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What is Computer?. A computer is a machine that can be programmed to process data (input) into useful information (output). A computer system comprises four main aspects of data handling: input, processing, output and storage. The Nature of Computers.
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What is Computer? A computer is a machine that can be programmed to process data (input) into useful information (output). A computer system comprises four main aspects of data handling: input, processing, output and storage.
The Nature of Computers • Speed – essential to our fast-paced society • Reliability – extremely reliable / human errors • Storage Capability – tremendous amounts of data • Productivity – doing better and faster jobs • Decision Making – need to take into account financial, geographical and logistical factors • Cost Reduction – holds down teh costs of labor, energy and paperwork
Where Computers Are Used? • Education • Graphics • Retailing • Energy – to locate oil, natural gas, coal • Law Enforcement – fingerprint, DNA • Transportation – car technologies, air traffic • Money • Agriculture • Government • Home • Healt and Medicine • Robotics • The Human Connection • The Sciences • Connectivity • Training
Memory Input Central processing unit (CPU) Output Disk Disk Auxiliary Storage Computer System
Front of the Computer CD-ROM Drive Floppy Drive Keyboard Monitor Mouse
CD-ROM CPU Expansion Slots Floppy drive Hard disk Memory chip Motherboard Power Supply Inside the Computer
Cooling Fan Power Supply Keyboard Connector Mouse Connector Parallel Printer Port Video Connector Back of the Computer • Mouse Connector • Parallel Printer Port • Video Connector
Microprocessor • Brain of the computer • Current chips for PC • Intel (Celeron, Pentium III, Pentium IV and Centrino, Core 2 Duo) • AMD (K-6, Athlon, Sempron) • Which do I buy? • Core 2 Duo or Sempron for graphic intensive programs • K-6 or Celeron for business and Internet browsing
CD-ROM Tape Backup Hard disk Zip Drive Floppy Disks DVD Auxiliary Storage
Auxiliary Storage (Permanent) • Floppy Disk • Most common is 1.44Mb • LS-120 disk is 120Mb • High Capacity Removable Storage • Zip disks (100 or 250Mb) • Jaz Disks (1 or 2Gb) • Hard (Fixed) Disk • Most common are 80 Gb – 1 Tb
Auxiliary Storage (Continued) • CD-ROM (800Mb) • Recordable devices also available • DVD drives (4.7Gb-17Gb) • ROM and RAM • Higher capacity than CD • Tape Units • Used for large, unattended back-ups
Internal Memory (RAM) • Temporary (erased when power turned off) • Measured in bytes • 1 Byte = 1 character (8 bits) • 1 Kilobyte = 210 (~1,000 bytes) • 1 Megabyte = 220 (~1,000,000 bytes) • 1 Gigabyte = 230 (~1,000,000,000 bytes) • Need 1024Mb – 4096 Mb of RAM • Want to keep multiple programs & data files in memory • Graphic intensive programs demand a lot of memory
Keyboard Mouse Trackball Scanner Joystick Pen Monitor Printers Ink Jet B/W or color Smears Lasers Highest quality output Input and Output Units
Modems/Network Cards • Fax/Modem • 56Kbps/V.90 • Cable Modem • Uses TV cable • DSL Modem • Voice and Data on same line • Network Cards
Additional Devices • Multimedia • CD ROM or DVD • Sound Card • Speakers • Other Devices • Scanner • Camera
Software • System • MS-DOS • Mac OS • Unix • Linux • Windows • Application • Word Processing • Spreadsheets • Presentation • Games • Antivirus • Others
Classification of Computers • Personal Computers • Notebook Computers – lightweight and portable • Handheld Computers – personal digital assistant (PDA) • Midrange Computers – design to serve the needs of medium sized organizations • Mainframes – processing data at very high speed • Supercomputers – process trillions of instructions per second
Evolution of Windows • Windows 3.1 • First widely used successful version of Windows • Replaced MS-DOS • Windows 95 • Introduced Start button, taskbar for multitasking, and My Computer for easier file management • Windows NT • Intended for business computing • Increased reliability and security
Evolution of Windows (Continued) • Windows 98 • Active desktop displays Web content • Enables Web conventions on the desktop • Windows 2000 • Security of NT with Windows 98 Interface • Windows 2000 Professional and Windows 2000 Server • Windows Me (Millennium Edition) • Successor to Windows 98 for home computing
My Computer Start Button Taskbar (multitasking) The Windows Desktop
Title bar with Min, Max or Restore, and Close buttons Menu bar, Toolbar, and Address bar Status bar and Scroll bars Anatomy of a Window
The Devices on a System • Drive A is always a floppy disk • Drive B is a second floppy disk (obsolete) • Drive C is always a fixed disk • Drives D, E, are variable • CD ROM • Zip drive or removable media • Network drives
Pull-down Menus • Pull-down menu • Dimmed command • Ellipsis • Check • Bullet • Arrowhead • Submenu
Dialog Boxes • Tabbed dialog box • Option buttons • Check box • Text box • Spin button • Command buttons
Dialog Boxes continued • Command buttons • Open List Box • Scroll bar • List box • Tabbed dialog box • Help button ? • Cancel button • OK button
Moving and Sizing a Window • To Move a Window • Click and drag the title bar • To Size a Window • Click and drag a corner to change the length and width in proportion with one another • Click and drag a border to change just the length or the width
Formatting a Floppy • Disk capacity • 720Kb • 1.44Mb • Types of formatting • Quick (erase) • Full • Label
File Management • My Computer • Simpler and less sophisticated • Can result in multiple open windows at one time • Windows Explorer • Hierarchical view on left • Contents of the selected folder on the right • Multiple views available for both • Small icons, Large icons, List, and Details view
Folder Expanded Collapsed Files Program file Data file File names Name Extension (type) Windows Explorer
Moving Files Click and drag to a different folder on the same drive Cut and Paste Shortcut Menu Copying Files Click and drag from one drive to another Copy and Paste Shortcut Menu Moving and Copying Files
Accessed from the Start button Tabs Contents tab Index tab Search tab Favorites tab Web help The Help Command