IEEE-1394 (FireWire)

IEEE-1394 is a family of high-speed bidirectional serial transmission ports that can connect PCs to each other, digital devices to PCs, or digital devices to each other.

The most common version of IEEE-1394 is known as IEEE-1394a, and is also known as FireWire 400. Sony's version is known as i.LINK . At 400Mbps, IEEE-1394a is one of the fastest and most flexible ports used on personal computers. IEEE-1394a can be implemented either as a built-in port on the motherboard or as part of an add-on card (see Figure 8.30).

Figure 8.30. Two typical locations for IEEE-1394a ports on the rear of a typical ATX-class computer.

Some IEEE-1394a add-on cards also provide an internal port for the growing number of internal IEEE-1394 devices.

A faster version of the IEEE-1394 standard, IEEE-1394b, was introduced in early 2003. Also known as FireWire 800, 1394b ports and devices transfer data at 800Mbps. Future versions will reach higher speeds.

A growing number of high-end sound cards (such as the one shown in Figure 8.25) also feature IEEE-1394a ports. If you're in the market for a high-end sound card, choosing a sound card with a built-in IEEE-1394a port could let one card do the work of two.

IEEE-1394 Ports and Cables

Standard IEEE-1394a ports and cables use a 6-pin interface (four pins for data, two for power), but some digital camcorders and all i.LINK ports use the alternative 4-pin interface, which supplies data and signals but no power to the device. Six-wire to four-wire cables enable these devices to communicate with each other.

IEEE-1394b ports use a 9-pin interface. There are two versions of the IEEE-1394b port: The Beta port and cable are used only for 1394b-to-1394b connections, whereas the Bilingual cable and port are used for 1394b-to-1394a or 1394b-to-1394b connections. Beta cables and ports have a wide notch at the top of the cable and port, whereas Bilingual cables and ports have a narrow notch at the 1394b end, and use either the 4-pin or 6-pin 1394a connection at the other end of the cable. All four cable types are shown in Figure 8.31.

Figure 8.31. 1394b and 1394a cable connectors compared.

IEEE-1394Compatible Devices and Technical Requirements

IEEE-1394compatible devices include internal and external hard drives , digital camcorders (also referred to as DV camcorders), Web cameras , MP3 players (such as Apple's iPod) and high-performance scanners and printers, as well as hubs, repeaters, and SCSI to IEEE-1394 converters. IEEE-1394 ports support hot-swapping, enabling you to add or remove a device from an IEEE-1394 port without shutting down the system. 1394 ports can also be used for networking.

Up to 16 IEEE-1394 devices can be connected to a single IEEE-1394 port through daisy-chaining. Most external IEEE-1394 devices have two ports to enable daisy-chaining.

Windows 98/Me/2000/XP all include IEEE-1394 support; Windows 95 and Windows NT 4.0 and earlier NT versions do not. IEEE-1394 cards are PCI-based and require the following hardware resources:

• One IRQ (it can be shared on systems that support IRQ sharing by PCI devices)

• One memory address range (must be unique)

The exact IRQ and memory address range used by a particular IEEE-1394 card can be determined by using the Windows Device Manager. When an IEEE-1394 card is installed, a device category called 1394 Bus Controller is added to the Device Manager, and the particular card installed is listed beneath that category.

Installing an IEEE-1394 Card

To install and configure the card

1. Turn off the computer and remove the case cover.

2. Locate an available PCI expansion slot.

3. Remove the slot cover and insert the card into the slot. Secure the card in the slot.

4. Some IEEE-1394 cards are powered by the PCI expansion slot, whereas others require a 4-pin connector used by hard drives or floppy drives for power. Connect a power lead if the card requires it; you can use a Y-splitter to free up a power lead if necessary (see Figure 8.32).

   Figure 8.32. A typical IEEE-1394a card after installation. This card requires a four-wire power cable and also includes an internal port.

   

5. Close up the system, restart it, and provide the driver disk or CD-ROM when requested by the system.

6. The IRQ and memory address required by the card will be assigned automatically.