The PC Card bus (PCMCIA)

PC Card Bus Introduction

The PC Card bus was developed in 1989 by the PCMCIA (Personal Computer Memory Card International Association, which is the name sometimes given to the bus) consortium in order to extend current peripheral equipment connectivity on mobile computers.

Technical Characteristics

PCMCIA peripheral equipment comes in the shape of a credit card (54mm by 85 mm) and has a 68-pin connector.

PCMCIA peripheral equipment size

There are three form factors that correspond to three standard thicknesses:

TypeWidth (mm)Length (mm)Thickness (mm)
Type I PC Card54853.3
Type II PC Card54855.0
Type III PC Card548510.5

Type I cards are generally used as memory expansion cards. Type II cards are generally for peripheral communication equipment (modem, network card, wireless network card) and small hard drives. Type III cards, much thicker, are generally used for peripheral equipment with mechanical elements (large capacity hard drives).


Starting in 1995, the CardBus standard (sometimes called 32-bit PC Card) appeared, allowing 32-bit data transfer at a speed of 33 MHz with a 3V charge (versus 5.5 for PCMCIA).

Ask a question
CCM is a leading international tech website. Our content is written in collaboration with IT experts, under the direction of Jean-François Pillou, founder of CCM reaches more than 50 million unique visitors per month and is available in 11 languages.


This document, titled « The PC Card bus (PCMCIA) », is available under the Creative Commons license. Any copy, reuse, or modification of the content should be sufficiently credited to CCM (