The pc card and cardbus devices are being replaced by what technology?
The Personal Computer Memory Card International Association (PCMCIA) developed the PC card, a credit-card-sized memory or input/output device that plugs into a laptop computer to add functionality. Unlike desktop plugin modules, PC cards are hot-swappable, meaning they can be removed and inserted while the computer is running, without shutting it down or rebooting. This made them ideal for upgrading a laptop without opening it, and also allowed users to replace an internal component that stopped working or was obsolete.
PCMCIA cards use a standard connector, called the ExpressCard format. This standard, which was designed to eventually replace the CardBus PCMCIA standard, uses a smaller form factor, is more power efficient and provides better performance. It consists of two standard sizes, ExpressCard/34 and ExpressCard/54. The latter is the larger, at a width of 54 millimetres and height of 5 mm. The ExpressCard connector is the same on both sizes and the length of a card is 75 mm, or about half as long as a standard CardBus slot.
Like the older CardBus standard, the ExpressCard specification supports 3.3 and 5-volt cards. However, 3.3-volt cards have a protection feature that prevents them from being inserted fully into a 5 V-only slot. USB Implementers Forum (USB-IF) has a compliance program for ExpressCards that assures compatibility and interoperability. Many manufacturers have already begun to fit ExpressCard slots into new laptops, replacing the older CardBus slots. ExpressCard-to-CardBus and CardBus-to-ExpressCard adapters are available that convert the electrical connection between the two different formats, but they do not work with older non-CardBus PCMCIA cards.
