IEEE 1394

IEEE 1394, called FireWire by Apple Computer is a type of interconnection generally used between a computer and its peripherals; it is not a local area network. Its main competitor is the Universal serial bus (USB).

There are IETF specifications for running IPv4 and IPv6 over FireWire.

It has had wide operating system support. Full support for IEEE 1394a and 1394b is available for FreeBSD, Linux and Apple Mac OS X operating systems. Microsoft Windows XP supports 1394a and 1394b, but as of service pack 2 the default speed for all types of FireWire is S100 (100 Mbit/second). A download and registry modification is available from Microsoft to restore performance to either S400 or S800. Microsoft Windows Vista will initially support 1394a, with 1394b support coming later in a service pack.

The original deployment used six pins, still much simpler than parallel SCSI, with two dedicated to providing power to an attached device. Sony's implementation, i.Link, uses a four-pin signal connector with a separate power connector. Be careful to keep connectors compatible.

In its applications of PC and advanced multimedia interconnect, it has replaced parallel SCSI. Apple was a strong initial supporter of FireWire, but no longer supports it on new iPods, preferring USB 2.0. There is some irony here, because Apple's requirement for patent royalties discouraged other manufacturers, such as Intel, from incurring that cost. USB 2.0 also takes cheaper hardware.

FireWire remains faster than USB 2.0, and retains all the logical capabilities of SCSI, which does not. Conversion to the ATA format, however, limits its transfer rate to about 50 MB/sec. Eventually, the IEEE created the "1394 Licensing Authority" that charges vendors $0.25 per end user system, the money supporting IEEE. FireWire has some advantages over comparable technologies. It has a much more flexible topology than parallel SCSI. It allows hot-swapping, direct communications (not via the CPU) between devices on the same FireWire system, and can supply power over its signal wires.