FireWire

The IEEE 1394 interface is a serial bus interface standard developed in 1995. It is knows by several other names such as i.LINK (Sony), Lynx (Texan Instruments) and most commonly FireWire (Apple). It supports speeds from 400-3200 Mbit/s (50-400MB/s), and was intended as a replacement for parallel SCSI.

Technical Details
IEEE 1394 supports transfer speeds from 400-3200 Mbit/s (50-400MB/s). Up to 63 peripherals can be linked together in a chain topology. Individual cables are up to 4.5m (15ft) long. It comes in 6-pin or 9-pin variations, with 45-watts of power per port at up to 30 volts.

Each device is identified by a unique ID number defined by [IEEE EUI-64] as well as codes identifying the type of device it is and the protocols supported.

The pin functions are as follows:


 * FireWire 400 (IEEE 1394) has a cable length limit of 4.5m(15ft), and can daisy chain 16 cables. Each device can pull 7-8 watts, although voltage varies. Voltage tends to average about 25 volts, but is listed as unregulated
 * IEEE 1394a is trademarked by Sony as i.LINK, and uses a 4-pin connector. It is compatible with 6-pin connectors, but lacks power connections.


 * Firewire 800 (IEEE 1394b-2002) allows 786.532Mbit/sec using a new encoding scheme and full-duplex. It is backwards compatible with the old 6-pin FireWire 400. The IEEE 1394b specification supports data rates up to 3200 Mbit/s over connection up to 100m.
 * FireWire S1600 and S3200 support 1,6Gbit/s and 3.23Gbit/s respectively.
 * Firewire S800T (IEEE 1394c-2006) has a new port specification that allows 800Mbit/s over the sane 8P8C (Ethernet cable) connectors.