What are PCMCIA / PC Card
PC Card (originally PCMCIA Card) is the form factor of a peripheral interface designed for laptop computers. The PC Card standard (as well as its successor Express Card) was defined and developed by a group of companies called the Personal Computer Memory Card International Association (PCMCIA). The United States computer industry created the Personal Computer Memory Card International Association to challenge the Japanese JEIDA memory card devices by offering a competing standard for memory-expansion cards. In 1991 the two standards merged as JEIDA 4.1 or PCMCIA 2.0 (PC Card).
PC Card was originally designed for computer storage expansion, but the existence of a usable general standard for notebook peripherals led to many kinds of devices being made available in this form. Typical devices included network cards, modems and hard disks. The cards were also used in early digital SLR cameras, such as the Kodak DCS 300 series.
Many notebooks in the 1990s came with two type-II slots with no barrier in between (allowing installation of two type-II cards or one, double-sized, type-III card). The PC card port has been superseded by the faster Express Card interface, but some modern portable computers still use them.
PCMCIA stands for Personal Computer Memory Card International Association, the group of companies that defined and developed the standard. While this acronym did clearly describe the original intentions of the organization's standard, it was difficult to say and remember, and was sometimes jokingly referred to as "People Can't Memorize Computer Industry Acronyms". To aid in the widespread marketing and branding of the standard, and to account for the standard's widening scope (beyond just memory cards), the association acquired the rights to the simpler term "PC Card" from IBM, and began using it, rather than "PCMCIA", from version 2 of the specification onwards.
Although the organization's name referred to memory cards, its standards were not limited to memory devices. These cards are used for wireless connectivity, modem and other functions in laptop/notebook PCs.
Card Information Structure
The Card Information Structure (CIS) is the information stored on a PC card that contains information about the formatting and organization of the data on the card. The CIS also contains information about:
The type of card
Supported power supply options
Supported power saving features
The manufacturer
Model number