FireWire

FireWire is the trade name popularly used for IEEE 1394, a high-speed serial bus standard for connecting peripheral devices. Developed in the 1990s by Apple with involvement from other companies, it was marketed to consumers as a fast alternative to parallel ports for video cameras, external drives, and audio interfaces. The FireWire branding was complemented by Sony's i.LINK in some markets, though the underlying technology remained IEEE 1394.

The standard supports both isochronous data transfer for real-time streams and asynchronous transfer for general data, and it allows daisy-chaining up to 63 devices on a single bus. It also provides power to devices through the connector on some implementations and supports hot-plugging and plug-and-play operation. Physical connectors include 4-pin and 6-pin variants for FireWire 400 and a 9-pin connector for FireWire 800.

In terms of speed, the first widely used version, FireWire 400 (IEEE 1394a), delivers up to 400 Mbit/s. FireWire 800 (IEEE 1394b) doubles that to up to 800 Mbit/s and introduced longer cables and alternative physical layers.

FireWire was popular in the late 1990s and early 2000s for video capture and external storage but was gradually overtaken by USB and, later, Thunderbolt. Today it persists mainly as a legacy interface in certain professional cameras, audio hardware, and archival systems, with adapters available to connect to USB or other buses.

The technology remains notable for its real-time data transfer capabilities and deterministic performance, distinguishing it from many USB implementations in professional video and audio workflows.