chapter 3 computer hardware and software. chapter 3slide 2 hardware vs. software hardware the...
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Chapter 3Chapter 3
Computer Hardware And Software
Chapter 3 Slide 2
Hardware vs. SoftwareHardware 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 3
Computer Hardware Conceptual OverviewComputer Hardware Conceptual Overview
Figure 3-1
Chapter 3 Slide 4
Computer DevicesComputer 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 5
Computer DevicesComputer 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 6
Computer DevicesComputer Devices
Input, output, and communications devices
• Transfer data between a computer and its users or other computers
Storage devices• Save data for later processing
Chapter 3 Slide 7
Uses of Input HardwareUses 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.
Chapter 3 Slide 8
Input DevicesInput 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 9
Input DevicesInput 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 10
Input DevicesInput 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 11
Processing Hardware – The Execution CycleProcessing Hardware – The Execution Cycle
Figure 3-5
Chapter 3 Slide 12
Measuring Processing PowerMeasuring Processing Power
Word length and bus width Speed of arithmetic Instruction speed Instruction set Pipelining
Chapter 3 Slide 13
Processing HardwareProcessing 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
Chapter 3 Slide 14
Processing TrendsProcessing Trends
Moore’s Law• A 1965 prediction by Gordon Moore, a co-
founder of Intel, that the amount of information storable in a square inch of silicon would double about every 18 months
Chapter 3 Slide 15
Types of Storage HardwareTypes 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
Chapter 3 Slide 16
Types of Storage HardwareTypes of Storage Hardware
Volatile storage• Requires electrical power to retain its data
Non-volatile storage• Retains its data in the absence of electrical
power
Chapter 3 Slide 17
Primary Storage DevicesPrimary Storage Devices
Cache memory• Expensive super-fast primary storage
RAM (random access memory)• Volatile primary storage
ROM (read-only memory)• Non-volatile primary storage
Chapter 3 Slide 18
Secondary Storage DevicesSecondary Storage Devices
Fixed media• Hard disk• RAID
Removable media• Includes diskettes, cartridge disks,
magnetic tape, optical media, and flash memory
Chapter 3 Slide 19
Other Storage TechnologiesOther Storage Technologies
Distributed Storage• Storage Area Networks (SANs)
Volumetric Storage• Holographic• MFD
Chapter 3 Slide 20
Hardware for Data OutputHardware 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.
Chapter 3 Slide 21
Types of Software - OverviewTypes of Software - Overview
Figure 3-12
Chapter 3 Slide 22
Types of SoftwareTypes 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
Chapter 3 Slide 23
Types of SoftwareTypes 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
Chapter 3 Slide 24
Vertical Software IssuesVertical Software Issues
Make vs. Buy• Custom• Customized• Packaged (COTS)
Integration• Enterprise Resource Planning (ERP)• Middleware
Chapter 3 Slide 25
Horizontal Software TypesHorizontal Software Types
Office Automation Business Function Application
• Examples: Sales force management, Human resources management, Inventory management, Bookkeeping
Chapter 3 Slide 26
Systems SoftwareSystems Software
Operating System Kernel Systems Utilities Network and Systems Management
Software
Chapter 3 Slide 27
Systems Development Software – Language DifferencesSystems Development Software – Language Differences
Language Translation Method• Interpreted• Compiled
Level of Abstraction Procedural vs. Non-Procedural Command/Data Oriented vs. Object
Oriented
Chapter 3 Slide 28
A Layered View of SoftwareA 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
Chapter 3 Slide 29
Client/Server ModelsClient/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
Chapter 3 Slide 30
Client/Server ModelsClient/Server Models
Three-tiered model• 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 31
Peek Into The Future – NanotechnologyPeek 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
Chapter 3 Slide 32
Peek Into The Future – Artificial IntelligencePeek 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
Chapter 3 Slide 33
Peek Into The Future – Artificial IntelligencePeek 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
End of Chapter 3End of
Chapter 3
Computer Hardware And Software