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Computer and Data Processing. MGM2191 Semester 2 (2009/2010) Distance Learning (PJJ). Computer and Data Processing. Chapter 1- Introduction to Computers Chapter 2- The Internet and the WWW Chapter 3- Application Software Chapter 4- The Components of System Unit
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Computer and Data Processing MGM2191 Semester 2 (2009/2010) Distance Learning (PJJ)
Computer and Data Processing Chapter 1- Introduction to Computers Chapter 2- The Internet and the WWW Chapter 3- Application Software Chapter 4- The Components of System Unit Chapter 5- Input Chapter 6- Output
A World of Computers Next • What is computer literacy? • Knowledge and understanding of computers and their uses • Computers are everywhere
What Is a Computer? Processes data into information Data that is organized, meaningful, and useful Acceptsdata Raw facts, figures, and symbols Produces and stores results Next • How is a computer defined? • Electronic device operating under the control of instructions stored in its own memory
What Is a Computer? Next • What is the information processing cycle? • Input • Process • Output • Storage • Communication
What Is Input? Next • What isinput? • Data or instructions entered into memory of computer • Input device is any hardware component that allows users to enter data and instructions
What is Output? Next • What isoutput? • Data that has been processed into a useful form • Output device is any hardware component that can convey information to one or more people
Categories of Output Next • What are the four categories of output? • Text, graphics, audio and video What is adisplay device? • Output device that visually conveys text, graphics, and video information • **Information on display device sometimes called soft copy
The Components of a Computer Next • What is the system unit? • Case that containsthe electronic components of the computer that are used to process data • Sometimes called the chasis
The System Unit Next • What are common components inside the system unit? • Processor • Memory • Adaptercards • Sound card • Video card • Drive bays • Powersupply
The System Unit Click to view Web Link,click Chapter 4, Click Web Linkfrom left navigation, then click Motherboards below Chapter Next • What is themotherboard? • Main circuit board of the system unit • Contains expansion slots, processor chips, and memory slots • Also calledsystem board
The Components of a Computer Next • What are two main components on the motherboard? Processor Also called a Central Processing Unit (CPU) The electronic component that interprets and carries out the basic instructions that operate the computer Memory Consists of electronic components that store instructions waiting to be executed and data needed by those instructions
Processor Processor Control Unit Arithmetic Logic Unit (ALU) InstructionsDataInformation InstructionsDataInformation Next • What is thecentral processing unit (CPU)? • Interprets and carries out basic instructions that operate a computer Control Unit Arithmetic Logic Unit (ALU) • Control unit directs and coordinates operations in computer • Arithmetic logic unit (ALU) performs arithmetic, comparison, and logical operations Memory InputDevices OutputDevices Data Information • Also called theprocessor StorageDevices
Processor Memory Processor ALU Control Unit Next • What is amachine cycle? • Four operations of the CPU comprise a machine cycle Step 1. FetchObtain program instruction or data item from memory Step 2. DecodeTranslate instruction into commands Step 4. StoreWrite result to memory Step 3. ExecuteCarry out command
Data Representation Next • How do computers represent data? • Most computers aredigital • Recognize only two discrete states: on or off • Use a binary system to recognize two states • Use Number system with two unique digits: 0 and 1, called bits (short for binary digits)
Data Representation Next • What is abyte? • Eight bits grouped together as a unit • Provides enough different combinations of 0s and 1s to represent 256 individual characters • Numbers • Uppercase and lowercase letters • Punctuation marks • Other
Data Representation ASCII Symbol EBCDIC 00110000 0 11110000 00110001 1 11110001 00110010 2 11110010 00110011 3 11110011 Next • What are three popular coding systems to represent data? • ASCII—AmericanStandardCodeforInformationInterchange • EBCDIC—ExtendedBinaryCoded DecimalInterchangeCode • Unicode—coding scheme capable of representing allworld’s languages p. 195 Fig. 4-13
Data Representation Step 1.The user presses the capital letter T (SHIFT+T key) on the keyboard. Step 2.An electronic signal for the capital letter T is sent to the system unit. T Step 4.After processing, the binary code for the capital letter T is converted to an image, and displayed on the output device. Next • How is a letter converted to binary form and back? Step 3.The system unit converts the scan code for the capital letter T to its ASCII binary code (01010100) and stores it in memory for processing.
Memory Next • What ismemory? • Electronic components that store instructions, data, and results • Consists of one or more chips on motherboard orother circuit board • Each byte stored in unique location called anaddress, similar to seats in a concert hall
Memory Term Abbreviation Approximate Size Kilobyte KB or K 1 thousand bytes Megabyte MB 1 million bytes Gigabyte GB 1 billion bytes Terabyte TB 1 trillion bytes Next • How is memory measured? • By number of bytes available for storage
Memory Click to view Web Link,click Chapter 4, Click Web Linkfrom left navigation, then click RAM below Chapter Next • What israndom access memory (RAM)? Memory chips that can be read from and written to by processor Also called main memory or primary storage Most RAM is volatile, it is lost when computer’s power is turned off The more RAM a computer has, the faster it responds
Memory RAM RAM Next • How do program instructions transfer in and out of RAM? Step 1.When you start the computer, certain operating system files are loaded into RAM from the hard disk. The operating system displays the user interface on the screen. Operating system interface Operating system instructions Step 2.When you start a Web browser, the program’s instructions are loaded into RAM from the hard disk. The Web browser window is displayed on the screen. Web browser instructions Web browser window Step 3.When you start a paint program, the program’s instructions are loaded into RAM from the hard disk. The paint program, along with the Web Browser and certain operating system instructions are in RAM. The paint program window is displayed on the screen. Paint program instructions Paint program window Step 4.When you quit a program, such as the Web browser, its program instructions are removed from RAM. The Web browser is no longer displayed on the screen. Web browser program instructions are removed from RAM Web browser window is no longer displayed on desktop
The Components of a Computer Next • What is storage? • Holds data, instructions, and information for future use Storage media • Physical material on which data, instructions, and information are stored Storage device • Records and retrieves items to and from storage media
The Components of a Computer Next • What is a USB flash drive? • Portable storage device • Small and lightweight enough to be transported on a keychain or in a pocket • The average USB flash drivecan hold about 500 millioncharacters
The Components of a Computer Next • What is a hard disk? • Provides greater storage capacity than a USB flash drive • Most are housed inside the system unit
The Components of a Computer Next • What is a compact disc? • Flat, round, portable metal disc • CD-ROM • DVD-ROM p. 9 Fig. 1-5
The Components of a Computer Click to view Web Link,click Chapter 1, Click Web Linkfrom left navigation, then click Communications Devices below Chapter 1 Next • What is a communications device? Hardware component that enables a computer to send and receive data, instructions, and information Occurs over cables, telephonelines, cellular radio networks,satellites, and other transmission media
Advantages and Disadvantages of Using Computers Reliability Speed Consistency Storage Communications Next • What are the advantages of using computers?
Advantages and Disadvantages of Using Computers Next • What are the disadvantages of using computers? Violation ofPrivacy Public Safety Impact onLabor Force Health Risks Impact onEnvironment
Networks and the Internet Next • What is a network? • Collection of computers and devices connected together Used to share Resources Hardware devices Software programs Saves time and money Data Information
Networks and the Internet Next • What is a server? • A server controls access to resources on a network • Clients, or workstations, request resources from the server
Networks and the Internet Click to view Web Link,click Chapter 1, Click Web Linkfrom left navigation, then click Internetbelow Chapter 1 Next • What is the Internet? • Worldwide collection of networks that connects millions of businesses, government agencies, educational institutions, and individuals
Networks and the Internet Next Why do users access the Internet? • Communications Information Shopping Banking and Investing Classes Entertainment 7.Download Music 8. Share Information
Computer Software Next • What is software? Consists of a seriesof instructions thattells the computerwhat to do and how to do it Also called aprogram
Computer Software Next • What is a graphical user interface (GUI)? • Allows you to interact with the software using text, graphics, and visual images such as icons • Controls how you enter data and instructions and how the screen displays information
Computer Software Next • What issystem software? • Programs that control or maintain the operations of the computer and its devices Operating System (OS)is a set of programs that coordinates all activities among computer hardware devices Utility Programsallow the user to perform maintenance-type tasks usually related to managing a computer, its devices or its programs
Application Software Next • What is system software? • Serves as the interface between the user, the application software, and the computer’s hardware
Computer Software Click to view Web Link,click Chapter 1, Click Web Linkfrom left navigation, then click Application Software below Chapter 1 Next • What isapplication software? • Programs designed to make users more productive Word Processing Spreadsheet Database Presentation Graphics
Computer Software JavaScript Web application Next • What is aprogrammer? • Someone who developsapplication or system software • Programmer writesthe instructions todirect the computer toprocess data intoinformation
Categories of Computers Next What are the categories of computers? Personal Computers(desktop) Mobile Computers andMobile Devices Game Consoles Servers Mainframes Supercomputers Embedded Computers
Personal Computers • Apple Macintosh usually uses the Macintosh operating system (Mac OS X) • PC and compatibles use the Windows operating system Click to view Web Link,click Chapter 1, Click Web Link from left navigation, then click Personal Computers below Chapter 1 Next • What are the two most popular styles of personal computers?
Personal Computers Next • What is adesktop computer? • Designed so all of the components fit entirely on or under a desk or table
Mobile Computers and Mobile Devices Next • What is anotebook computer? • Portable, small enough to fit on your lap • Also called a laptop computer • Usually more expensive than a desktop computer with equal capabilities
Mobile Computers and Mobile Devices Next • What is aTablet PC? • Resembles a letter-sized slate • Allows you to write on the screen using a digital pen • Especially useful for taking notes
Mobile Computers and Mobile Devices Next • What are mobile devices? Small enough tocarry in a pocket Internet-enabledtelephone is a“smart phone”
Mobile Computers and Mobile Devices Small enough to fit in one hand Used by mobile employees such as meter readers and delivery people Next • What is ahandheld computer?
Mobile Computers and Mobile Devices Next • What is apersonal digital assistant (PDA)? • Provides personal organizer functions • Calendar • Appointment book • Address book • Calculator • Notepad
Mobile Computers and Mobile Devices A smart phone isan Internet-enabledtelephone that usuallyprovides PDA capabilities Click to view Web Link,click Chapter 1, Click Web Link from left navigation, then click Smart Phones below Chapter 1 Next • What aresmart phones?
Embedded Computers Next • What is an embedded computer? • A special-purpose computer that functions as a component in a larger product
Elements of an Information System Next • What are information system elements? • Hardware • Software • Data • People • Procedures