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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.
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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
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• 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
Where Computers Are Used?
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Computer SystemMemory
Central processing unit(CPU)
Input
Disk Auxiliary Storage Disk
Output
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Front of the Computer
CD-ROM Drive
Floppy Drive
Keyboard
Monitor
Mouse
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Inside the Computer
• CD-ROM• CPU• Expansion Slots• Floppy drive• Hard disk• Memory chip• Motherboard• Power Supply
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Back of the Computer
• Cooling Fan• Power Supply• Keyboard Connector
• Mouse Connector• Parallel Printer Port • Video Connector
• Mouse Connector• Parallel Printer Port • Video Connector
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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
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• CD-ROM• Tape Backup• Hard disk • Zip Drive• Floppy Disks• DVD
Auxiliary Storage
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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
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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
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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
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Input and Output Units
• Keyboard
• Mouse
• Trackball
• Scanner
• Joystick
• Pen
• Monitor
• Printers– Ink Jet
• B/W or color• Smears
– Lasers• Highest quality output
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Modems/Network Cards
• Fax/Modem– 56Kbps/V.90
• Cable Modem– Uses TV cable
• DSL Modem– Voice and Data on
same line
• Network Cards
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Additional Devices
• Multimedia– CD ROM or DVD– Sound Card– Speakers
• Other Devices– Scanner– Camera
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Software• System
– MS-DOS– Mac OS– Unix– Linux– Windows
• Application– Word Processing– Spreadsheets– Presentation– Games– Antivirus– Others
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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
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Introduction to Windows
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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
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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
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The Windows Desktop
Start Button
Taskbar (multitasking)
My Computer
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Anatomy of a Window
• Title bar with Min, Max or Restore, and Close buttons• Menu bar, Toolbar, and Address bar• Status bar and Scroll bars
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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
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Pull-down Menus
• Pull-down menu• Dimmed command• Ellipsis• Check• Bullet• Arrowhead• Submenu
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Dialog Boxes
• Tabbed dialog box• Option buttons• Check box• Text box• Spin button• Command buttons
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Dialog Boxes continued
• Command buttons• Open List Box• Scroll bar• List box• Tabbed dialog box• Help button ?• Cancel button• OK button
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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
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Formatting a Floppy
• Disk capacity– 720Kb– 1.44Mb
• Types of formatting– Quick (erase)– Full
• Label
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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
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Windows Explorer• Folder
– Expanded– Collapsed
• Files– Program file– Data file
• File names– Name– Extension
(type)
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Moving and Copying Files
• 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
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The Help Command
• Accessed from the Start button
• Tabs– Contents tab– Index tab– Search tab– Favorites tab
• Web help
