Transcript Management Information Systems

Information Technology
Hardware
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Learning Objectives

When you finish this chapter, you will:
 Recognize
major components of an electronic
computer.
 Understand how the different components
work.
 Know the functions of peripheral equipment.
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Learning Objectives
 Be
able to classify computers into major
categories, and identify their strengths and
weaknesses.
 Be able to identify and evaluate key criteria
when deciding what computers to purchase.
 Know the controversy regarding the health
hazards of computers.
 Recognize how to evaluate hardware so that
you can harness it to improve managerial
processes.
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The Central Tool of Modern IS

Four Basic Functions of Computers
 Accept
data
 Process data
 Store data and instructions
 Output data
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The Central Tool of Modern IS
Figure 4.1 All computers have the same basic components.
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The Central Tool of Modern IS
Figure 4.2 Organizations have moved from using large mainframes to using
networked PCs.
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Computers Communicating: Bits And Bytes

Computer recognizes two states: on or off
 Each

on or off signal represents a bit (binary digit)
Encoding Schemes
 Representation

of symbols by unique strings of bits
Counting Bases
 Decimal
system is “base 10”
 Binary system is “base 2”

Used by computers
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A Peek Inside the Computer
Figure 4.6 A look inside a computer
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A Peek Inside the Computer

The Central Processing Unit (CPU)
 The
brain of the computer
 Microprocessor

Carries signals that execute all processing
 Two
Components:
Control unit
 Arithmetic logic unit (ALU)

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A Peek Inside the Computer
 Microprocessor
Silicon
chip embedded with transistors,
or semiconductors
Figure 4.7 Schematic of how circuits on a chip would be open and
closed to represent the letter D in EBCDIC (11000100)
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A Peek Inside the Computer
Figure 4.8 What happens inside the CPU in one machine cycle executing the
operation 7 + 5
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A Peek Inside the Computer

Machine Cycle
 CPU’s
execution of four functions:
Fetch
 Decode
 Execute
 Store

 Functions
measured in small fractions of a
second
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A Peek Inside the Computer

Memory
 CPU
Registers
 Internal Memory
Random access memory (RAM)
 Read-only memory (ROM)

 External

Memory
Magnetic disks, magnetic tapes, optical discs
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A Peek Inside the Computer
 Computer
Power
Clock
rate (measured in cycles
per second)
Amount of information the CPU
can process per second
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
Figure 4.10 Banks use magnetic-ink character recognition (MICR) to automate
their input procedures.
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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
Figure 4.11 In an RGB monitor, the electron gun creates many different
colors and hues from three primary colors: red, green, and blue.
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External Storage Media
 Important
Properties to Consider
Capacity
Speed
Cost
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External Storage Media
Magnetic Tapes
 Magnetic Disks
 Optical Discs (Compact Discs)
 Optical Tapes

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External Storage Media
 Business
Considerations of
Storage Media
Trade-offs
Modes
of Access
 Sequential
Access
 Direct Access
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External Storage Media
Figure 4.12 Characteristics of storage media for business consideration
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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

Minicomputers
 Often
used as the host computer in a network
of smaller computers
 Priced in the tens of thousands to a few
hundred thousand dollars
 Manufacturers: DEC (VAX), IBM (AS/400),
and Hewlett-Packard
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Classification of Computers
 Compatibility
 Software and peripheral devices from
one computer can be used with
another computer.
 In a networked environment,
computers need to communicate to
share databases and other computing
resources.
 In addition to power and cost,
compatibility is an extremely
important factor in purchasing
decisions.
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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
 Vendor reliability, warranty policy,
vendor support
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Considerations in the Purchase of Hardware
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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