Major Hardware Components and Their Functionality
CPU executes instructions stored in memory devices.
During the boot process, the CPU fetches instructions from the permanent memory devices, ROM and CMOS.
ROM is read-only memory that stores instructions needed to start up the computer.
CMOS contains system configuration data.
Once the computer is booted, RAM is used to load the rest of the instructions to be executed by the CPU.
Data from storage devices such as the CD-ROM drive and the hard drive are passed through the disk controller. Data can also be stored on hard disk or CD.
Data in the hardware system passes through buses. The buses are the communication channels among components in the system unit.
Peripheral devices such as the keyboard, mouse, joystick, printer, speakers, and microphone are connected to the computer via ports typically in the back of a system unit.
Expansion cards can be plugged into the expansion slots of the computer to extend the functionality of a computer.