Introduction to Computers

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Introduction to Computers

• Lecture 1.1
• Doug Hogan, 2003-04
• Penn State UniversityCMPSC 100 Computer
  Fundamentals and Applications

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Questions?

• Questions on syllabus?

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Office Hours

• In 338E IST drop-in
• Tuesday, 1-2 p.m.
• Wednesday, 1230-130 p.m.
• and by appointment
• You may find me there other times too
• Virtual on Instant Messenger (cmpsc100)
• whenever not away
• as requested
• look at profile of the account

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Attributes of Computers

• Speed
• Reliability
• Accuracy
• Storage
• Communication

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Applications

• Word processing
• Financial management
• Shopping
• Email
• Entertainment
• Many more

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Components of a Computer

• Central processing unit (CPU)
• Memory
• Input devices
• Output devices
• Storage devices

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Central Processing Unit (CPU)

• Basic job handle processing of instructions
• Whats an instruction?
• Two parts
• Control Unit (CU)
• Arithmetic and Logic Unit (ALU)

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The ALU

• Built up from digital logic gates
• AND
• OR
• NOT
• most primitive level

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Memory

• Holds programs that are currently running and the
  data being used by those programs.
• Two categories
• Read-only memory (ROM)
• can only read data
• Random-access memory (RAM)
• can read and write information

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Memory sizes

• base unit 1 bit binary digit, 0 or 1
• 8 bits 1 byte (B)
• 1000 bytes 1 kilobyte (KB)
• 1000 KB 1,000,000 B 1 megabyte (MB)
• 1000 MB 1,000,000,000 B 1 gigabyte (GB)

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Memory

• Related data organized into files

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Storage Devices

• Floppy disk
• 3.5 inches, 1.44 MB
• Hard disk
• typically sizes in GB
• Compact disc (CD)
• 650-700 MB
• CD-ROM read-only memory
• CD-R recordable
• CD-RW rewritable

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More Storage Devices

• Digital Versitale/Video Disc (DVD)
• 4.7 GB
• Zip disks and tape drives
• varies

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Input Devices

• mouse
• keyboard
• scanner
• camera
• microphone

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Output Devices

• monitor
• cathode ray tube (CRT)
• liquid crystal display (LCD)
• printer
• speakers

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Hardware vs. Software

• Hardware
• essentially, things you can touch
• input, output, storage devices
• Software
• essentially, what the computer knows
• data, 0s and 1s
• programs

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Software Overview

• System software
• Controls basic operations of computer
• The operating system
• manages memory, files, application software
• File management tasks deleting, etc.

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Software Overview

• Application software
• Not essential to system running
• Enables you to perform specific tasks
• Ex
• Office software
• Web browsers
• Media players
• Games

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Keyboard
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Keyboard Specifics

• CapsLock and Shift
• NumLock and numeric keypad
• Esc
• Editing and navigation keys
• insert, delete, home, end, page up, page down
• Function keys
• Ctrl, Alt
• PrintScreen

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Mouse operations buttons

• Click left button
• Click and drag
• Shift-click, Ctrl-click
• Double click
• Triple click
• Right click
• Scroll wheel