PC Cards are compact devices that meet the standards of the Personal Computer Memory Card International Association (PCMCIA). ExpressCards are even smaller devices that follow a more recent set of PCMCIA standards. Both PC Cards and ExpressCards can carry a wide variety of features and functions, including data storage, input and output connectors, and network adapters, among other things. Because the PCMCIA sets the standards and specifications for PC Cards, you may also see them described as PCMCIA cards.
Sockets for PC Cards have been a standard feature of just about every laptop computer for more than a decade. The cards that fit in those sockets allow a laptop computer owner to provide features and functions that were not built into the computer itself. Like the expansion cards that fit into PCI sockets on a desktop computer's motherboard, PC Cards can add a wide variety of services to your portable computer.
Many of the features that once required a PC Card have become standard parts of new laptop computers-these include modems that connect the computer to a telephone line, Ethernet adapters, Wi-Fi adapters, and USB ports-but plenty of other applications and services are still available on PC Cards that can either add new functions to your laptop, or provide better performance than the built-in adapters and interfaces.
Because it's easy to insert a PC Card into the socket on your laptop, they are a fast and effective way to add services that may not yet have been available when your computer was new, such as new and more advanced wireless data standards.
This chapter describes the PCMCIA standards for PC Cards and the newer ExpressCards that will eventually replace them, and explains how to use them with Windows XP.