Transcript Chapter Three

Chapter 3
Computer
Hardware And
Software
Hardware vs. Software
 Hardware
• The physical equipment used to process
information
 Software
• Instructions that, with the help of people,
command the hardware to perform desired
tasks
Chapter 3
Slide 2
Computer Hardware Conceptual
Overview
Figure 3-1
Chapter 3
Slide 3
Computer Devices
 Processing hardware
• Controls the peripheral devices, as
directed by computer software
 Data bus
• Electrical connection managing the flow of
data between the processing hardware and
the rest of the computer
Chapter 3
Slide 4
Computer Devices
 Adaptors (controllers)
• Reside inside the computer and convert
commands and data from the data bus into
signals that peripheral devices can use
 Port
• A connection between the computer box
and a device outside the computer
Chapter 3
Slide 5
Computer Devices
 Input, output, and communications
devices
• Transfer data between a computer and its
users or other computers
 Storage devices
• Save data for later processing
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Slide 6
Uses of Input Hardware
 Active data entry
• A person uses an input device to enter
data into a computer
 Passive data entry
• The computer obtains information without
the active participation of a user
 Control
• A person uses an input device to control
the tasks or actions of the computer.
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Slide 7
Input Devices
 Keyboard
• Consists of a plastic or metal housing
containing keys that, when pressed, send a
signal to the computer
 Pointing devices
• Allow the user to control the movement of
a cursor (pointer) on the screen
Chapter 3
Slide 8
Input Devices
 Formatted Text Readers
• Read text formatted specifically for the
device in use
 Image Capture Devices
• Include scanners, digital still cameras, and
digital camcorders
Chapter 3
Slide 9
Input Devices
 Instrumentation devices
• Receive input through other devices, such
as machines and musical instruments, that
produce electrical output
 Sensors
• Devices that respond to the environment
with a signal that a computer can interpret
Chapter 3
Slide 10
Processing Hardware – The Execution
Cycle
Figure 3-5
Chapter 3
Slide 11
Measuring Processing Power
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Word length and bus width
Speed of arithmetic
Instruction speed
Instruction set
Pipelining
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Slide 12
Processing Hardware
 Parallel processing
• Uses two or more processors in a single
computer
 Specialized processors
• Processors, such as video accelerators,
voice processors, cryptographic
coprocessors, and DSPs, that perform
highly specialized tasks
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Slide 13
Processing Trends
 Moore’s Law
• A 1965 prediction by Gordon Moore, a cofounder of Intel, that the amount of
information storable in a square inch of
silicon would double about every 18
months
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Slide 14
Types of Storage Hardware
 Primary storage
• Electrical, resides on the bus, and is
directly accessible to the processor
 Secondary storage
• Storage that the processor cannot access
directly
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Slide 15
Types of Storage Hardware
 Volatile storage
• Requires electrical power to retain its data
 Non-volatile storage
• Retains its data in the absence of electrical
power
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Slide 16
Primary Storage Devices
 Cache memory
• Expensive super-fast primary storage
 RAM (random access memory)
• Volatile primary storage
 ROM (read-only memory)
• Non-volatile primary storage
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Slide 17
Secondary Storage Devices
 Fixed media
• Hard disk
• RAID
 Removable media
• Includes diskettes, cartridge disks,
magnetic tape, optical media, and flash
memory
Chapter 3
Slide 18
Other Storage Technologies
 Distributed Storage
• Storage Area Networks (SANs)
 Volumetric Storage
• Holographic
• MFD
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Slide 19
Hardware for Data Output
 Softcopy
• Output on an unmovable medium, such as
a computer screen.
 Hardcopy
• Output on a medium, such as paper, that
can be removed from the computer.
 Robotic
• Output into devices that physically move in
response to signals from a computer.
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Slide 20
Types of Software - Overview
Figure 3-12
Chapter 3
Slide 21
Types of Software
 Vertical application software
• Performs tasks common to a specific
industry, or a function within an industry
 Horizontal application software
• Addresses tasks that are common to users
in all or almost all industries
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Slide 22
Types of Software
 Systems Software
• Performs tasks to manage the devices and
resources of a computer and its network
 Systems-development software
• Used to create new software
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Slide 23
Vertical Software Issues
 Make vs. Buy
• Custom
• Customized
• Packaged (COTS)
 Integration
• Enterprise Resource Planning (ERP)
• Middleware
Chapter 3
Slide 24
Horizontal Software Types
 Office Automation
 Business Function Application
• Examples: Sales force management,
Human resources management, Inventory
management, Bookkeeping
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Slide 25
Systems Software
 Operating System Kernel
 Systems Utilities
 Network and Systems Management
Software
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Slide 26
Systems Development Software – Language
Differences
 Language Translation Method
• Interpreted
• Compiled
 Level of Abstraction
 Procedural vs. Non-Procedural
 Command/Data Oriented vs. Object
Oriented
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Slide 27
A Layered View of Software
 Client/Server model
• Divides a software application into at least
two separate but interdependent parts
called the client and the server
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Slide 28
Client/Server Models
 Two-tiered model
• Client responsible for user interface
• Server responsible for data storage and
management
• Result: Clients often need lots software
and storage -- fat clients
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Slide 29
Client/Server Models
 Three-tiered model
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Client: User interface
1st Tier Server: Business logic
2nd Tier Server: Data handling
Results in “thin clients”
 Multi-tiered models
• Divide application into many components,
each of which can call on the others to
perform services
Chapter 3
Slide 30
Peek Into The Future – Nanotechnology
 Nanotechnology
• Refers to building structures on a scale of
one-billionth of a meter, about five times
the diameter of a carbon atom
 Nanobots
• Nanometer-sized robots, able to perform
nano-assembly under the direction of a
computer; perhaps able to reproduce
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Slide 31
Peek Into The Future – Artificial Intelligence
 Rule-based systems
• One in which the computer makes
decisions based on logical rules
 Neural network
• Approach to artificial intelligence that
operates by mimicking the human brain
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Slide 32
Peek Into The Future – Artificial Intelligence
 Evolutionary algorithms
• Approach to artificial intelligence that
operates by observing the success or
failure of millions of different sets of rules
and approaches to solving a problem
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Slide 33
End of
Chapter 3
Computer
Hardware And
Software