A PC Card (previously known as a PCMCIA card) is a credit card-size memory or I/O device that fits into a personal computer, usually a notebook or laptop computer. Probably the most common use of a PC Card is the telecommunications modem for notebook computers. There are 16-binary digit and 32-bit (CardBus) varieties of PC Cards. Another type of PC card is the ZV port Card.
The PC Card is based on standards published by the Personal Computer Memory Card International Association (PCMCIA), an industry group organized in 1989 to promote standards for both memory and I/O integrated circuit card. The PCMCIA 2.1 Standard was published in 1993. As a result, PC users can be assured of standard attachments for any peripheral device that follows the standard.
A PC Card has a 68-pin connector that connects into a slot in the PC. There are three sizes (or "types") of PC Cards:
| Type | Thickness (mm) | Typical use |
|---|---|---|
| I | 3.3 | Memory |
| II | 5.0 | Modems, LANs. SCSI, sound |
| III | 10.5 | ATA hard drive |
The Type I and II cards work in a Type III slot and a Type I card will work in a Type II slot. (On the other hand, the thicker cards can't be fitted into the slots for the thinner cards.)
The PCMCIA standard is most commonly applied to portable PCs but it can also be used on desktop computers. The PC Card is not to be confused with another credit-size electronic card, the smart card.