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Input and Output Devices
This chapter describes the Xserve G5’s built-in I/O devices and the ports for connecting external I/O devices. Each of the following sections describes an I/O port or device.
USB Ports
The Xserve G5 has two external Universal Serial Bus (USB) 2.0 ports. The USB ports are off of the USB controller connected to the PCI bus, bridged by K2. All USB ports are fully compliant with the USB 2.0 specification, including support for high-speed (480 Mbps) devices using an Enhanced Host Controller Interface (EHCI). Ports are automatically routed to a companion Open Host Controller Interface (OHCI) controller when a classic-speed (full-speed or low-speed) USB device is attached to a root hub port.
For low-speed and full-speed devices, the USB register set complies with the OHCI specification. For high-speed devices, the USB register set complies with the EHCI specification.
For more information about USB, refer to sources listed in USB Interface.
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.
Pin | Signal name | Description |
|---|---|---|
1 | VCC | +5 VDC |
2 | D– | Data – |
3 | D+ | Data + |
4 | GND | Ground |
The Xserve G5 provides power for the USB ports at 5 V and up to 500 mA on each port. The ports share the same power supply; a short circuit on one will disable both 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.
FireWire Ports
The Xserve G5 has three external FireWire ports: two FireWire 800 on the rear panel of the enclosure and one FireWire 400 on the front. The bilingual FireWire 800 ports have 9-pin connectors and support transfer rates up to 800 Mbps; the FireWire 400 port has a 6-pin connectors and supports transfer rates of 100, 200, and 400 Mbps. As long as security is not engaged, the Xserve G5 can boot through FireWire; see Booting from a FireWire Device.
provide a total of 15 watts of power when the computer system is on
support up to 61 devices (each Xserve G5 has 2 internal devices)
provide bus repeating capability as long as the computer is connected to AC power
The FireWire hardware and software provided with the Xserve G5 are capable of all asynchronous and isochronous transfers defined by IEEE standards 1394a and 1394b.
Developers of FireWire peripherals are required to provide device drivers. A driver for DV (digital video) is included in QuickTime 4.0 and later.
For more information about FireWire on Macintosh computers, please refer to the Apple FireWire website and the other sources listed in FireWire Interface.
FireWire 800 Connector
The FireWire 800 port on the Xserve G5 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 3-2. Its connector signals and pin assignments are shown in Table 3-2.
Pin | Signal name | Description |
|---|---|---|
1 | TPB– | Twisted-pair B Minus |
2 | TPB+ | Twisted-pair B Plus |
3 | TPA– | Twisted-pair A Minus |
4 | TPA+ | Twisted-pair A Plus |
5 | TPA (R) | Twisted-pair A Ground Reference |
6 | VG | Power Ground |
7 | SC | Status Contact (no connection; reserved) |
8 | VP | Power Voltage (18 to 25 V DC) |
9 | TPB (R) | Twisted-pair B Ground Reference |
VP (pin 8) provides up to 15 W power, shared with the other FireWire connectors. The voltage on the power pin is 18 to 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 Xserve G5 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 port has a connector with six pins, as shown in Figure 3-3. The connector signals and pin assignments are shown in Table 3-3.
Pin | Signal name | Description |
|---|---|---|
1 | Power | Power (approximately 25 V DC) |
2 | Ground | Ground return for power and inner cable shield |
3 | TPB– | Twisted-pair B Minus |
4 | TPB+ | Twisted-pair B Plus |
5 | TPA– | Twisted-pair A Minus |
6 | TPA+ | Twisted-pair A Plus |
Shell | — | Outer cable shield |
The power pin provides up to 15 W total power for all three FireWire connectors. The voltage on the power pin can be from 18 to 25 V.
Pin 2 of the FireWire 400 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.
Booting from a FireWire Device
Xserve G5 can boot from a FireWire storage device that implements SBP-2 (Serial Bus Protocol) with the RBC (reduced block commands) command set. Detailed information is available from Developer Technical Support: dts@apple.com.
For additional information about the FireWire interface and the Apple APIs for FireWire device control, see the references shown in FireWire Interface.
Ethernet Ports
The Xserve G5 provides dual, independent, gigabit Ethernet supporting 10Base-T, 100Base-T, and 1000Base-T transfer rates. In operation, the actual speed of each link is auto-negotiated between the computer’s PHY device and the hub, switch, or router to which it the port is connected. Both the gigabit Ethernet card and the built-in gigabit Ethernet ports offer Jumbo Frame support.
The connectors for the Ethernet ports are RJ-45 connectors on the back of the computer. Table 3-4 shows the signals and pin assignments for 10Base-T and 100Base-T operation. Table 3-5 shows the signals and pin assignments for 1000Base-T operation.
Pin | Signal name | Signal definition |
|---|---|---|
1 | TXP | Transmit (positive lead) |
2 | TXN | Transmit (negative lead) |
3 | RXP | Receive (positive lead) |
4 | – | Not used |
5 | – | Not used |
6 | RXN | Receive (negative lead) |
7 | – | Not used |
8 | – | Not used |
Pin | Signal name | Signal definition |
|---|---|---|
1 | TRD+(0) | Transmit and receive data 0 (positive lead) |
2 | TRD–(0) | Transmit and receive data 0 (negative lead) |
3 | TRD+(1) | Transmit and receive data 1 (positive lead) |
4 | TRD+(2) | Transmit and receive data 2 (positive lead) |
5 | TRD–(2) | Transmit and receive data 2 (negative lead) |
6 | TRD–(1) | Transmit and receive data 1 (negative lead) |
7 | TRD+(3) | Transmit and receive data 3 (positive lead) |
8 | TRD–(3) | Transmit and receive data 3 (negative lead) |
To interconnect two computers for 1000Base-T operation, you must use 4-pair cable (Category 5 or 6).
The Ethernet interface in the Xserve G5 conforms to the ISO/IEC 802.3 specification, where applicable, and complies with IEEE specifications 802.3i (10Base-T), 802.3u-1995 (100Base-T), and 802.3ab (1000Base-T).
Serial Port
The Xserve G5 has an RS-232-compatible serial port for connecting a terminal, using a standard DB-9 plug. Figure 3-4 shows the mechanical arrangement of the pins on the serial port connector; Table 3-6 shows the signal assignments.
The serial ports include a GPi (general-purpose input) signal on pin 7. The GPi signal connects to the data carrier detect input on the SCC (Serial Communications Controller). Alternatively, the GPi line can be connected to the receive/transmit clock (RTxCA) signal on the SCC. That connection supports devices that provide separate transmit and receive data clocks, such as synchronous modems.
Pin | Signal name | Signal description |
|---|---|---|
1 | RLSD | Received line signal detector |
2 | RD | Received data |
3 | TD | Transmitted data |
4 | DRT | DTE ready |
5 | SGND | Signal ground |
6 | DCR | DCE ready |
7 | RTS | Request to send |
8 | CTS | Clear to send |
9 | RI | Ring indicator (wake up system) |
Disk Drives
The standard Xserve G5 has three bay modules supporting up to three internal hard disk drives. The cluster node Xserve G5 has a single internal bay with one drive. Depending on the configuration purchased, some bays may be empty; empty bays are filled with blank drive carrier modules. The standard Xserve G5 also supports a Combo drive or a build-to-order SuperDrive.
Combo Drive
The standard Xserve G5 supports a slot-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.
Media type | Reading speed | Writing speed |
|---|---|---|
DVD-R | 8x (CAV max) | – |
DVD-ROM | 8x (CAV max) | – |
CD-R | 24x (CAV max) | 24x (ZCLV) |
CD-RW | 24x (ZCAV max) | 16x (ZCLV, for Ultra speed media) |
CD or CD-ROM | 24x (CAV max) | – |
SuperDrive (Optional)
The standard Xserve G5 supports an optional, slot-loading SuperDrive (combination DVD-R and CD-RW drive).
The SuperDrive can read DVD media and read and write CD media, as shown in Table 3-8.
Media type | Reading speed (maximum) | Writing speed |
|---|---|---|
DVD-R | 6x (CAV max) | 8x ZONE CLV, 4x/2x/1x (CLV) depending on media type |
DVD-RW | 6x (CAV max) | 4x/2x/1x (CLV) depending on media type |
DVD-ROM | 8x (CAV max) | _ |
CD-R | 24x (CAV max) | 24x ZONE CLV |
CD-RW | 24x (CAV max) | 14 (CLV) high speed CD-RW disc |
CD or CD-ROM | 24x (CAV max) | – |
The Apple SuperDrive writes to DVD-R 4.7 gigabyte General Use media. These discs are playable in most standard DVD players and computer DVD-ROM drives.
For compatibility information regarding recordable DVD formats, refer to
Hard Disk Drives
The standard Xserve G5 enclosure has three drive bays for three fixed-media mass storage devices. For software applications, the bays are numbered one to three from left to right. In Open Firmware, the bays are numbered SD0 to SD2 from left to right. The cluster node Xserve G5 enclosure has a single drive bay on the left, which is referred to as 1 on the panel and SD0 in Open Firmware.
The drives on the independent Serial ATA buses implement revision one ports. For references to SATA website information, refer to Serial ATA .
Each drive carrier has two LEDs. The top one is a multicolor LED indicating drive state as follows:
Green: Drive in normal use by system
Yellow: Drive changing state (spinning up or down) or pre-failure warning
Red: Drive has failed
No color: No power to drive
The bottom (blue) LED indicates the individual drive’s disk activity.
The monitoring software supports only drive modules manufactured by Apple.
VGA Connector
As a build-to-order option, the Xserve G5 slot load can have a video graphics card installed in Bus A of the PCI-X bridge. The card has a VGA connector for the video monitor.
The VGA connector is a three-row DB-15 (also called mini sub D15) connector for use with a VGA, SVGA, or XGA monitor. Figure 3-5 shows the pin configuration and Table 3-9 lists the signals and pin assignments.
Pin | Signal name | Description |
|---|---|---|
1 | RED | Red video signal |
2 | GREEN | Green video signal |
3 | BLUE | Blue video signal |
4 | n.c. | No connect |
5 | GND | Ground |
6 | RED_RTN | Red video signal return |
7 | GREEN_RTN | Green video signal return |
8 | BLUE_RTN | Blue video signal return |
9 | n.c. | No connect |
10 | GND | Ground |
11 | n.c. | No connect |
12 | SDA | I2C data |
13 | HSYNC | Horizontal synchronization signal |
14 | VSYNC | Vertical synchronization signal |
15 | SCL | I2C clock |
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