CardBus is the trade name for an advanced PC Card (also known as PCMCIA card) specification. The technology is used primarily in notebook and portable computers. The CardBus card fits in a slot like a conventional PC card.
CardBus allows for all the functions that are possible with PC cards, but with these improvements:
- Direct Memory Access (DMA) is supported.
- A 32-bit path is used for data transfer.
- The operating speed is several times greater.
- CardBus works at lower battery voltage.
A CardBus slot, and the associated software, interrogates a card when the card is first inserted in the slot. If a PC card has been inserted, the computer uses it as if the slot were a conventional PCMCIA slot. If a CardBus card has been inserted, the computer reconfigures the slot to take advantage of the enhanced operating features. For CardBus to work, the operating system must support 32-bit data paths.