What do the various levels of PCMCIA cards mean?
To allow manufacturers to add functions and technologies in the PC Card form factor, PCMCIA has defined three PC Card types. Type I, II, and III cards all look like credit cards from the top, with the same length and width, but with different thicknesses. All three have a 3.3-mm thick guide rail around their edges and connector ends, but Type II and III cards have bubbles or canopies that are 5 mm (equal to a stack of about 6 credit cards) and 10.5 mm thick respectively. The guide rails allow the thinner cards to be installed in thicker slots (for example, Type II cards fit in Type II and III slots, Type I cards fit in any Type slot). A Type I PC Card is 3.3 mm thick and is commonly used for system memory products. Type II PC Cards are 5 mm thick to accommodate applications that require slightly more room for components such as flash cards, fax/modem, and network cards. Type III PC Cards are 10.5 mm thick to accommodate high-functionality products such as rotating disk drives and wirel
