What is CardBus?
CardBus is the latest enhancement to the PCMCIA 5.0 or later. PMCIA stands for Asociación Internacional de Tarjetas de Memoria. CardBus was introduced in 1995 and present in laptops from late 1997 onward. The main purpose of CardBus was to extend the existing PCMCIA bus to allow more powerful devices, and also provide support for 32 Bit I/O. CardBus includes bus mastering, which allows a controller on the bus to talk to other devices or memory without going through the CPU. CardBus also has the ability to operate at speeds up to 33MHz.
Most new slots are compatible with both CardBus and the original 16-bit PC Card devices. CardBus cards are easy to identify as they have an extra gold colored metal strip on the end of the card. This is an extra shielding required because of the faster data transfer unlike PC Card slots.