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PC Cards (originally referred to as PCMCIA cards) provide a wide range of options for portable computers with PC Card slots. Most portable computers have at least one Type II PC Card slot, as seen in Figure 12.5. Many have two. Figure 12.5. A typical notebook with a Type II PC Card partly installed (top) and completely installed (bottom). Note the positions of the ejection button.
When used with MS-DOS or Windows NT 4.0, PC Cards require special software known as CSS , or Card and Socket Services (the MS-DOS and Windows NT 4.0 versions are not interchangeable). Windows 95 and newer versions have built-in support for PC Cards. Most CSS software and the built-in support in Windows 95 and later enable PC Cards to be hot-swapped; the card can be shut down, removed, and replaced with another without shutting down the system. Cards must be " stopped " before being removed or the system can become unstable and the cards or system can be damaged. PC Card Types I, II, and III and UsesThe Personal Computer Memory Card International Association gave PC Cards their original name of PCMCIA cards and is responsible for developing standards for these cards. There are three types of PC Card slots, each designed for particular types of devices:
All three types of cards have a two-row connector with 68 pins total. Most systems with PC Card slots feature two stacked Type II slots that can handle all types of cards: a single Type III card, two Type II cards, or two Type I cards at a time. Figure 12.6 compares the thicknesses of these cards. Figure 12.6. Typical Type I, Type II, and Type III PC cards and cross-sections.
PCMCIA Hardware Resource RequirementsThe CSS software used for PC Card support reserves a large area of upper memory (empty space between 640KB and 1MB) for use by PCMCIA cards. I/O port address space and IRQ usage depends on the specific card(s) used. Windows 95 and later versions configure PC Card resources automatically. CardBus and Zoomed Video (ZV)Most recent portable systems use a special high-speed type of PC Card slot known as CardBus . CardBus slots are compatible with both ordinary (16-bit) PC Cards and 32-bit CardBus cards, but CardBus cards can't be used in ordinary PC Card slots. To verify if a portable system has CardBus support, open the Windows Device Manager and the category marked PCMCIA Adapters. If a CardBus controller is listed, the portable supports CardBus. If not, you can use only 16-bit PC Cards in that system. Another variation on standard PC Card slots is Zoomed Video ( ZV ) support. Portable systems that support ZV can use PCMCIA cards with a high-speed video connector for processes such as teleconferencing or dual-display support. As with CardBus, use ZV-compatible cards only in compatible systems. However, ZV is not supported by all CardBus slots; to determine if a system with CardBus slots also supports ZV, check with the vendor. Combo PC CardsCombo PC Cards contain multiple functions and connections on a single card. The most common combination includes a modem plus Ethernet network interfacing or USB 2.0 plus IEEE-1394a interfacing. PC Card DonglesType I and Type II PC Card cards aren't thick enough to use standard RJ-11 telephone (for modem), SCSI, or RJ-45 UTP network cables. Some Type II PC Cards use a pop-out connector for telephone or network cables; others require the use of a device called a dongle a proprietary extension to the PCMCIA card that enables standard cables to be connected to the card. Figure 12.7 shows a typical 56Kbps PC Card network card with its dongle. Figure 12.7. A typical Type II PC Card 10/100 Ethernet card with the dongle used to attach the card to standard Category 5 UTP cable. Photo courtesy Linksys.
If you lose or damage the dongle, your PC Card is useless until you replace it. For this reason, many vendors are now building Type II PC Cards with a thick outer edge to support integrated 10/100 Ethernet RJ-45 or RJ-11 modem cables. Type III PC Cards are thick enough to provide standard connections, but don't fit into some systems. Inserting and Removing PC CardsInserting PC Cards into a system is a simple process (refer to Figure 12.5).
To remove the PC Card
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