Chapter 1: Types and Components of Computer SystemsRevision

1.1 Hardware and SoftwareDefine hardware, giving examples

What is Hardware?Hardware is the physical parts of the computer system – the parts that you can touch and see.

A motherboard, a CPU, a keyboard and a monitor are all items of hardware.

1.1 Hardware and SoftwareWhat is Hardware?

Hardware is the physical parts of the computer system – the parts that you can touch and see.

A motherboard, a CPU, a keyboard and a monitor are all items of hardware.

1.1 Hardware and SoftwareDefine software, giving examples

What is Software?

Software is a collection of instructions that can be ‘run’ on a computer. These instructions tell the computer what to do.

Software is not a physical thing (but it can of course be stored on a physical medium such as a CD-ROM), it is just a bunch of codes.

Examples of Operating Systems (system software) - Windows 8 or Mac OS XExamples of Applications Software - Microsoft Word or Adobe Photoshop

1.1 Hardware and SoftwareDefine software, giving examples

Hardware drivers are a piece of software that enable the hardware to be installed and run properly on a computer

If the drivers are not installed the hardware will fail to run

1.1 Hardware and SoftwareSoftware Drivers

1.1 Hardware and SoftwareThe Difference Between Hardware and Software

Computer hardware is the physical components that make up the computer system. Hardware is useless without software to run on it.

Software is instructions that tell computer hardware what to do. Software is useless unless there is hardware to run it on.

For a computer system to be useful it has to consist of both hardware and software.Imaging:

An iPhone without IOSA PC without Windows

1.1 Hardware and SoftwareMain Computer Components

Central Processing Unit (CPU)

The CPU is the 'brain' of the computer. It is the device that carries out software instructions.

A motherboard is a printed circuit board found in many modern computer which holds many of the crucial components of the system.

Motherboard

Memory Any data or instructions that are to be processed by the CPU must be placed into main memory.

Hard driveA hard disk drive is a hardware device that's used to store information like software and files.

1.1 Hardware and SoftwareMain Computer Components

Graphics Card

Sound Card

A sound card is a device that attaches to the motherboard to enable the computer to input, process, and deliver sound

A graphics card is a device that attaches to the motherboard to enable the computer to process and display graphics.

Power SupplyThe component that supplies power to a computer.

CD/DVD Drive

An optical disc drive that reads and writes all common CD and DVD formats.

1.2 The main components of computer systemsCPU (Central Processing Unit)

• The CPU is the 'brain' of the computer.

• It is where all the searching, sorting, calculating and decision making takes place.

• The speed of the CPU is measured in Gigahertz (GHz).

• A 1 GHz CPU can carry out 1 billion instructions per second!

• Intel and AMD are the most popular CPU brands.

1.2 The main components of computer systemsCPU Fan

• When the CPU is running powerful programs doing billions of calculations a second it can get very hot.

• It therefor needs a fan to help it cool down

1.2 The main components of computer systemsMain Memory (primary storage)

• Also known as Internal Memory, Main Memory, primary memory and primary storage

• Main memory is a storage location that holds memory while the computer is running

• It’s the fastest memory in your computer and is used to store data while its being used

• RAM is an example of primary storage

1.2 The main components of computer systemsMain Memory (primary storage)

Programs are installed on the computers hard drive (secondary storage)

When a program is running the CPU uses RAM memory to run the program

1.2 The main components of computer systemsRAM (Random Access Memory)

• RAM stands for Random Access Memory

• RAM is the part of the computer that temporarily stores the instructions that the computer is running, and the data it is processing.

• RAM is volatile which means that when the computer is turned off all data is lost

1.2 The main components of computer systemsROM (Read Only Memory)

• ROM stands for Read Only Memory

• ROM is a built in memory that can not be changed (it can only be read from)

• ROM normally holds the ‘boot up’ program to a computer – without it the computer wouldn’t know what to do when on button is switched on

• ROM is non-volatile memory which means that memory is not lost when computer is turned off.

1.2 The main components of computer systemsBacking Storage

Backing storage is also known as secondary storage

Backing Storage is normally used to describe other storage devices aside from Main Memory (RAM or ROM)

Backing storage is non-volatile which means that data is not lost when computer is turned off.

Backing storage is used to store data for a long time (data can be read from and written to)

Types and Components of Computer SystemsPeripheral Devices

Technically, a computer need only be made up of a CPU and some RAM. But a computer like this would not be much use to anybody – other devices need to be connected to allow data to be passed in and out of the computer.

The general name for these extra devices is ‘peripheral devices’. They are usually categorised into input devices, output devices and storage devices.

Input Output Storage

Types and Components of Computer SystemsInput Device

• An input device is a device that can pass date into the computer

• They all take information from the outside world (key presses, hand movements, images), convert them into data and then send this data into the computer for processing.

Types and Components of Computer SystemsOutput Devices

• Devices that take data from the computer are known as output devices.

• They all take information from the computer and convert it into real world things (images, paper hardcopy, sound).

1.3 Operating systemsOperating Systems

An operating system is a special piece of software that manages the general operation of a computer system:

Task Explanation

Provides User Interface

Helps the user interact with the computer through Windows, Icons, menus and pointers

Manages Applications Starting and stopping applications when user requests

Manages Files Helping save, organise, find and delete files

Manages computer memory

Decided what should be loaded and deleted from memory

Computer security Prevents unauthorised access to a system

Manages peripherals Manages input and out devices such as printers

1.3 Operating systemsUser Interfaces

Graphical User Interface (GUI) Command Line Interface (CLI)

A GUI is an interface built around visual (graphical) things:Windows are regions of the screen used to display information• Icons are small pictures that are used to represent

folders, software, etc.• Menus are lists of options the user can select from

A pointer is an arrow that can be moved around the screen and is used to select things

• Windows XP is an example of an operating system with a GUI.

GUIs are quite easy to use due to the visual nature of the interface – the user has lots of visual clues as to what things do.

The user would see nothing but a black screen. They would have to type a command to make anything happen.

e.g. To copy a text file called NOTES from a floppy disc to the hard drive the user would have to type:

COPY A:\NOTES.TXT C:\

The user would have to learn a whole set of strange commands so that they could make use of the computer system. Plus it was not very interesting look at – no visual clues to tell you what to do next.

This meant computers used to be quite difficult to use, so this type of interface is only really suitable for expert users.

The system that people use to interact with a computer (to give it commands, to see the results of those commands, etc.) is known as the user interface.

1.3 Operating systemsIdentify the following GUI’s

Examples of GUI

1.3 Operating systemsGraphical User Interface

GUI is an interface built around graphics. • Windows – areas for displaying

information

• Icons -small images used to represent files/folders or software

• Menus - lists of options users can select from

• Pointers – arrow that can be moved around the screen to select items

WIMP

GUI’s are easier to use that CLI’s as you don’t have to be an expert user

1.3 Operating systemsCommand Line Interface (CLI)

• Many years ago computers were not powerful enough to process colourful graphics.

• Users would therefore only see a black screen in front of them

• They would have to type commands to make something happen

• Users would have to learn a whole set of commands which meant that computers were difficult to use and suitable for expert users

Very difficult to use and really only suitable for expert users

1.4 Types of computerPersonal Computer (PC) or Desktop

• The early 1980s saw a revolution in computing: The creation of computers that were small enough to fit on a desk, and cheap enough that everyone could have their own, personal computer, instead of having to share access to a mainframe.

• These computers came to be known as desktop computers, or personal computers (PCs).

• A typical PC contained the same basic components as a mainframe computer (CPU, RAM, storage, etc.) but at a fraction of the size and cost.

1.4 Types of computerLaptop Computer

• A 'laptop' computer is a light, compact and portable PC.

• Laptops contain a rechargeable battery so that they can be used even when not plugged in to a mains power supply. They also have a built-in LCD monitor.

• To make them as portable as possible, most laptops try to avoid any sort of cable or wire. Instead of a mouse, a touchpad is used. Instead of a wired connection to a network or printer, 'wireless' radio connections are used.

1.4 Types of computerTablet Computer

• Thanks to popular tablets like the iPad, the whole idea of what a tablet PC is has changed.

• Modern tablets are thin and light with touchscreens that respond to finger touch--no stylus or keyboard needed.

• They connect to the internet via Wi-Fi or mobile broadband 3G or 4G networks, just like smartphones.

• Some tablets make getting work done on the go easier, while others prioritize entertainment. The best tablets balance long battery life with speedy performance.

1.4 Types of computerSmart Phone

A smartphone is a device that lets you make telephone calls, but also adds in features that, in the past, you would have found only on a personal digital assistant or a computer.

Key Smartphone Features

Operating System: In general, a smartphone will be based on an operating system that allows it to run applications.

Apps: While almost all cell phones include basic applications (additional apps can be downloaded)

Web Access: More smartphones can access the Web at higher speeds, thanks to the growth of 4G and 3G data networks. Access to the internet can allow users to:Browse, stream, download, communicate and share files.