What Is a FireWire Socket?
Personal computers used to come with a bewildering array of connection ports, each necessary to connect a particular kind of peripheral. One kind of port was for printers, another kind for keyboards, another for the mouse, yet another for scanners and still a different one for modems.
In recent years, the number of necessary peripheral ports for personal computers has gone way down, as USB and FireWire ports have taken the place of the old parallel, serial, PS-2, SCSI and other such connectors. Most people are now comfortable with USB, but many people are still perplexed by FireWire.
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History
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FireWire is the best known of several brand names given to what is officially known by international standards organizations as IEEE-1394. While users of Windows PCs are less familiar with it, owners of Macintoshes know it well because Apple initiated the research that led to the development of this connection protocol. The firm has also been the most aggressive in promoting the use of FireWire on personal computers.
Apple submitted its research to the Institute of Electrical and Electronic Engineers (IEEE), and the first published FireWire specification was released in 1995. Over time, in addition to being used for personal computer peripherals, FireWire has appeared on video cameras, cable boxes, other audio-visual devices, and has even been developed for use as a networking protocol in place of Ethernet.
The idea behind FireWire is that it is simpler to adopt than such technologies as SCSI (Small Computer System Interface), widely used in professional computing environments but less well known in the consumer space--except for its use on Macintoshes during the 1980s and 1990s. It also is considered more reliable in regular use than SCSI while offering the same, or better, data transfer performance.
The presence of a FireWire port on a computer is denoted by a Y-shaped logo, which helps users to distinguish it from the three-pronged fork logo used by USB.
Two varieties of FireWire are available to computer users, presented with three different kinds of ports. FireWire as offered by Apple comes in two varieties--the original six-pin socket offered since 1999 that is now referred to as FireWire 400, and a newer variety, FireWire 800, which is distinguished by its 10-pin socket. The numbers in the name refer to their relative speed: 400 megabits per second and 800 megabits per second.
Some computers and camcorders offer FireWire with a four-pin socket. This is the Sony variation, known as i.Link, which is comparable to FireWire 400 in speed. Four-pin devices can be connected to six-pin sockets via an adapter cable, so there is no compatibility or performance penalty. The difference in the two specifications is that the two missing pins carry AC power, so four-pin devices must also be plugged into an AC outlet to operate. Six-pin devices can draw AC power from a host computer, as long as that computer also has the six-pin interface.
Adoption
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Apple first introduced FireWire ports on the 1999 Power Macintosh G3, the first of its professional line of computers to be offered in the Bondi Blue color scheme of the original iMac. FireWire, a high-speed serial communications protocol, took the place of the SCSI interface, which had been used to connect scanners, CD-ROM drives and hard disks externally to Macintoshes until then. Over the next couple of years, every Macintosh came to be equipped with FireWire, which is the firm's brand name for the protocol. Sony also was an early adopter of IEEE 1394, dubbing it i.Link, and Texas Instruments refers to it as Lynx.
Though Apple's intention was to use FireWire for the high-speed data transfer necessary to connect scanners and storage devices, FireWire's first widespread consumer use came about in the realm of consumer video. Camcorders equipped with FireWire were able to transfer their images from videotape onto computers for editing and for burning video CDs and DVDs. By equipping their computers with FireWire out of the box, Apple got an early leg up among video enthusiasts, which it expanded upon by including iMovie and iDVD as part of the iLife suite of applications that comes with every Macintosh.
Apple also used FireWire for its original webcam, the iSight, and as the connection for the original iPod. When the iPod's availability was extended to Windows users, however, USB connectivity was also made available, and over time the iPod's connectivity has migrated away from FireWire to USB.
Users of Windows PCs were not to be denied, of course. While PC makers were slow to equip their machines with FireWire ports, video enthusiasts were able to cobble together video workstations by installing FireWire ports via PCI cards and by shopping for hobbyist video applications. Over time, entry-level PCs still went without FireWire but higher-priced models, particularly those sold as "media center" PCs, are likely to offer FireWire 400 ports. -
Benefits
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FireWire, like USB, is a serial protocol that utilizes the hub-and-spoke connection model. Users of multiple FireWire devices can connect them to a hub, then connect the hub to the computer, in the same way that USB allows. Some FireWire devices also provide pass-through ports, so they can be daisy-chained as SCSI devices once were.
The major difference between FireWire and USB is that FireWire devices can operate with their own intelligence as equal peers, while USB devices have more of a master-slave relationship to their host computers. They rely on the computer's processing power to execute tasks. FireWire interfaces are designed to undertake such processing on their own.
This is seen most graphically in an Apple feature called Target Disk Mode, in which any Macintosh can be connected to any other via a FireWire cable. This feature allows one Mac to treat the other one like an additional hard drive, so that one Mac can retrieve files from another or even troubleshoot the other computer's problems. So far, Apple has not been able to implement this feature over USB.
A popular use of FireWire outside of consumer video is to attach external hard drives to personal computers. This is seen most often with Macintoshes, which are widely available with FireWire and, except for the most expensive models, do not have room for additional internal hard disks. FireWire allows users of the latest version of Mac OS X (Leopard, OS X 10.5.x) to take advantage of Time Machine, a feature that progressively backs up a Mac's hard drive to an external disk automatically--typically once an hour.
Questions
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FireWire, despite its strong performance characteristics, remains a decided second fiddle to USB as a connection protocol.
The main reason FireWire was slow to catch on was that a royalty of 25 cents per machine was initially attached to its use. Combined with the initial higher cost of interface hardware, these two factors kept the popularity of FireWire down despite its initial performance advantage over USB. In the beginning, USB was capable of only 12 megabits per second compared to FireWire's 400. It was widely assumed that USB would be mainly used for input devices (keyboard, mouse, trackball) and printers while higher performance peripherals would gravitate to FireWire.
But when USB 2.0 came along with its claimed performance of 480 megabits per second, it began to steal some of FireWire's audience. Scanners, hard drives, webcams and camcorders began adopting the faster USB, and even the advent of FireWire 800 failed to stem the defections.
Conclusion
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FireWire remains a superior data transfer protocol in many ways, particularly in the realm of external hard drives where even FireWire 400 enclosures regularly outperform USB devices. FireWire 800 extends that advantage further. For the majority of consumer computer users, however, USB is providing them with all of the functionality they need, which means FireWire is likely to become a feature relevant mainly to niche markets--the Betamax of computer ports.
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