Lesson 3

How a computer works

This picture displays

the components inside an average PC. We shall now take a look at each part in more detail.

Inside a PC

Central Processor Unit. Microprocessor - “Brain” of the computer. Everything the computer does is overseen by the

CPU.

Within the CPU is:

The Control UnitThe control unit of the CPU uses electrical signals to tell the entire computer system to carry out, or execute, stored program instructions.

Like an orchestra leader, the control unit tells other parts of the computer what to do.

CPU

This is very fast storage used to hold data. It has to be fast because it connects directly to the microprocessor. There are several specific types of memory in a computer:

Random-access memory (RAM) - Used to temporarily store information that the computer is currently working with

Read-only memory (ROM) - A permanent type of memory storage used by the computer for important data that does not change

Basic input/output system (BIOS) - A type of ROM that is used by the computer to establish basic communication when the computer is first turned on

Memory

This is the main circuit board that all of the other internal components connect to. The CPU and memory are usually on the motherboard.

A sound card can be built into the motherboard or connected through PCI.

Peripheral Component Interconnect (PCI) Bus - The most common way to connect additional components to the computer, PCI uses a series of slots on the motherboard that PCI cards plug into.

Motherboard and PCI slots

Hard disk - This is large-capacity permanent storage used to hold information such as programs and documents.

Stores all your software, games, photos, mp3s, videos and saved documents.

On your computer is usually known as C: drive and sometimes D:

Modern computers have hard disk drives with memories of 200GB (gigabyte) or more. They can hold thousands of files that can all be accessed in an instant.

How much memory is

on your hard drive. Take a look!

Hard Disk Drive

These can either be built into the motherboard or plugged into PCI slots on the motherboard.

Sound card - This is used by the computer to record and play audio by converting analog sound into digital information and back again.

Graphics card - This translates image data from the computer into a format that can be displayed

by the monitor. Allows you to view movies and play games

quickly and smoothly.Can be upgraded as necessary to

keep your computer up to date.

Sounds and Graphics cards

You need input devices to tell your computer what you want it to do:

Mouse, Keyboard, Scanner, Microphone, Modem, CD ROM, DVD ROM, Disk, Memory stick, Touch screen.

You need output devices to save and view what your computer is doing/ has done for you.

Monitor, Speakers, Printer, CD, DVD, Disk, Memory Stick.

Input / Output devices

Choose 2 INPUT devices and 2 OUTPUT devices and give me a short description of how the devices work

Then give me 3 examples of what we use each of them for…

Create a blog on the school website and share the information with your friends. Please include some pictures!

Task for today