 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/

Booting from a FireWire Device

The Power Mac G5 computer can boot from a FireWire storage device that implements SBP-2 (Serial Bus Protocol) with the RBC (reduced block commands) command set.

For additional information about the FireWire interface and the Apple API for FireWire device control, see the references shown in FireWire Interface.

Target Disk Mode

The user has the option at boot time to put the computer into a mode of operation called Target Disk Mode (TDM). When the Power Mac G5 computer is in Target Disk Mode and connected to another Macintosh computer by a FireWire cable, the Power Mac G5 computer 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 Power Mac G5 computer can operate in Target Disk Mode as long as the other computer has a 1394a or 1394b FireWire port and either any version of Mac OS X or Mac OS 9 with FireWire software version 2.3.3 or later.

To put the Power Mac G5 computer into Target Disk Mode, restart the computer and hold down the T key until the FireWire icon appears on the display. Then connect a FireWire cable from the Power Mac G5 to the other computer. When the other computer completes the FireWire connection, a hard disk icon appears on its desktop.

If you disconnect the FireWire cable or turn off the Power Mac G5 computer while in Target Disk Mode, an alert appears on the other computer.

To take the Power Mac G5 out of Target Disk Mode, drag the hard disk icon on the other computer to the trash, then press the power button on the Power Mac G5 computer.

Hard Disk Drives

The enclosure has one drive carrier with two 3.5 inch bays for fixed-media mass storage devices. The drive carrier has data and power connectors for the both drives. The two drives on the independent Serial ATA buses implement revision one ports. Hard disk drive capacities are 160 GB and 250 GB with a 400 GB build-to-order option for some configurations. For references to SATA website information, refer to Serial ATA.

SuperDrive

The Power Mac G5 computer has a tray-loading 16x SuperDrive (combination DVD+R double-layer, DVD+/-RW, and CD-RW drive). The SuperDrive can read and write DVD media and CD media, as shown in Table 3-6.

The Apple SuperDrive writes to General Use media as follows: DVD-R 4.7 GB and DVD+R DL 8.5 GB. These discs are playable in most standard DVD players and computer DVD-ROM drives.

For compatibility information regarding recordable DVD formats, refer to

http://dvddemystified.com/dvdfaq.html#4.3

Digital audio signals from the SuperDrive can be played through the sound outputs under the control of the Sound Manager.

Combo Drive

As a build-to-order option, the Power Mac G5 computer can have a tray-loading combination DVD-ROM and CD-RW drive.

The Combo drive can read DVD media and read and write CD media, as shown in Table 3-7.

Digital audio signals from the Combo drive can be played through the sound outputs under the control of the Sound Manager.

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 software or 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

The AirPort Extreme Card is a wireless LAN module compliant with the IEEE 802.11g standard using 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.

The AirPort Extreme wireless interface is on the PCI bus.

AirPort Extreme Software

Software that is provided with the AirPort Extreme Card includes:

• 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.

Keyboard Features

Here is a list of the features of the Apple Keyboard.

• sloped design

• 109 keys (on the ANSI versions)

• 16 function keys

• 6 editing keys (Page Up, Page Down, Home, End, Forward Delete, and Help)

• USB HID Consumer Page Usage multimedia control keys

• full travel, standard pitch keys on alphanumeric, editing, and keypad sections, including function keys and cursor-position keys

• localized worldwide: 33 versions, standard layouts (including: ANSI, JIS, ISO)

• LED indicator on the Caps Lock key

• USB hub functionality with two USB 1.1 sockets

Keyboard Layout

There are localized versions of the Apple Keyboard for use in different parts of the world. The three standards used are ANSI (US and North America), JIS (Japan), and ISO (Europe).

Applications can determine which keyboard is connected by calling the Gestalt Manager and checking for the corresponding value of the gestaltKeyboardType selector.

Figure 3-4 shows the keyboard layout for the ANSI keyboard.

MultiMedia Control Keys

The keyboard has six multimedia keys: Volume Up, Volume Down, Mute, Brightness Up (F15), Brightness Down (F14), and Eject. Theses keys provide direct control of the features on the computer by way of the USB.

Keyboard and USB

The Apple Keyboard is designed to work with the computer by way of the USB ports. The keyboard has a captive cable with a USB Type A connector. The keyboard is a bus-powered USB hub with two USB Type A ports.

Apple provides a HID class driver for the Apple Keyboard, which supports the USB boot protocol. Other keyboards intended for use on the Macintosh platform must support the HID boot protocol, as defined in the USB Device Class Definition for Human Interface Devices (HIDs).

Programmer’s Switches

Key combinations for programmer’s switches that used the Power button on earlier models now use the Eject key. Here are the key combinations for the Power Mac G5 computer.

• Control-Command-Eject: restart immediately (reset)

• Control-Command-Option-Eject: shut down immediately

• Control-Eject: display the dialog for shutdown, restart, and sleep

The key combinations are decoded in software and may not be available under some crashed conditions.

% nvram boot-args

% sudo nvram boot-args="<current settings> debug=0x4"

% sudo nvram boot-args=""

Optical Digital Audio

Digital data is transmitted to and from the digital audio I/O using optical cables. The physical connectors, commonly referred to as TOSLink, are for both input and output and conform to IEC60874-17. The TOSLink friction-lock type F-05 connectors are available from pro-audio, musician’s supply, hi-fi and other retailers. The 7.5 mm digital optical TOSLink input and output connectors, shown in Figure 3-5, are located on the back of the enclosure.

The digital I/O circuitry can either perform input clock recovery on an incoming data stream or can sample using the internal clock. If samples are clocked using the internal clock, the data is run through the sample-rate converter on the digital circuitry. To enable bit-accurate copies, the external clock should be enabled in Audio MIDI Setup. Developers of applications that need this capability will need to provide access to the input clock recovery control.

Audio signals from the audio input jack 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, the headphones, line output jacks, or external speakers.

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

The Power Mac G5 computer also has the ability to lock 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.

The Power Mac G5 computer’s audio subsystem has built-in sample-rate conversion (SRC) that allows the incoming audio to have a different rate than the playback audio, enabling the audio to come in the digital-in connector. For the best digital input quality in its purest form, set the audio clocking preference to “External Clock.”

Audio Line-in

The Power Mac G5 has a stereo audio line-in jack on the back panel. The audio inputs are designed to accept high-level audio signals: 2 Vrms or +8 .2 dbu, which is the standard output level from CD and DVD players. The output level of some consumer audio devices is lower, often 0.316 Vrms or –10 dbV. Sound recordings made on the Power Mac G5 with such low-level devices have more noise than those made with high-level devices. The user may obtain better results by connecting an amplifier between the low-level device and the computer’s audio input jack.

The audio input jack is a 3.5 mm miniature phone jack with the signals connected as follows:

Based on a 1 kHz, 2VRMS sine wave input, 24-bit 44.1 kHz input format, 0 db input gain and no weighting, the line input has the following electrical characteristics :

• maximum input voltage: 2 Vrms (+8.2 dBu)

• input impedance: > 47 kilohms

• bits per sample: 16-bit or 24-bit

• channel separation: greater than 75 dB

• frequency response: 20 Hz to 20 kHz, +0.5 dB/–3.0 dB

• THD+N distortion: below –78 dB (no weighting)

Audio Line-out

The Power Mac G5 has a stereo output jack on the back of the enclosure. The audio output jack is suitable for connecting amplified external speakers or other high input impedance (> 1K ohms) audio equipment.

The audio output jack is a 3.5 mm miniature phone jack with the signals connected as follows:

Based on a 1 kHz, -1 dBFS sine wave playback, 24-bit 44.1 kHz output format, -3 db output level and 100 kilohm load no weighting (unless otherwise specified below) , the line output has the following electrical characteristics (nominal specifications):

• output voltage (full-scale output): 1.4 Vrms (+5.1 dBu)

• output impedance: <50 ohms

• bits per sample: 16-bit or 24-bit

• channel separation: > 65 dB

• THD+N (total harmonic distortion plus noise): < –78dB (0.0125%) no weighting

• frequency response: 20 Hz to 20 kHz, +0.5 dB/–3.0 dB

Headphone Jack

The Power Mac G5 has a stereo headphone jack on the front of the enclosure. The headphone jack is suitable for connecting a standard pair of headphones. When a plug is inserted into the headphone jack, the internal speaker is muted.

The headphone jack is a 3.5 mm miniature phone jack with the signals connected as follows:

Based on a 1 kHz sine wave playback, 24-bit 44.1 kHz output format, -3 dB output level and 100 kilohm load no weighting (unless otherwise specified), the headphone output has the following electrical characteristics (nominal specifications):

• output voltage (full-scale output): 1.4 Vrms, (+5.1 dBu)

• output impedance: <50 ohms

• bits per sample: 16-bit or 24-bit

• channel separation: > 60 dB

• frequency response: 20 Hz to 20 kHz, +0.5 dB/–3.0 dB

• THD+N (total harmonic distortion plus noise): < –75dB (0.017%) no weighting

DVI Connector

The supported graphics cards have either one or two DVI-I (DVI with analog) connectors. With a DVI to ADC adapter, available separately and shown in Figure 3-6, the DVI port on the Power Mac G5 computer can also support any Apple flat panel display that uses the flat panel connector.

Figure 3-7 shows the contact configuration for the DVI connector; Table 3-9 lists 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 information about TMDS, see the reference listed in Digital Visual Interface.

Apple Display Connector

The ADC connector on the adapter carries both digital and analog video signals as well as USB and control signals and power for an external monitor. Figure 3-8 shows the contact configuration; Table 3-10 and Table 3-11 list the signals and pin assignments.

The maximum current available from the 25 V supply for the external monitor is 3.6 A.

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.

DVI to Video Adapter

The Power Mac G5 computer supports an optional DVI to S-video/composite adapter that provides S-video and composite output to a PAL or NTSC video monitor or VCR. When a display is connected by way of the video adapter, the computer detects the type of adapter and enables the composite and S-video outputs. The settings for the resolutions and standards (NTSC or PAL) are then selectable in the System Preferences Displays pane.

The video output connector is a 7-pin S-video connector. Figure 3-9 shows the arrangement of the pins and Table 3-12 shows the pin assignments on the composite out and S-video connector.

The Power Mac G5 computer provides video output at picture sizes and frame rates compatible with the NTSC and PAL standards; the picture sizes are listed in Table 3-13. Those picture sizes produce under-scanned displays on standard monitors.