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Nhanh SCSI: Các tính năng tốc độ truyền dữ liệu lên đến 10Mbps trên các hệ thống cáp SCSI-1 8-bit. Wide SCSI: Cung cấp cho 16-bit và cấu trúc 32-bit bus SCSI. nhưng SCSI-1 thiết bị chỉ có thể hoạt động ở tốc độ ban đầu của họ. | Remember The IEEE 1394 bus is similar to the USB interface see Connecting with USB earlier in the chapter in that it is a high-speed Plug and Play bus that eliminates the need for devices to have their own power supplies. But it goes USB one better by providing for isochronous or real-time data transfers in which data is transferred within certain time constraints such as multimedia data where the audio and video must arrive together. An IEEE 1394 port supports up to 63 external devices and is considered the link between PCs and consumer electronics. For example through a 1394 port a digital video camera can be used to both capture video content and then playback the video after it s been edited on the PC. The primary difference between 1394 and USB is that 1394 is faster and generally more expensive. Therefore 1394 is used mainly for those devices such as a video camera that require larger data transfers in a shorter time period such as a digital video camera whereas USB is used for the majority of other peripheral devices. But another and perhaps more dramatic difference is that 1394 is a peer-to-peer interface that doesn t require a host system. Although heresy to PC repair professionals a 1394 bus can exist quite well with no PC at all. A video camera can easily support and power several devices on a common interface as shown in Figure 11-4 . Figure 11-4 A sample IEEE 1394 bus. Applications for 1394 Some applications that you may see for the 1394 standard involve connecting high-end peripheral devices to portable and desktop PCs. The devices that would use the 1394 connection to the PC are audio visual and multimedia capture and playback devices video conferencing printers scanners external RAID storage devices and consumer electronics like digital camcorders VCRs DVD units and set-top boxes. Software support for 1394 Most current operating systems including Windows 98 and 2000 support IEEE 1394 but typically only if the device controller is an OHCI Open Host .