A PCMCIA network adapter is a network interface which plugs into a PCMCIA bus slot on a computer. It may be a wireless network adapter or a wired one with an external cable for the network connection. Ethernet is the most common network technology implemented in these adapters. They are often used with laptops to upgrade built-in network interfaces to the latest technology. They may also be used with other portable computing devices that have PCMCIA slots, such as notebooks and netbooks.
PCMCIA stands for Personal Computer Memory Card International Association. It is the non-profit trade association which developed the initial standards for PCMCIA peripheral cards. In 1990, the first PCMCIA specification was released specifically for flash memory cards. This 16-bit technology was known as PC Card™ and supported two form factors, known as Type 1 and Type 2 cards. Type 3 cards were introduced in late 1992, and the technology shifted to a 32-bit bus master interface called CardBus® in 1995.
The Type 2 and Type 3 specifications provided enough functionality to support a PCMCIA network adapter. Several 10/100 Megabit per second (Mbps) Ethernet PCMCIA adapters were released by vendors during the 1990s. Network bandwidth was often limited by the bus speed of both PC Card™ and CardBus® implementations, however. Many laptops included both CardBus® and PC Card™ slots as the standards evolved. Both standards were generally supported by all of the major portable computer operating systems.
In the mid-2000s, a new PCMCIA specification emerged called ExpressCard®. This standard included benefits of both Universal Serial Bus (USB) and Peripheral Component Interconnect (PCI™) bus technology. By 2008, a large number of new laptops and notebooks were being shipped with ExpressCard® slots instead of CardBus®. Its performance increase allowed the development of a PCMCIA network adapter for Gigabit Ethernet technology. Many ExpressCard® wireless adapters have been produced as well.
Version 2.0 of the PCMCIA ExpressCard® standard was released in early 2009. This specification is no longer compatible with CardBus® or PC Card™. It is based completely on USB and PCI Express® technology, providing higher performance than Version 1.0. At least one vendor in late 2009 announced a PCMCIA network adapter for fiber-based Gigabit Ethernet. The same vendor also provides a fiber-based 100 Mbps network adapter for the ExpressCard® bus. Both standard form factors allow ExpressCard® devices to be inserted and removed at will while powered up and active.
The non-profit USB Implementers Forum (USB-IF) was significantly involved in the creation of the ExpressCard® standard. As the compliance and support organization for USB technology, it acquired PCMCIA and its technologies in early 2010. The integration of these technologies should help streamline the portable computer peripheral development process. As a result of the acquisition, the name PCMCIA will no longer be attached to products.