Chapter 8. Expansion Buses

In an effort to give notebook computers the kind of expandability users have grown used to in desktop systems, the Personal Computer Memory Card International Association (PCMCIA) has established several standards for credit card “size expansion boards that fit into small slots found in laptop and notebook computers. PCMCIA was founded in 1989 as a non-profit trade association with more than 85 member companies worldwide, to establish technical standards for PC Card technology. The development and evolution of the PCMCIA's PC Card interface standard has proven to be a successful feat of engineering in a market full of proprietary designs.

The words "Memory Card" in the PCMCIA name allude to the original 1.0 specification it released in September 1990, which was for memory cards only. The 2.0 release that came in September 1991 added support for I/O (input/output) cards as well. Subsequent releases have enhanced the standard further, adding higher performance modes, lower power consumption, and greater compatibility. The current PC Card Standard (Release 8.0) has added many capabilities, features, and functions, and has grown well beyond its simple memory card origins.