Chapter 4 Information Technology in Business: Hardware

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Chapter 4Information Technology in Business
Hardware
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Learning Objectives

• List major components of a computer and explain
  their functions
• Explain how computers communicate
• Classify computers into major categories, and
  identify their strengths and weaknesses
• Describe how computers have affected the
  development of business

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Learning Objectives (Cont.)

• Define the most commonly used hardware
  terminology
• Identify and evaluate key criteria when deciding
  what computers or related devices to purchase
• Explain the controversy regarding the health
  hazards of computers
• Evaluate hardware so that you can harness it to
  improve managerial processes

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The Central Tool of Modern Information Systems

• Computers are at the core of every modern
  information system
• Hardware the physical components of the computer
• Software the set of instructions that direct the
  hardware to perform particular tasks

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Hardware components

• Input devices receive signals from outside the
  computer and transfer them into the computer
• Computer keyboard and mouse
• Some input devices accept voice, image, or other
  signals

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Central processing unit (CPU)

• Most important part of any computer
• Accepts instructions and data
• Decodes and executes instructions
• Stores results (output) in memory for later
  display

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Internal Memory or Main Memory

• Stores data and instructions just before and
  immediately after the CPU processes them
• Includes programs currently running on a machine
• Intermediate results of arithmetic operations
• Intermediate versions of documents being word
  processed
• Data that represent pictures displayed on a
  computer screen
• Sounds played by the speakers

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Internal Memory or Main Memory (Cont.)

• Two types of memory
• RAM (random access memory)
• ROM (read-only memory)
• The amount of memory and the speed at which it
  can be retrieved are two properties that
  determine the power of a computer

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External Memory

• Different types of media
• Magnetic disks, magnetic tapes, and optical discs
• Stores same types of data and information as
  internal memory does
• Allows for permanent storage and portability

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Output devices

• Computer monitors and printers
• Deliver information from the computer to a person
• Audio output devices
• Specialized output devices Braille writers

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The Central Tool of Modern Information Systems
(Cont.)

• Devices for both output and input
• Printers that read memory cards to print digital
  images
• Most I/O devices are peripheral devices
• Most processing and storage devices are internal
• CPU and primary memory reside on the motherboard

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The Central Tool of Modern Information Systems
(Cont.)
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How Computers Communicate Bits And Bytes

• Computer recognizes two states
• On or off
• Each on or off signal represents a bit (binary
  digit)

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Encoding Schemes

• Representation of symbols by unique strings of
  bits
• ASCII (American Standard Code for Information
  Interchange) originally with seven bits in a byte
• ASCII-8
• Newer version
• Consists of eight bits per byte

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Encoding Schemes (Cont.)
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Encoding Schemes (Cont.)

• EBCDIC, Developed by IBM with eight bits per byte
• Limitations in ASCII and EBCDIC to 256 different
  characters
• Unicode, 16 bits per byte, allows for many more
  characters

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Understanding Computer Processing

• Counting Bases
• Decimal system is base 10
• Binary system is base 2
• Similar methods for calculations as humans
• Store all quantities and perform calculations in
  binary form
• Display numbers after translating to decimal
  presentation

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Classification of Computers

• Supercomputers
• The largest, most powerful, and most expensive
• Used by universities, research institutions, and
  large corporations
• Mainframe Computers
• Less powerful and less expensive than
  supercomputers
• Used by businesses with large amounts of data
  that need to be stored in a central computer

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Classification of Computers (Cont.)

• Midrange Computers
• Often used as the host computer in a network of
  smaller computers
• Priced in the several thousands to a few hundred
  thousand dollars
• Manufacturers DEC (VAX), IBM (AS/400), and
  Hewlett-Packard

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Classification of Computers (Cont.)

• Microcomputers
• Networks of microcomputers are replacing
  mainframes
• Sometimes called workstations
• Used for CAD, CAE, complex simulations and
  scientific applications

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Classification of Computers (Cont.)

• Microcomputers (cont.)
• The microprocessor chip
• Traditionally manufactured by Intel
• AMC and Cyrix are other manufacturers
• Macintosh are built around Motorolas PowerPC
  chips
• Sun develops its own microprocessors and
  computers

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Classification of Computers (Cont.)

• Computers on the Go Notebook, Handheld, and
  Tablet computers
• Computers used outside the office
• 3x the desktop pc price
• Tablet pc is the newest option available

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Classification of Computers (Cont.)

• Internet Appliances
• Handheld computers and other electronic devices
  manufactured with the capability to link to the
  Internet
• Can be wireless
• Considerations must be made for invasion of
  privacy concerns
• More devices being outfitted for Internet access
  all the time

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Business Evolves with Computing

• Mainframe to PC Networking Businesses
• With increased power of the PC, managers devise
  their own IS
• Businesses shifting from mainframe model to the
  client/server model
• One PC functions as the server
• Connects to other PCs, the clients

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Trends in Computing

• Increasing power, decreasing cost
• Electronic computing began with early counting
  machines
• Electrical signals an important leap in
  technology
• 1942 first electronic computer at Iowa State

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Trends in Computing (Cont.)

• Used by the US Government
• IBM machines used in 50s and 60s for business
  calculations, record keeping and more
• Today, nearly every new electronic device has a
  computer

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Business Evolves with Computing
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Business Evolves with Computing
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A Peek Inside the Computer
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A Peek Inside the Computer (Cont.)

• The Central Processing Unit (CPU)
• The brain of the computer
• Has two components that store and process data
• Control unit
• Arithmetic logic unit (ALU)
• Silicon chip with multiple circuits

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A Peek Inside the Computer (Cont.)
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A Peek Inside the Computer (Cont.)

• The Central Processing Unit (CPU) (cont.)
• Microprocessor
• Carries signals that execute all processing
• More transistors on the chip, the greater the
  power of the processor
• Silicon chip embedded with transistors, or
  semiconductors

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Machine Cycle

• CPUs execution of four functions is one cycle
• Fetch, Decode, Execute, Store
• Rate of repetitive cycles is Clock Rate
• One cycle per second is one hertz
• Computer frequencies are measured in megahertz
  (MHz-millions of hertz) or gigahertz
  (GHz-billions of hertz)
• System clock synchronizes all these tasks

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A Peek Inside the Computer (Cont.)
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A Peek Inside the Computer (Cont.)

• The Word maximum number of bits fetched in one
  cycle
• The Arithmetic Logic Units Operations where all
  arithmetic and logical operations take place
• Reduced Instruction Set Computing fewer
  instructions resulting in faster computing

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A Peek Inside the Computer (Cont.)

• Memory
• Registers
• Primary Memory
• Random access memory (RAM)
• Cache Memory
• Read-only memory (ROM)
• Volatile v. Nonvolatile

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Computer Power

• Clock rate
• Bus amount of information the CPU can process
  per second
• Throughput speed determined only by combination
  of both factors

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Input Devices

• Keyboard
• Mouse, Trackball, and Track Pad
• Touch Screen
• Source Data Input Devices
• Imaging
• Speech Recognition

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Input Devices (Cont.)
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Output Devices

• Soft-Copy Output Devices
• Cathode-Ray Tube (CRT) Monitor
• Flat-Panel Monitor
• Speech Output
• Hardcopy Output Devices
• Nonimpact Printers (most common)
• Impact Printers

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Output Devices (Cont.)
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External Storage Media

• Important Properties to Consider
• Capacity, Access Speed, Access Mode, Cost
• Mode of Access
• Sequential v. Direct Access
• Magnetic tapes

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External Storage Media (Cont.)

• Magnetic Disks
• Optical Disks
• Optical Tapes
• Flash Memory and Thumb Drives

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Business Considerations of Storage Media

• Trade-offs
• Modes of Access
• Sequential Access Tapes
• Direct Access Disks

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External Storage Media (Cont.)
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External Storage Media (Cont.)
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Considerations in Purchasing Hardware

• What should you consider when buying hardware?
• Power -- speed, size of memory, storage capacity
• Expansion and upgrade capability
• Ports for external devices like printers, hard
  disks, communication devices
• Ergonomics Keyboard, Monitor

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Considerations in Purchasing Hardware (Cont.)

• What should you consider when buying hardware
  (cont.)?
• Footprint
• Vendor reliability, warranty policy, vendor
  support
• Compatibility
• Cost

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Considerations in Purchasing Hardware (Cont.)

• Factor What to Look For
• Power Greater frequency and word size, larger
• Expandability Greater number of board slots for
  additional RAM
• Ports Greater number of ports for printer,
  external hard disk, communication devices and
  other peripherals
• Ergonomics Greater comfort and safety
• Compatibility Comparability with many other
  computers and peripheral devices, as swell as
  software packages
• Footprint Smaller area
• Support Availability of telephone and on-line
  support for troubleshooting
• Warranty Longer warranty period
• Cost Lower cost

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Considerations in Purchasing Hardware (Cont.)

• Factor What to Look For
• Power Greater frequency and word size, larger
• Expandability Greater number of board slots for
  additional RAM
• Ports Greater number of ports for printer,
  external hard disk, communication devices and
  other peripherals
• Ergonomics Greater comfort and safety
• Compatibility Comparability with many other
  computers and peripheral devices, as swell as
  software packages
• Footprint Smaller area
• Support Availability of telephone and on-line
  support for troubleshooting
• Warranty Longer warranty period
• Cost Lower cost

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Ethical and Societal IssuesComputers May Be
Hazardous to Your Health

• Physical and Emotional Stress
• General physical and emotional stress
• Muscular-skeletal problems
• Repetitive Stress Injuries (RSI)
• Vision problems

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Summary

• Computer components and their functions
• Computer communication
• Categories of computers have different strengths
  and weaknesses
• Understand commonly used hardware terminology
• Identify and evaluate key criteria for purchasing
  decisions