Transcript Management Information Systems

Chapter 4
Information 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 Motorola’s 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
• CPU’s 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 Issues
Computers 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
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