Interfaces for Removable-Media Drives
| In addition to choosing a type of device, you must choose which type of interface is ideally suited for connecting it to your PC. Several connection options are available for various types of removable-media drives. Table 10.1 provides a cross-reference to current types of removable-media drives and the interfaces they support.
The most common interface (and one of the fastest) for internally mounted drives is the same AT Attachment (ATA) interface used for most hard drives. SCSI interfacing is as fast or even faster for use with either internal or external drives but requires adding an interface card to most systems. Most high-end tape backups require a SCSI interface. The most common external interface is now the USB port, which has largely replaced the venerable parallel port for printing as well as for interfacing low-cost external drives and other types of I/O devices. The USB port is available on virtually all recent PCs (both desktop and notebook models), can be hot-swapped, and is supported by Windows 98 and later. For small-capacity (under 300MB) removable-media devices, the performance of USB 1.1 (12Mbps) is adequate, but larger removable-media devices should be connected to the faster USB 2.0 port (480Mbps) or the 400Mbps IEEE 1394a (FireWire/i.LINK) port if possible. Most flash memory devices must be connected either directly to a USB port or to a card reader, which usually plugs into a USB port. Some can be plugged in to a CardBus adapter on laptop computers, and some recent laptop computers have integrated slots for some types of flash memory cards (primarily SD or MMC). Many of the latest flash memory card readers and keychain USB drives now support Hi-Speed USB (USB 2.0), so if you're not satisfied with the speed of data transfer from USB 1.1 devices and your system supports Hi-Speed USB, use Hi-Speed USB storage devices. Older interfaces such as the parallel port and PC Card (for notebook computers) are still used on some devices but have limited performance. These are recommended only for systems that don't support USB, such as those still running Windows 95 or Windows NT. Some external removable-media drives allow you to interchange interfaces to enable a single drive to work with a variety of systems. Note Although late versions of Windows 95 ("Win95C" or OSR2.1 and above) also have USB drivers, many developers of USB devices do not support their use with Windows 95. For reliable results and manufacturer support, use Windows 98 or newer. Hi-Speed USB ports can be added to desktop systems that have an available PCI slot and to notebook computers that have an available CardBus (32-bit PC Card) slot. As you will see in the following sections, most removable-media drives are available in two or more of these interface types, allowing you to choose the best interface option for your needs. Note Connecting or installing removable-media drives is similar to connecting and installing other internal and external peripherals. The external USB, IEEE 1394, or parallel port drives are the simplest of the available interfaces, requiring only a special cable that comes with the drive and installation of special software drivers. See the instructions that come with each drive for the specifics of its installation. Refer to Chapter 7, "The ATA/IDE Interface," and Chapter 15, "I/O Interfaces from Serial and Parallel to IEEE 1394 and USB," for details on how these interfaces operate. For information on the SCSI interface, refer to the PDF version of Chapter 8 in Upgrading and Repairing PCs, 16th Edition, included on the disc packaged with this book. The following sections provide details on each of the removable-media drive types discussed in this section, starting with the floppy disk drive. |
EAN: 2147483647
Pages: 283