I
n the early days of the PC, very little support was included in the motherboard for
peripheral devices. The controllers and adapters used to drive and interface any pe-
ripheral devices, such as the monitor, hard disk, floppy disk, and so on, had to be
added to the motherboard’s circuitry throughexpansion cards, which are also known as
expansion boards, adapters, add-in cards, and daughterboards. These days, much of the
support for peripherals is built into the motherboard, but on older PCs, adding a new
peripheral device usually means adding an expansion card.
Expansion cards are also added to the very latest PCs, often to upgrade the quality or
speed of the PC’s graphics and sound or to connect to nearby computers or printers or the
outside world. Figure 11-1 shows a typical expansion card. Expansion cards can be used
to improve the video performance, add or improve the sound system, add additional or
new ports or connectors, provide a network connection, and many other functions. They
can add a completely new function or capability or augment or replace an existing one.
It may sound obvious, but expansion cards are inserted into expansion slots. These slots
are located on the PC’s motherboard and are receptacles that provide an interconnection for(^220) PC Hardware: A Beginner’s Guide
Figure 11-1. A network interface card is a type of expansion card used to connect a PC
to a network