CIE Chapter-1: Computer Systems PDF

Chapter-1 Types and components of a computer system Topics ▪ Hardware and software ▪ Main components of a computer system ▪ Operating systems ▪ Types of computer ▪ Impact of emerging technologies  What is a computer? A computer is an electronic device that accepts data as input, processes da...

Chapter-1 Types and components of a computer system Topics ▪ Hardware and software ▪ Main components of a computer system ▪ Operating systems ▪ Types of computer ▪ Impact of emerging technologies  What is a computer? A computer is an electronic device that accepts data as input, processes data into information, stores information for future uses, and outputs the information whenever it is needed. Storage Input Process Output Hardware and software  What is Hardware? Hardware are the physical components which make up the computer system. Hardware can be either external or internal. Internal hardware devices: motherboard Processor random access memory (RAM) read-only memory (ROM) Video card/graphics card sound cards network interface card (NIC) internal storage devices: hard disk drive (HDD) and solid state drive (SSD). External hardware devices: monitor, speaker, keyboard, printer and external storage devices Motherboard The motherboard is a printed circuit board found in all computers. It allows the processor and other computer hardware to function and communicate with each other. Random access memory (RAM) Random access memory (RAM) is an internal chip where data is temporarily stored when running applications. This memory can be written to and read from. Its contents are lost when power to the computer is turned off, it is often referred to as a volatile or temporary memory. RAM stores the data, files or part of the operating system currently in use.  Read-only memory (ROM) Read-only memory (ROM) is a memory used to store information that needs to be permanent. It is often used to contain, for example, configuration data for a computer system. These chips cannot be altered and can only be read from. ROM chip is not lost even when power is turned off to the computer. They are often referred to as non-volatile memories. RAM and ROM differences BIOS (basic input/output system)  Graphics cards A graphics card allows the computer to send graphical information to a video display device such as a monitor, television or projector. It usually connects to the motherboard. Graphics cards are usually made up of: –a processing unit –memory unit (usually RAM) –a cooling mechanism (often in the form of a heat sink since these cards generate much heat) HDMI = High-Definition Multimedia Interface –connections to a display unit (monitor, television or DVI = Digital Visual Interface projector)  Sound cards A sound card is an integrated circuit board that provides a computer with the ability to produce sounds. Sound cards also allow a user to record sound input from a microphone connected to the computer, and to manipulate sounds stored on a disk. Sound cards use two basic methods to translate digital data into analogue signals (needed for speakers) ✓ FM synthesis mimics different musical instruments according to built-in formulas ✓ wavetable synthesis relies on recordings of actual instruments to produce sound  Analogue Vs digital data Digital data - binary format (0 and 1) Analogue data - physical data that changes smoothly from one value to the next  Network interface card (NIC) A network interface card (NIC) is a component that allows a computer or any other device to be connected to a network (for example, the internet); it can be wired or wireless. Each NIC is hard-coded with a unique MAC (media access control) address code.  Internal hard disk drive/solid state drive (HDD/SSD) Hard disk drives (HDD) are magnetic in nature and are one of the main methods for storing data, files (text, photos and music) and most of the system and application software. More modern computers (and all tablets) use newer storage systems that make use of solid state drive (SSD) technology and are replacing HDD in many cases. Their function is the same as HDD.  Peripherals A peripheral device is any equipment that is externally connected to the system unit such as: keyboard, printer, mouse, monitor, speakers, etc. Quiz Q1 What is the physical components of a computer? 1 Software 2 Hardware 3 Operating System 4 Application Software A N Hardware S W E R Quiz Q2 _______is volatile storage. 1 ROM 2 RAM 3 Sound card 4 Video card A N RAM S W E R Quiz Q3 _______is non-volatile storage. 1 ROM 2 RAM 3 Sound card 4 Video card A N ROM S W E R  Quiz Tick (✓) whether the following are examples of internal or external hardware devices. internal external Mouse Video card Printer NIC  Quiz Tick (✓) whether the following are examples of internal or external hardware devices. internal external Mouse ✓ Video card ✓ Printer ✓ NIC ✓ What is Software? Software is a collection of instructions (programs) 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. There are two types of software: – application software – system software  Application Software Programs that allow the user to do specific tasks. Examples of application software are: ❖ Word processor ❖ Spreadsheet ❖ Database ❖ Control and measuring software ❖ Graphics editing ❖ Video editing ❖ Audio editing ❖ Apps and applets ❖ computer-aided design (CAD) Examples of application software Word Processing: used to manipulate text documents, such as letters or reports. Provides tools for inserting photos/images, chancing text formatting, spell checking and mail merging. Spreadsheet: used for organizing and manipulating numerical data. These numbers are organized in a grid of cells. Can use formulas to carry out calculations, produce graphs and it is also used for modelling and predictions. Examples of application software Database: Helps to organize, manipulate and analyze large quantities of data. Provides the ability to carry out queries and produce reports. Also enables to add, delete and modify data in a table. Control and measuring software: are designed to allow a computer or microprocessor control devices to measure physical variables in the real world and control applications. Examples of application software Audio editing: Audio editing software allows a user to edit, manipulate and generate audio data on a computer. Video editing: Can manipulate videos to produce an edited video, by adding titles, altering sounds of frames. Also can colour correct and include transitions between clips. Examples of application software Graphics manipulation software: Allows bitmap and vector images to be manipulated. Apps and applets: also known as applications. Apps are the software which runs on mobile phones. They usually come with the phone or can be downloaded and updated. Applets are small applications that perform a single task on a device. Computer-aided design (CAD) software: This is software used to help in the creation, manipulation, modification and analysis of a drawing/design. It can be used to produce 2D or 3D diagrams. System Software Programs that allow the hardware to run properly and allow the user to communicate with the computer. Examples of system software are: ❖ Operating Systems ❖ Device Drivers ❖ Utilities ❖ Linkers ❖ Compiler Examples of system software ❖ Operating Systems: Manages computers functions including hardware devices (input/output). Also provides users with a GUI interface. ❖ Device Drivers: Allows hardware devices to run on the computer including printers, sound, graphics and network cards. ❖ Utilities: Help to manage and maintain computer resources and performance by running specific tasks. (antivirus, backup of files, disk management, disk defrafmenter) Examples of system software ❖ Linkers: Combines object files produced by a compiler into a single program. ❖ Compiler: Translates a program written in a specific language which can be understood by the computer. Quiz Q1 What are the two main categories of software? 1 System and Office 2 OS and Office 3 System and Application 4 Windows and Application A N System and Application S W E R  Quiz Tick (✓) whether the following are examples of applications software or system software. Application Software System Software Word processing Compilers Spreadsheets Database Device Drivers  Quiz Tick (✓) whether the following are examples of applications software or system software. Application Software System Software Word processing ✓ Compilers ✓ Spreadsheets ✓ Database ✓ Device Drivers ✓ Q. Describe the difference between Hardware and Software? Hardware are the physical components which make up the computer system. Software is a collection of instructions that can be ‘run’ on a computer. These instructions tell the computer what to do. Q. Describe the difference between Application and System Software? Application software are designed to allow users to complete specific tasks. For example a Word Processor is used to write a letter. System software is used to manage and maintain the computer system. An operating system such as Windows 10 is used to manage the functions of the computer system. Main components of a computer system Input devices (keyboard, mouse,..) Processor and internal memory (RAM,ROM) Output devices (printer, monitor, speakers, etc.) Backing/ secondary storage devices (hard disk drive, solid-state drive, pen drive etc.)  Main components of a computer system Central Processing Unit (CPU) Internal Hard Disk Drive (HDD) Random Access Memory (RAM) Read-Only Memory (ROM) Central processing unit ( CPU) CPU is the part of the computer that interprets and executes the commands from the computer hardware and software. It is part of the computer motherboard. CPU is referred to as a microprocessor. CPU is made up of a control unit (CU), which controls the input and output devices; (takes instructions the decodes and executes the instructions) An arithmetic and logic unit (ALU), which carries out calculations and make logical decisions; and small memory locations called registers. Input and Output devices Comparison of internal memory and backing storage Tasks for a typical Operating System (OS) Control of the operation of the input, output and storage devices. Supervising the loading, running and storage of programs Dealing with errors that occur in programs Maintaining security of the whole computer system Maintaining a computer log Allowing communication between the user and computer User Interfaces (UI) Graphical User Interface (GUI) Command Line Interface (CLI) Dialogue-based User Interface Gesture-based User Interface Graphical User Interface (GUI) GUI allows the user to interact with a computer using picture or icons. Who use GUI ? End-user who doesn't have any great knowledge of how computer works and who want to play games, run software, store photos. Graphical User Interface (GUI) Advantages: User doesn't need to learn any commands. It is more user-friendly; icons are used to present applications WIMP (Windows, Icons, Menu and Pointing Device) Post-WIMP (touch-screen, screen rotating/pinching plus WIMP) Graphical User Interface (GUI) Disadvantages: It uses more computer memory than CLI The user is limited to the icons provided on the screen Command Line Interface (CLI) CLI requires a user to type in instructions to choose options from menus, open software, and so on. Who use CLI? Programmer, System Analysts, Security Person or Technician; who needs to have direct communication with a computer to develop new software, locate errors, etc. Command Line Interface (CLI) Advantages: The user is in direct communication with the computer The user is not restricted to a number of predefined options It is possible to alter computer configuration settings. Command Line Interface (CLI) Disadvantages: The user needs to learn a number of commands to carry out basic operations. All commands need to be typed in. Each command must be typed in user the correct format. Dialogue-based user interfaces use the human voice to give commands to a computer system could also be used in the home; by using voice commands, it is possible to switch on/off lights, operate electronic equipment and so on Dialogue-based user interfaces Advantages: no need for a driver to take their hands off the steering wheel in a home, very useful for people with disabilities, because many tasks can be carried out by the spoken word only possible to use as a security feature, because voice recognition could be used to identify a person Dialogue-based user interfaces Disadvantages: still unreliable, with many commands not being recognised or needing to be repeated several times can be quite complex to set up user needs to know which commands can be used Gesture-based interfaces rely on human interaction by the moving of hands, head or even the feet Gesture recognition allows humans to interface with a computer in a more natural fashion without the need for any mechanical devices. This type of interface uses techniques known as computer vision and image processing. Gesture-based interfaces Advantages: replaces mechanical input devices no physical contact required very natural interface for a human operator no training needed to interface with the computer Gesture-based interfaces Disadvantages: possible for unintentional movement to be picked up only works fairly near to the camera or sensor may only accept a limited number of movements  Quiz The Central Processing Unit consists of three components. Tick (✓)whether the following statements refer to the ALU, the Control unit or the Main memory. ALU Control Main unit memory This is the immediate access storage This carries out the calculations This carries out logical decisions This directs the input and output flow in the CPU  Quiz Tick (✓) whether the following statements refer to a Command Line Interface (CLI) or a Graphical User Interface (GUI) CLI GUI The user has to type in every instruction The user does not need to learn any of the instructions Each instruction has to be typed in correctly The user is in direct communication with the computer Types of computer PC/desktop computers Laptop computers TabIets Phablets Smartphones  Advantages and Disadvantages of each type of computer Type Advantages Disadvantages Desktop/Personal Always connected to the mains. Not portable Computer Monitors can come in any sizes Takes up more desk space. Can be upgraded and parts easily replaced. Separate components like keyboard, Tend to have a higher specifications than laptop mouse, monitor, speakers etc. computers. Loose cables which could be trip hazards. Laptop Its portable due to small size and weight. Limited battery life. Computer Battery can be recharged. Laptops are difficult to repair and Can connect wireless to internet. upgrade. No loose cables. All components connected Can be stolen or lost. together. Some users find it difficult to use pointing device.  Advantages and Disadvantages of each type of computer Type Advantages Disadvantages Tablet Computer High definition, anti-glare display. Limited memory compared to Wireless , 3G/4G & Bluetooth connection. laptops. Data can backed up or synchronised with other Expensive to use 3G/4G internet devices. Typing can be more difficult Touch screen technology compared to a normal keyboard. Battery life longer than a mobile phone. Not all files are compatible with tablets. Smart Phone Small in size and easier to carry around. Small screens make it difficult to Can be used whilst on the move using wireless read. or 3G/4G Connectivity. Battery life is short Touch screen technology Could be misplaced or stolen Limited storage/memory compared to other types of computers. Slow data transfer rates Impact of emerging technologies 1. Artificial Intelligence (AI) biometrics 2. Robots 3. Virtual reality (VR) 4. Augmented reality 1. Artificial Intelligence (AI) Biometric AI refers to the simulation of human intelligence in machines AI biometric system learns by using AI about a person fingerprints on every scan. The system learns from the different alignments It is still able to match the fingerprints stored on a database Use: facial-recognition system, eye-recognition system Nagative impacts of AI Many job losses in a number of areas dependency on technology and the inability to carry out tasks done by robots loss of skills 2. Extended reality Extended reality (XR) refers to real and virtual combined environments » augmented reality (AR) » virtual reality (VR) » mixed reality (MR).  Virtual Reality (VR) Virtual reality is an artificial environment created by software. The user makes use of data goggles, sensor suites, data gloves, helmets to get a feeling of reality. Virtual Reality is used in all of the following areas: Military applications Business Education Real Estate Healthcare Engineering Entertainment Sports Fashion Media Heritage Scientific visualisation Augmented Reality (AR) Augmented Reality is a technology that superimposes a computer-generated image on the user’s view of the real world, thus providing a composite view. Augmented Reality (AR) is used in all of the following areas: Safety and rescue operation Healthcare Entertainment Shopping and retail