PCMCIA
PCMCIA, which stands for Personal Computer Memory Card International Association, is an obsolete standard for credit card-sized expansion cards used primarily in laptop computers in the 1990s and early 2000s. The cards were later renamed PC Cards to simplify the difficult-to-remember acronym.
PC Cards were designed to give laptops the ability to add functionality through a small, removable form factor.
A variety of devices were available, including: Memory expansion cards, Modems, Ethernet network cards, Wireless network adapters, External hard drives, and
SCSI adapters.
The PCMCIA standard defined three types of cards based on thickness:
Type I: The thinnest cards (3.3 mm), typically used for memory expansion.
Type II: The most common type (5.0 mm), used for I/O devices like modems and network cards.
Type III: The thickest cards (10.5 mm), designed to house miniature hard drives.