SECTION 2 (Part B) Types And Components Of Computer Systems
2 Hardware & Software Hardware: is the physical parts of the computer system the part that you can touch and see. Hardware can be either external or internal. Examples: CPU, mouse, monitor, keyboard, motherboard, printer Software is a general term for the programs that control the computer system. There are two types of software: application and system. Examples: Windows XP, Mac OS X, Microsoft Word, Microsoft Excel
3 Internal Hardware Devices Processor Motherboard Random Access Memory (RAM) Read Only Memory (ROM) Video Cards Sound Cards Internal Hard Disk Drives
4 External Hardware Devices Monitors Keyboards Mouse Printers In general all the input and output devices and the external storage devices
5 Software Software System Software Application Software 5
6 Software Operating System: Programs that allow the hardware to run properly and allow the user to communicate with the computer Examples: Windows Vista, Linux, Mac OS X, Unix, Windows 7 Application: Programs that allow the user to do specific tasks Examples: Word, Excel, Internet Explorer, Skype, PowerPoint
7 An operating system is a special piece of software that manages the general operation of a computer system: It provides a user interface so that we can interact with the computer It manages applications that are running on the computer, starting them when the user requests, and stopping them when they are no longer needed It manages files, helping us save our work, organize our files, find files that we have saved and load files It manages the computers memory, deciding what should be loaded into memory and what should be removed It looks after computer security, preventing unauthorized access to the system It manages the computer s input and output hardware such as printers, etc.
8 Operating Systems Useless It works! Useful! Examples Windows XP Windows Vista Windows 7 Linux Unix Mac OS X MS-DOS 8
Differences between hardware and software 9 Computer hardware is the physical components that 9 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. +
10 Main Components of Computer Systems Input Devices Data Central Processing Unit Data Output Devices D a t a 10 Main / Internal Memory
11 Main Components of Computer Systems Central Processing Unit / Processor Internal Hard Disk Drive Random Access Memory (RAM) Read Only Memory (ROM) Input and Output Devices Seondary / Backing Storage
12 Central Processing Unit (CPU) / Processor CPU is the brain of the computer, where all the data is processed, and it is responsible for running computer programs and responding to user input. The speed of a CPU is measured in Hertz (Hz). CPUs usually plug into a large socket on the main circuit board (the motherboard) of a computer. The CPU is made up of: a control unit, which controls the input and output devices an arithmetic and logic unit (ALU), which carries out calculations and makes logical decisions; and the immediate access store (RAM).
13 Internal Hard Disk Drive It is the computer s main internal storage This is where the applications software, disk operating system and files (for example, text, photos or music) are stored The main advantage of these storage devices is the fast data transfer/access times and their large capacity to store data The storage capacity of memory is measured in Bytes.
14 Random Access Memory (RAM) Is the part of the computer where data is temporarily stored when running applications RAM is a volatile storage device. This means that if the computer s power is turned off the contents of RAM will disappear and lost. When a computer is in use, its RAM will contain 1. The operating system software 2. The application software currently being used 3. Any data that is being processed
15 Read Only Memory (ROM) ROM is used in most computers to hold a small, special piece of software: the 'boot up' program. This software runs when the computer is switched on or 'boots up'. The software checks the computer s hardware and then loads the operating system. ROM is non-volatile storage. This means that the data it contains is never lost, even if the power is switched off. This 'boot up' software is known as the BIOS (Basic Input Output System)
16 Peripheral Devices Peripheral devices are hardware items that are connected internally or externally to a computer and allow data to be passed in and out of the computer. They are usually categorized into input devices, output devices and storage devices.
17 17 Input Devices Devices that pass data into the computer are known as input devices. There are two categories: Manual & Automatic Input devices For example: 17 1. Keyboards 2. Numeric keypads 3. Mouse 4. Tracker ball 5. Joysticks 6. Touch screens 7. Web cams 8. Light pens 9. Microphones 10. Sensors 11. Chip readers 12. Magnetic stripe readers Input devices take information from the outside world, convert them into data and then send this data into the computer for processing.
18 Output Devices Devices that take out data from the computer are known as output devices. For example: 1. Monitors 2. Multimedia Projector 3. Graph Plotter 4. Speakers 5. Laser Printer 6. Inkjet Printer 7. Dot Matrix Printer 8. Control Devices (Motors, Buzzers, Heaters, Light/Lamps) They all take information from the computer and convert it into real world things (images, paper hardcopy, sound).
19 Secondary Backing Storage Devices Secondary storage (sometimes called backing storage) is the name for all of the devices (apart from ROM and RAM) that can store data in a computer system. Secondary storage is non-volatile, so data that is stored on these devices remains there safely. For Example: 1. Hard Drive 2. CD-ROM 3. Floppy disk 4. USB memory stick e.g. If we are typing a letter using Word, the data for the letter is in RAM (if the power goes off we lose it all). When we save the letter, the data is copied from RAM to a storage device such as a memory stick or hard-drive for safe-keeping.
20 Operating Systems An operating system is a software program that manages computer resources. Operating systems allow components to communicate with each other and enables the computer to run software applications 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. Types of Operating System Interfaces Command Line Interface (CLI) Graphical User Interface (GUI) Touchscreen Interface
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22 Command Line Interface (CLI) A command line interface is an older style operating system where users type in commands using keyboard. Command Line Interface's do not make use of images, icons or graphics. All the users can see is a plain black screen like the one to the right. There is no use for a mouse 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:\
23 Graphical User Interface (GUI) It allows the user to interact with a computer using pictures or icons (symbols) rather than having to type in a number of commands WIMP (windows icons menu and pointing device) 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
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27 Types of Computer PC/ Desktop Computers Laptop Computers Tablets Smartphones Smart watches Mainframe Computers
28 Personal Computer (Desktop PC) Personal computers are usually found in the home and in schools/business offices. Personal computers are made up of input devices, output devices and storage devices all held together within a base unit which houses all the hardware components that make the PC work. Personal computers can be used as either: Standalone computer (used by one person at a time) Networked computer (part of a group of connected computers)
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Laptop 30 Laptops are portable computers and are small enough to sit on your lap. Modern laptops are generally almost as powerful as a desktop PC and are used for similar tasks and purposes such as multimedia, school work, Internet access etc. They have LCD screens (Liquid Crystal Display) which use low-power. This helps increase the run-time of a laptop's battery.
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Tablets 32 Tablets are small, hand-held, mobile computers that share a lot of the features of desktop PC's and laptops. Tablets use touchscreens instead of a mouse and keyboard to input commands. Tablets usually come with 'physical buttons' which are used to switch the computer on/off and alter volume. Tablets can be used for similar functions as a desktop PC and laptop. For example: Multimedia (movies, music, games etc) Internet access (web browsing, emailing, Skype etc) Using application software (word processing, spreadsheets etc)
33 Tablets Some tablets also have slots for SIM cards (subscriber identity module) which allows the device to make phone calls just like on a mobile phone. Using SIM cards can also give tablets the ability to access 3G and 4G technology. This allows the tablet to access the Internet even in areas without wireless networks.
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Smartphones 35 Early mobile phones could only make voice calls and send text messages. Modern smart phones (like iphones) have much more functionality and can perform similar functions to desktop PC's and laptops. Smart phones often have the following features built-in: Digital cameras (both video and images) Sound recorders Calendars and Organisers GPS satellite navigation Wireless connectivity (to the Internet and other networks) Bluetooth connectivity (to connect to devices close by) Word processing and spreadsheet creation facilities, etc
36 Smartphones Smart phones usually have touchscreens and either use on-screen keyboards or have a very small physical keyboard. The uses of smart phones are very similar to that of tablets. For example: Internet access (both on wireless and using 3G/4G) Multimedia (video, games, music etc) Running apps Making phone calls and messages etc
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38 Smart watches Essentially allow users to wear a mini-computer on their wrists They use touch screen technology but also have the ability to link to smartphones using Bluetooth technology. Smart watches have the following functions: internet connectivity (browsing, searches, sending emails and so on) ability to make and take phone calls messaging via text or video weather forecasts fitness and health-monitoring capability GPS (finding your location and, using satnav, directions to other locations)
39 Mainframe Computers Is a large computer, often used by large businesses, in government offices, or by universities. Powerful - they can process vast amounts of data, very quickly Large - they are often kept in special, air-conditioned rooms Multi-user - they allow several users (sometimes hundreds) to use the computer at the same time, connected via remote terminals (screens and keyboards)