Download Computer Hardware Technologies

"Part I Understanding Information Systems Technology"
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COMPUTER
HARDWARE
TECHNOLOGIES
Information Systems Technology
Ross Malaga
Copyright © 2005 Prentice Hall, Inc.
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LEARNING GOALS
• Identify the major components of modern PCs.
• Explain how the components of a computer work together;
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Explain the role of the CPU and how it operates.
Explain input devices and how they operate.
Describe output devices and how they operate.
Describe multimedia and alternative I/O devices.
Explain the role of primary storage.
Describe secondary storage devices and how they operate.
• Describe various types of computers.
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Bead Bar Wants Computers
• Hardware choices should be driven by the specific
software the company needs to run
• Some of the requirements
– Meredith – Computers for managers
– Suzanne – Computer in each studio
– Mitch – Notebook (laptop) needed for cruise ships
– Julia – Keep the total hardware cost under $20,000
– Miriam – Marketing can save money by using
computers to develop their own materials
– Rachel – Mobile computing needed for traveling
purchasing rep
– Jim – Must be ergonomically designed
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The Core Computer Components
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Input device(s)
Output device(s)
Primary storage
Secondary storage
Central processing unit (CPU)
Busses
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The Historical Development
of Computers
• Babbage’s Analytical Engine – 1820s – 1870s
– Punched card program
– Lady Ada Byron, the first programmer
• Herman Hollerith
– Hollerith code
– Punched card tabulating machines – 1890 census
• ENIAC during WWII used vacuum tubes
• 1960s introduced transistor to replace tubes
• 1970s – introduction of the microprocessor
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The Rise of the PC
• 1974 – Altair 8800 – the first PC
• 1976 – Wosniak and Jobs – Apple I
• 1977 – Apple II
– Plastic case
– Keyboard
– Capable of color graphics
• 1981 – IBM PC (introduction of MS-DOS)
• 1984 – Apple Macintosh
– Graphical User interface (GUI) pioneered a
Xerox PARC
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Input Devices
• Human input devices
– Allow person to send data to the computer
– Keyboard
– Mouse (and other pointing devices)
• Machine-readable input devices
– Send data directly to computer without human
involvement
– No human involvement means no human error
– Usually faster than human input
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Keyboard as Input Device
• Easy way to enter text, numbers, and simple
commands
• Follows the layout of the typewriter
• QWERTY keyboard leads to RSIs
– Repetitive Stress Injuries
– Requires increased attention to ergonomics of
the work environment
• Posture
• Lighting
• Working
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Machine-readable Input Devices
• Bar code scanners
– Uses light to read series of coded stripes
– Universal Product Code (UPC) – Adams.com
– Package tracking at UPS
• Optical Character Recognition (OCR)
– Software that works with scanner
– Translates scanned digital image to character that user
can recognize and manipulate
• Magnetic Ink Character Recognition (MICR)
– Character recognition technology used by banks to allow
rapid routing of checks between banks
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Output Devices
• Monitors
– Cathode ray tube (CRTs)
– Liquid crystal displays (LCDs)
– Quality of display
• Resolution
• Dot pitch
• Touch screens
– Input and output via display device
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Printers
• Speed and resolution
– Pages per minute
– Dots per inch
• Number of ink dots to fill a square inch
• Higher DPI the greater the page clarity
• Impact
– Create image by striking paper and ribbon
– Dot-matrix
• Non-impact
– Create image by spraying or rolling ink on the
page
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Non-impact Printers
• Ink-jet technology printers
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Spray ink on the paper
Small
Quiet
Color is readily and cheaply available
• Laser printers
– Laser heats drum which rolls ink (toner) on
paper
– Can be faster than ink-jet
– Color more expensive than ink-jet
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Multimedia I/O Devices
• Music, images, and video
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Convert content to digital form
How MP3s work at HowStuffWorks.com
Digital cameras ; digital camera phones
Digital Video DVD recorders – Sony Handicam
Game controllers
Virtual reality (VR)
Voice recognition
Text-to-speech
Brain wave input
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Primary Storage
• Digital data stored in bits – BInary digiTs
• Combination of 8 bits is called a byte
• Different combinations of bits represent
different symbols
– ACSII
– EBCDIC
• All data and programs are represented in bits
– Video
– Pictures
– Text
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Primary Storage (Continued)
• The main memory of the computer
• Stored on semiconductor chips
– RAM – random access memory
• Volatile
• Cache memory
– Internal – ultra high speed and VERY expensive
– External – very high speed and less expensive than internal cache
– ROM – read only memory
• Non-volatile
• Primary storage holds all programs that are running
and the data those programs use
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Secondary Storage
• Nonvolatile storage of digital data
• Magnetic or optical
• Magnetic media
– Sequential access (tape) or direct access (HDD)
– Hard disk drives
• Metal disk with metallic coating
• Disk spins at speeds of up to 7000 rpm
• RAID – redundant array of inexpensive disks
– Floppy disks
– Magnetic tape
– Zip disks and other magnetic storage alternatives
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Hard Disk Drives and Direct Access
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Optical Secondary Storage
• Compact disks (CDs)
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600 MB capacity
CD-ROM
CD-R
CD-RW
• Digital versatile disks (DVDs)
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2 – 17 GD capacity
DVD
DVD+/-R
DVD+/-RW
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The Central Processing Unit
• Two main components
– Arithmetic and logic unit (ALU)
– Control unit (CU)
– Registers are used as scrap paper – intermediate
results
• Speed measured in hertz
– Megahertz – millions of instructions per second
– Gigahertz – billions of instructions per second
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Moore’s Law on Processor Speed
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Computer Program Instruction
Execution
• Connect all the pieces together
– Bus – electrical pathway
– All digital data moves from component to component on
the bus
• Executing an instruction
– Control unit fetches next instruction from primary storage
and stores it onboard the CPU
– The control unit decodes the instruction
– The ALU executes the instruction possibly accessing other
data in primary storage
• Cycle is repeated millions of times per second
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Types of Computers
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Supercomputers
Mainframes
Minicomputers
Workstations
Desktop computers
Notebook computers (laptops)
Handheld computers (PDAs)
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Bead Bar Consultant
• How Computer Hardware Issues Affect the Bead Bar
– Meredith – Needs to understand the technology and terms
– Suzanne – Computers in studios to improve studio operations
– Leda – Use computers to improve franchise record keeping
and marketing
– Mitch –Portable computer to allow working while traveling
– Julia – Concerned about costs, including ROI
– Miriam – Use multimedia to develop marketing materials
– Rachel – Use bar codes and handhelds to reduce errors and
streamline operations
– Jim – Upgrading skills of employees and finding new
employees to hire with the proper computer skills
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Learning Goals Summary
In this chapter you have learned:
 The major components of modern PCs
 How the components of a computer work together
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The role of the CPU and its operation
Input devices and how they operate
Output devices and how they operate
Multimedia and alternative I/O devices
The role of primary storage
Secondary storage devices and operation
The various types of computers
Copyright © 2005 Prentice Hall, Inc.
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