Lecture 2: Components of Computers PDF

Lecture 2  During the Last Lecture … To learn about the evolution of computing To recount the important milestones and the key events To learn about the steps that took us from Babbage’s idea of the Analytical Engine to today’s ultra-smart hand held compute...

Lecture 2  During the Last Lecture … To learn about the evolution of computing To recount the important milestones and the key events To learn about the steps that took us from Babbage’s idea of the Analytical Engine to today’s ultra-smart hand held computers  Today’s Goal To learn about the basic concept of a computer system What is Computer  Definition No 1 Computer is an electronic device which takes some input, process it, and produce output.  Definition No 2 Electronic machine operating under the control of instructions stored in its own memory Accepts Data (Input) Manipulates Data according to specified rules (Process) Produces Data (Output) Stores Results (for Future use) What is Data Data is a collection of raw unprocessed facts, figures, and symbols What is Information Information is data that is organized, meaningful, and useful. To process data into information, a computer uses hardware and software  What is Hardware Hardware is the electric, electronic, and mechanical equipment that makes up a computer.  What is Software Software is the series of instructions that tells the hardware how to perform tasks.  PARTS OF COMPUTER According to above definition we can divide computer functionality in to three main parts. Input Output Process PARTS OF COMPUTER Input Proce Outpu ss t  What is Input Input is any data or instructions entered to the computer. Input can be in the form of audio, video, graphics and animations and instructions. Instructions can be Programs Commands User response  Programs Program tells a computer what to do and how to do? These are written instructions in some specific language.  Commands Command causes a program to perform a specific action. Like Ctrl + S for saving a Ms. Word Document.  User Response A user response is an action which is or can be done by answering any question from computer like You want to save that file? User have two options Yes or No, that is depend on the user what to response.  What is Output Output is the data that has been processed in to useful form. The computer takes the input from user process it and produced output. Output also can be text, Audio, Video, graphics and animations. Output can be in two forms Soft Copy Hard Copy  Soft Copy When you are writing a document, playing a game, watching a video clip, or reading the latest news. Soft copy is what you see on the monitor(Screen). Soft copy is temporary; after you have finished with it, there is nothing solid to hold. You can, however, transfer soft copy to a disk to transport it  Hard Copy Hard copy can be touched and carried. Hard copy is usually some form of paper output. It is especially helpful if you need to have a colleague look at your work or you need to give your work to a supervisor or teacher. COMPONENTS OF COMPUTER  COMPONENTS OF COMPUTER There are three main Components of computer. 1. Input devices 2. CPU 3. Output Devices Input CPU Output Devices Devices  INFORMATION PROCESS CYCLE Computer process data (input) into information (output).A Computer often holds data, information, and instruction in storage for future use. The series of input, process, output and storage activities is known as the information process cycle. INFORMATION PROCESS CYCLE Data Information Inpu CPU Outpu t t Instruction Storage Medium  WHAT IS DATA Definition: “Raw facts, figures, events and transactions are called data” Example: Researchers who conduct market research survey might ask member of the public to complete questionnaires about a product or a service. These completed questionnaires are data. NADRA prepared CNIC of Pakistanis by collecting data of people who belongs to Pakistan. Some candidates want to take admission in university they will fill admission forms. Above all are unprocessed and unprepared which is needed to process and work more.  WHAT IS INFORMATION DEFINATION: “Meaning full data is called information” “Processed data is called information”  Detail Example Some candidates want to take admission so they will fill an admission form containing data about their selves. When this data is organized and arranged by eligibility criteria and admission rules a merit list will be formulated. This merit list is in the form of information of certain students which are eligible for admission.  Detail Example Data Name: Ali, Ayesha, Ahmad, Munir Marks:10,5,2,8 Process Merit calculation If marks >=5 candidate is eligible Merit List Sr No Name Marks 1 Ali 10 2 Ayesha 05 Information 3 Munir 08 Input Devices  WHAT ARE INPUT DEVICES Any hardware component used to enter data, programs, commands, and user responses into a computer. Examples  Key board  Mouse  Digital Camera  Webcam  Scanner etc. WHAT ARE INPUT DEVICES  WHAT IS HARDWARE The term hardware refers to the physical parts of the computer. Computer hardware is versatile what it does depends on the computer program you use. All components which are tangible (touchable) are called Hardware. Examples: Mic, Keyboard, Hard Disk, Scanner, Printer etc.  WHAT IS SOFTWARE Software is the set of instructions (also called a program) that guides the hardware through its job. That tells the computer what to do? And how to do it? All components which are non tangible (Not Touchable) are called software. Examples: Ms Office, Operating Systems, Adobe photo shop etc  WHAT IS KEYBOARD “Keyboard is an input device, that contain keys user press to enter data or instructions in to the computer”. You enter most input data into the computer by using a keyboard. This input method is similar to typing on a typewriter.  KEYS OF KEYBOARD Computer keyboards include keys that are designed to perform specific tasks. These keys enable the user to perform complex tasks easily when using the application. For example, many applications use a function key to access online help for the user.  KEYS OF KEYBOARD Keyboard keys consist of  Alphabetic keys  Numerical keys  Symbols  Functional keys  Extra keys Alphabetic keys contain alphabets from A-Z & a-z Numerical keys contain numbers 0-9 Symbols keys contain many symbols like !, @, #, $, % etc. Functional keys contain f1-f12, design for special purpose will discuss latter. Extra keys contain Esc, Alt, Ctrl, Backspace, Enter etc.  POINTING DEVICES A pointing device is an input device which is used to control a pointer on a screen. Pointer is a small symbol on a screen.  MOUSE “Mouse is an input device that fits under palm of hand and Controls the movement of the pointer” With the mouse, you can draw, select options from a menu, and modify or move text. You issue commands by pointing with the pointer and clicking a mouse button. In addition to minimizing typing errors, a mouse makes operating a microcomputer easier for beginning.  TYPES OF MOUSE There are three types of mouse Mechanical mouse Optical mouse Wireless mouse  TYPES OF MOUSE Mechanical mouse The mouse that contains a metal or rubber ball on its under side. When the ball is rolled in any direction, sensors inside the mouse detect this motion and move the on-screen mouse pointer in the same direction. Optical mouse An optical mouse uses a light-emitting (laser) to detect movement relative to the underlying surface. Wireless mouse Wireless mouse usually work via radio frequencies commonly referred to as RF. RF wireless mouse require two components to work properly a radio transmitter and a radio receiver.  JOY STICK A joystick is a pointing device often used for playing games. The joystick has a gearshift-like lever that is used to move the pointer on the screen. On most joysticks, a button on the top is used to select options. In industry and manufacturing, joysticks are used to control robots. Flight simulators and other training simulators also use joysticks.  TRACKBALL A trackball is like an upside-down mouse. Used similarly to the mouse, the trackball is frequently attached to or built into the keyboard. The main advantage of a trackball is that it requires less desk space than a mouse. (Some individuals in the computer industry believe that the mouse will soon be replaced by devices that do not require as much space to use.) The mouse is not practical for people using a laptop computer in a small space. Early alternatives, such as trackballs clipped to the side of the keyboard, have not proved satisfactory. The IBM ThinkPad replaces the trackball with a red plastic button, called a track point, located in the middle of the keyboard. You move the button with your thumbs. TRACKBALL  TOUCHPAD A touch pad is a device for pointing (controlling input positioning) on a computer display screen. It is an alternative to the mouse. Originally incorporated in laptop computers, touch pads are also being made for use with desktop computers. A touch pad works by sensing the user's finger movement and downward pressure.  TOUCHSCREEN A touch screen is a computer display screen that is also an input device. The screens are sensitive to pressure; a user interacts with the computer by touching pictures or words on the screen.  BIOMETRIC DEVICES A "biometric device" is any device that measures a biological function or characteristic. it identifies persons seeking access to a computing system by determining their physical characteristics through fingerprints, voice recognition, retina patterns, pictures, or other means.  VOICE RECOGNITION A system in which the computer recognizes human speech and transforms the recorded words into computer-readable digitized text or instruction. The conversion of spoken words into computer text. Speech is first digitized and then matched against a dictionary of coded waveforms. The matches are converted into text as if the words were typed on the keyboard.  THUMB IMPRESSION Biometrics can be defined as an automatic method for identification or identity verification of individuals using physiological or behavioral characteristics.  FACE RECOGNITION The ability to recognize people by their facial characteristics. The most advanced technology , which maps the characteristics of a person's face into a multidimensional face space. The computer can differentiate the same person with different appearances; for example, with or without glasses, change of hair style and seasonal skin color changes. It also uses in some secret agencies.  MIC / HEAD PHONE Both are input devices which are related to audio input. These device is used to enter sound in to the system for processing. It can be used in chatting, video conferencing, music or whenever we want to interact with the computer from voice input.  DIGITAL CAMERA A digital camera can be used to take pictures. It can be hooked up to a computer to transfer the pictures from the camera to the computer. it use light sensitive processing chip to capture pictures or images We can save these images where ever we want can be a CD, Computer disk, USB drive or can transfer from one computer to other computer or device.  DIGITAL SCANNER A scanner is used to copy pictures or other things and save them as files on the computer. A scanner is similar to a photocopier, except that instead of producing a paper copy of the document you place on it, you get an electronic copy which appears on your computer screen. This is very important input device use to convert a hardcopy file (printed paper) to a softcopy (image or display file).