PCMCIA

Isn’t it great when you can take two relatively known abbreviations and put them together to get a third totally new one that has nothing to do with the other two? Well, anyway PCMCIA has nothing to do with PCM (Pulse Code Modulation) or the government agency. It stands for Personal Computer Memory Card International Association, which is an international standards body and trade association founded in 1989 to establish standards for Integrated Circuit cards and to promote interchangeability among mobile computers where ruggedness, low power, and small size were critical. They have defined a standard for what we’ve come to call the PCMCIA card, which is often simply referred to as a “PC Card.” Originally the PC Card was developed as a memory device that could be hot swapped in and out of any computer with a compatible slot. Like RAM, capacities and cost vary. Later, other applications such as modems, networking, audio & video recording and playback were applied to the technology. There are now many more different applications for the technology being used. PCMCIA cards come in several varieties of size now. All have the same rectangular size (85.6 by 54 millimeters), but different widths: Type I cards can be up to 3.3 mm thick, and are used primarily for adding additional ROM or RAM to a computer. Type II cards can be up to 5.5 mm thick. These cards are often used for modem and fax modem cards. Type III cards can be up to 10.5 mm thick, which is sufficiently large for portable disk drives. As with the cards, PCMCIA slots also come in three sizes: A Type I slot can hold one Type I card. A Type II slot can hold one Type II card or two Type I cards. A Type III slot can hold one Type III card or a Type I and Type II card.