电信英语翻译，请指正--1394...

1394Also called FireWire, IEEE 1394, 1394 and i.Link. 1394 is an IEEE standard for an data transport bus between a host computer and its peripherals. 1394 runs at speeds of 100, 200 and 400 Mbps, with increases planned up to 2 Gbps. A single 1394 port can support up to 63 peripherals, and a single host computer can support up to 1023 buses. The cable length can be up to 4.5 meters, although as many as 16 cables can be daisy- chained to extend the length to as much as 72 meters. A tree configuration also is acceptable. The cables comprise six conductors, and can supply up to 60 watts of power, allowing low-power peripherals to operate on a line-powered basis (i.e., without separate power). Much like USB (Universal Serial Bus), although running at much higher speeds and costing much more, 1394 supports plug-and-play on a hot-swappable basis. In other words, peripherals can be plugged and unplugged while the computer is turned on, and the computer will automatically discover and configure the link between itself and the peripheral device. Example peripherals include high-density storage devices, and high-resolution still and video cameras. 1394 supports both asynchronous and isochronous data transfer. Since 1394 is not a particularly exciting name, manufacturers have come up with their own names. For example, Apple Computer calls it FireWire. See also USB.

In writing about FireWire, Walt Mossberg of the Wall Street Journal, wrote:

FireWire, 1394, i.Link: These are three different, confusing terms for the same thing: a very fast connector on some PCs that can rapidly suck in and pump out large volumes of data from external devices, like camcorders, external hard disks and high-capacity portable music players. Apple, which helped invent the technology and has marketing in its bones, calls this connector "FireWire." The Windows PC makers use the geeky term "1394." To make matters a little more confusing, Sony calls the same connector "i.Link." This is worth buying only if you plan to import video or use a high-capacity music player like Apple's iPod.

The IEEE-1394 High Performance Serial Bus is a versatile, high-speed, and low-cost method of interconnecting a variety of personal computer peripherals and consumer electronics devices. The IEEE-1394 bus began life in 1986 as Apple Computer's alternative to the tangle of cables required to connect printers, modems, external fixed-disk drives, scanners, and other peripherals to PCs. The proposed standard (P1394) derived from Apple's original FireWire design, was accepted as an industry standard at the December 12, 1995 meeting of the Institute of Electrical and Electronics Engineers (IEEE) Standards Board. The official name is IEEE 1394-1995 Standard for a High Performance Serial Bus. The 1394 Trade Association was formed in 1994 to accelerate adoption of the Bus by personal computer and consumer electronic manufacturers. The 1394 Trade association has dubbed IEEE-1394 the MultiMedia Connection. Adaptec has licensed Apple's FireWire technology, trademark, and logo; FireWire is used interchangeably with IEEE-1394 in these pages.

The primary advantages of FireWire over other current and proposed serial buses are:

· Versatility: FireWire provides a direct digital link between up to 63 devices without the need for additional hardware, such as hubs. Digital Video (DV) camcorders, scanners, printers, videoconferencing cameras, and fixed-disk drives all share a common bus connection not only to an optional PC, but to each other as well. FireWire is a candidate for the "Home Network" standard initiated by VESA (Video Electronic Standards Association) and other industry associations.

· High speed: The present implementation of IEEE-1394 delivers 100 Mbps (Megabits per second) or 200 Mbps of data (payload) and control signals (over- head). Future versions that support 400 Mbps are in the development stage, and a 1.2 Gbps (Gigabits per second) version of IEEE-1394 has been proposed. Isochronous data transmission lets even the lowest-speed implementation support two simultaneous channels of full-motion (30-frame-per-second), "broadcast quality" video and CD-grade stereo audio.

· Low cost: The cost of the integrated circuits and connectors to implement FireWire is often less than the cost of the connectors and circuitry it replaces. FireWire uses a flexible, six-conductor cable and connectors derived from Nintendo's Gameboy to interconnect devices. (A four-conductor version of the standard cable is used to interconnect consumer audio/video components.) Use of FireWire for consumer electronics gear, such as camcorders and VCRs, will provide the high-volume market needed to achieve low-cost implementation of FireWire on PCI adapter cards and PC motherboards. Ease of installation and use: FireWire extends Plug and Play features far beyond the confines of the personal computer. When you add a new device, FireWire automatically recognizes the device; similarly, on disconnect FireWire automatically reconfigures itself. The standard FireWire cable provides up to 1.5 amps of DC power to keep remote devices "alive" even when they're powered down. You don't need a computer to take advantage of FireWire; as an example, a VCR can act as a FireWire controller for camcorders, TV sets, receiver/amplifiers, and other home theater components.

An IEEE data transport bus that supports up to 63 nodes per bus, and up to 1023 buses. The bus can be tree, daisychained or any combination. It supports both asynchronous and isochronous data. 1394 is a complementary technology with higher bandwidth (and associated cost) than Universal Serial Bus. Intel told me in summer of 1996 that it was supporting USB for most devices that attach to PC up through audio and video conferencing. Intel told that they are "supporting IEEE 1394 as the preferred interface for higher bandwidth applications such as high quality digital video editing, and connection to new digital consumer electronics equipment." according to Zayante, a company setting itself up as a testing lab for 1394 products, "The IEEE 1394 multimedia bus standard is the "convergence bus" bringing together the worlds of the PC and digital consumer electronics. It is already the digital interface of choice for consumer digital audio/video applications, providing a simple, low-cost and seamless plug-and-play interconnect for clusters of digital A/V devices, and it is being adopted for PCs and peripherals. The original specification for 1394, called IEEE 1394-1995, supported data transmission speeds of 100 to 400 Mbits/second. Most consumer electronic devices available on the market now support either 100 or 100/200 Mbits/second, meaning that plenty of headroom remained in the 1394 specification. But more devices are added to a system, and improvements in the quality of the A/V data (i.e., more pixels and more bits per pixel), lead to a need for greater bandwidth. The 1394a specification, currently in the final stages of approval (early 2000), offers efficiency improvements including support for very low power, arbitration acceleration, fast reset and suspend/resume features. The 1394b specification extends the 1394-1995 and 1394a efforts in three primary ways: It increases the speed to 800 Mbits/second and 1.6 Gbits/second, while adding the architectural infrastructure to support 3.2 Gbits/second and beyond; it specifies alternative media that allow 1394 products to be connected at distances of up to 100 meters (up from the 4.5 meters of the current specification); and it is overall more efficient, lower cost and easier to manage." See USB.

又称为FireWire，IEEE1394，1394和i.Link。1394是关于主计算机及其外围设备之间数据传输总线的IEEE标准。1394的传输速率为100Mbps，200Mbps和400Mbps，未来计划将提升至2Gbps。一个1394端口可以最多支持63个外围设备，一个主计算机可以最多支持1023根总线。其电缆长度可达4.5m，而16根电缆以菊花链连接方式，最大长度可延伸至72m。当然也可以采用树形链接。这些电缆包括6根导线，最大功率60W，允许低功率的外围设备运行在线形功率的基础（例如没有独立功率）上。很像USB（通用串行总线），尽管运行速度很快，成本却很高。1394仍支持基于热交换的即插即用方式。换句话说，在计算机开启状态下，外围设备可以随时插入，计算机将自动发现新设备，并与外围设备建立链接。外围设备包括高密度存储设备以及高分辨率静止摄像管。1394同时支持异步数据传输和同步数据传输。由于1394不是一个特别存在的名字，因此制造商已经为其单独命名。例如，苹果机称之为FireWire。参见USB。

华尔街日报的Walt Mossberg写道：

FireWire，1394，i.Link，是同一事物的三种不同的、容易混淆的名词。这里的事物指某些PC机上的一种速度很快的连接器，可以从外部设备中迅速吞吐大量数据，例如专业录像机，外部硬盘以及高容量便携式音乐播放器。苹果公司开发了这项技术并运用于其主要系统，称这种连接器为“FireWire”。Wingdows PC机制造商使用了一个令人生厌的名称“1394”。为了有所区别，索尼公司称这种连接器为“i.Link”。如果你打算输入视频或者使用诸如苹果公司的ipod高容量音乐播放器，i.Link还是很值得推荐的。

IEEE-1394高性能串行总线是一种多用途、高速率、低成本的连接方式，实现了与多种个人电脑外围设备和用户电子设备互联。IEEE-1394于1986年首次用于苹果机，解决了打印机、调制解调器、外部固定磁盘机、扫描仪以及其他外围设备与PC机连接时，电缆混乱缠绕的问题。该建议标准（P1394）源于苹果公司最初的FireWire设计，在1995年12月12日，电气和电子工程师学会（IEEE）的标准委员会会议上被接纳为一种工业标准。其官方名称为高性能串行总线IEEE1394-1995标准。1994年，1394贸易联盟成立，以加速向个人电脑和用户电子制造商推广这种总线。1394贸易联盟已经授予IEEE1394多媒体连接的称号。Adaptec为苹果公司的FireWire技术、商标和标识发放许可证。在这些方面, FireWire 与IEEE-1394是可以互换的。

与目前其它推荐的串行总线相比，FireWire基本的优点有：

●多用途：FireWire可以提供高达63个外围设备之间的数据连接，而不需要其他硬件，如HUB。数字视频（DV）摄像放像机，扫描仪、打印机、电视会议摄像机以及固定磁盘机不仅可以共享一根总线，与某一PC机连接，而且可以贡献一根总线实现彼此互联。FireWire是VESA（视频电子标准协会）以及其他行业协会发起的“家庭网络”的代表。

●高速度：目前，IEEE-1394能够实现100Mbps或200Mbps的数据（净负荷）及控制信号（过负荷）传输速率。未来标准可以支持400Mbps，目前正处于开发阶段。IEEE-1394传输速率为 1.2Gbps标准已经提上议事日程。同步数据传输甚至能够以最低速度支持两个同步全动感（每秒30帧），“广播质量”视频和CD级立体声信道。

●低成本：FireWire采用集成电路和连接器，其成本通常低于原有的电路和连接器。FireWire使用来自Nintendo的Gameboy多通用性六线电缆和连接器与设备相连接。（四线标准电缆用于连接用户音频/视频元件）。摄像放像机和VCR（盒式磁带录像机）等用户电子设备对FireWire的使用将提供一个广阔的市场，以实现FireWire在FCI适配器卡和PC机母板中低成本应用。便于开发和使用：FireWire拓展了即插即用功能，远远超出PC机的界限。在你增加一个新设备后，FireWire能够自动识别；同样，拔下该设备后，FireWire将自动进行重新配置。标准的FireWire电缆提供最高1.5A的直流电源以使远端设备处于激活状态，甚至在这些设备关闭时。你不需要使用电脑连接FireWire，例如，VCR可以代替FireWire对摄像放像机、电视机、接收机/放大器以及其他一些家用影院设备进行控制。

一根IEEE数据传输总线最多可以有1023根总线，每根总线最多可以支持63个节点。总线可以是树形结构、菊花链形结构或者其他任何结构，同时还支持同步或者异步数据。1394是一种互补技术，比通用串行总线（USB）拥有更高带宽（以及相关成本）。1996年夏天，因特尔公司告诉我，IEEE1394支持USB，用于大多数设备与PC机连接，实现电视电话会议。因特尔公司声称，他们“支持IEEE1394，将其作为专用接口，用于更高端的宽带应用，诸如高质量数字视频编辑，并且与新的数字用户电子设备相连接”。根据Zayante提供的信息，他们正在成立一个公司，专门作为1394产品测试实验室。IEEE1394多媒体总线标准是一种“聚集总线”，将PC机与数字用户电子设备联系在一起。这种总线早已经成为数字接口的一种选择，用于用户数字音频/视频应用，为一组数字A/V设备提供一个简单、低成本以及无缝的即插即用互联，同时这种总线还应用于PC机以及其他外围设备。1394的最初技术规范，称为IEEE1394-1995，支持100Mbps-400Mbps的数据传输速率。目前，市场上的大多数用户电子设备或者支持100Mbps，或者支持200Mbps，意味着1394技术规范中仍留有大量速率空间。但是太多设备加入一个系统，在A/V数据（例如更多像素，以及更多像素/比特）的质量上得到提高，从而导致对带宽的更高要求。1394a技术规范，目前正处于最后的批准阶段（最早2000年），该技术规范对有些功能进行了有效改进，包括对超低功率的支持，仲裁速度，快速复位及暂停/恢复功能。1394b技术规范在1394-1995和1394a技术规范的基础上从三个方面进一步提高功能：第一，传输速度提高到800Mbps和1.6Gbps。而增加结构中的基础设施，速度将达到3.2Gbps，甚至更高；第二，详细列举可选择的介质，允许连接最远距离可达100m的1394产品（目前的技术规范最远距离为4.5m）；第三，最有效的是，低成本且更易于管理。参见USB。