Introduction to Computer Science PDF

Introduction to Computer Science By Dr/Safynaz AbdEl-Fattah Sayed Computer Science Beni-suef University What is a Computer?  What is a Computer? Example: summation of two numbers: 2, 5 Computer Characteristics Stages of computer development The Evolution of...

Introduction to Computer Science By Dr/Safynaz AbdEl-Fattah Sayed Computer Science Beni-suef University What is a Computer?  What is a Computer? Example: summation of two numbers: 2, 5 Computer Characteristics Stages of computer development The Evolution of the computers  Vacuum Tube Based. Magnetic Drums For Memory, Large In Size. Produce Enormous Heat. Lack In Versatility And Speed. Expensive. High Electricity Consumption. Examples: UNIVAC and ENIAC  Using transistors, it becomes smaller, faster, cheaper, energy- efficient and more reliable. Produce considerable heat. Used punched cards for input and printouts for output Magnetic core memory introduced. Assembly languages allowed programmers to specify instructions in words.  Based on Integrated Circuits (ICs). Transistors were made smaller in size and placed on silicon chips. Smaller size, faster, lower cost and more efficient. Keyboards and monitors were used. They were interfaced with an operating system which allowed to solve many problems at a time.  the size of the computer got reduced. Intel developed a CPU on a single chip (the microprocessor). This led to the development of microcomputers (Personal computers (PCs) and later workstations and laptops). They could be linked together to form networks, which eventually led to the development of the Internet.  FIFTH GENERATION (PRESENT & BEYOND): ARTIFICIAL INTELLIGENCE The speed is extremely high. The concept of Artificial intelligence (AI) has been introduced to allow the computer to take its own decisions. It is still in a developmental stage.  COMPUTERS CLASSIFICATION Six basic categories of computers: − Embedded computers Mobile devices Personal computers Midrange servers Mainframe computers Supercomputers  EMBEDDED COMPUTERS Designed to perform specific tasks or functions for that product. Cannot be used as general-purpose computers. Often embedded into: − Household appliances ‫األجهزة المنزلية‬ − Thermostats ‫منظمات الحرارة‬ − Sewing machines ‫ماكينات الخياطة‬ − Cars  MOBILE DEVICES A very small device with some type of built-in computing or Internet capability Typically based on cellular phones Examples: − Smart phones − Smart watches − Handheld gaming devices − Portable digital media players  MIDRANGE SERVERS Midrange server: A medium-sized computer used to host programs and data for a small network, Also called a minicomputer. a midrange server is usually located in an out-of-the-way place and can serve many users at one time. Users connect via a network with a desktop computer, portable computer, thin client, or a dumb terminal consisting of just a monitor and keyboard.  MAINFRAME COMPUTERS Mainframe computer: Powerful computer used by several large organizations to manage large amounts of centralized data. Standard choice for large organizations, hospitals, universities, large businesses, banks, government offices. Located in climate-controlled data centers and connected to the rest of the company computers via a network. Larger, more expensive, and more powerful than midrange servers. Usually operate 24 hours a day. Also called high-end servers or enterprise-class servers.  SUPER COMPUTERS Supercomputer: Fastest, most expensive, most powerful type of computers.  Generally run one program at a time, as fast as possible.  Commonly built by connecting hundreds of smaller computers, supercomputing cluster.  Used for space exploration, satellites, weather forecast, oil exploration, scientific research, complex Web sites, decision support systems, 3D applications, etc. Grid computing: Using the unused processing power of a large number of computers to work together on a single task.  PERSONAL COMPUTERS A computer system designed to be used by one person at a time, Also called a microcomputer. Are the least powerful, yet the most widely used and fastest- growing type of computer.  Personal Computer System Parts A Personal Computer System consists of the following: System unit: is the case that holds the computer’s main circuit boards, microprocessor, memory, power supply, and storage devices. Display device: consists of two parts:  Circuitry, called a graphics card, converts raw digital data into images that can be shown on a display device.  GPU (graphical processing unit): is a specific unit within graphics card that perform the actual image and graphics processing.  Display devices, called computer screens or monitors, present visual output, such as documents, photos, and videos. Keyboard: as the primary input device. Mouse: is an input device designed to manipulate on-screen graphical objects and controls.  Personal Computer System Parts Hard disk drive is the main storage device on a personal computer system that mounted inside the computer’s system unit. Optical drives: is a storage device that works with CDs, DVDs “digital versatile disc” or “digital videodisk”, or some combination of these storage media. Sound card and speakers: can output digital music, digitally recorded speech, and a variety of sound effects.  Sound card sends signals to speakers, which can be external devices or built into the system unit. Peripheral devices: A specified equipment that might be added to a computer system to enhance its functionality ex. Printer, Digital camera, Scanner, Joystick and Graphics tablet.  Data versus Information Data mean known facts that can be recorded and that have implicit meaning. Data and information are often used interchangeably; however, data are raw, unprocessed facts including text, numbers, images, and sounds. The result of processing data is Information. There are 3 types of data Structured data – Relational databases Semi-structured data – Documents, Email messages, … etc. Unstructured data – HTML pages, … etc. Digital data is stored electronically in files, common types of files are: Document Worksheet Database Presentation  Data Document Files Created by word processors to save documents such as reports, memos, term papers, and letters. Worksheet Files Created by electronic spreadsheets to analyze things like budgets and to predict sales  Data Database Files Typically created by database management programs to contain highly structured and organized data.  Presentation Files Created by presentation graphics programs to prepare presentation materials. COMPONENTS OF COMPUTERS