Transcript Chapter 2

Key Slide
The physical
basis of the
infrastructure
Major Concepts
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Hardware and Software 
Software for software (operating systems) 
Software for business (applications) 
Software to create software (programming
languages) 
• Nagging issues about software 

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Principles and Learning Objectives-1
• Users must work closely with IS professionals to
define business needs, evaluate options, and
select the hardware and software that provide a
cost-effective solution to those needs.
– Identify and discuss the role of the essential
hardware components  of a computer system.
– List and describe popular classes of computer
systems  and discuss the role of each.
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Principles and Learning Objectives -2
• When selecting an operating system, you must
consider the current and future requirements for
application software to meet the needs of the
organization. In addition, your choice of a
particular operating system must be consistent
with your choice of hardware.
– Identify and briefly describe the functions of the
two basic kinds of software. 
– Outline the role of the operating system and
identify the features of several popular operating
systems. 
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Principles and Learning Objectives-3
• Do not develop proprietary application software
unless doing so will meet a compelling business
need that can provide a competitive advantage. 
Discuss how application software can support
personal, workgroup, and enterprise business
objectives.
– Identify three basic approaches to developing
application software and discuss the pros and cons of
each.
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Principles and Learning Objectives-4
• Choose a programming language whose
functional characteristics are appropriate for the task
at hand, taking into consideration the skills and
experience of the programming staff. 
– Outline the overall evolution of programming
languages and clearly differentiate among the five
generations of programming languages.
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Principles and Learning Objectives-5
• The software industry continues to undergo
constant change; users need to be aware of recent
trends and issues to be effective in their business
and personal life. 
– Identify several key issues and trends that have an
impact on organizations and individuals.
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Hardware Components
• Central processing unit (CPU) (The thinker)
– Arithmetic/logic unit (ALU)
– Control unit
• Input devices (what purpose?)
• Output devices (what purpose?)
Why are
there two
different
kinds of
input?
MIS 300, Chapter 2
CPU
Control & Data Source
Results & Feedback
Why are
there two
different
kinds of
output?
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Hardware Components (continued)
• Communications devices
• Primary storage devices
• Secondary storage devices
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Hardware Components (continued)
Figure 2.1: Computer System Components
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Processing and Memory Devices:
Power, Speed, and Capacity
• System unit
– Houses CPU and memory
• All other devices are linked to the system unit
• What is the advantage of this?
• How do we measure the “strength” of a computer?
See next slide.
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Processing Characteristics and
Functions
• Machine cycle time: time to execute the instruction
phase and the execution phase
• Clock speed: electronic pulses produced at a
predetermined rate
• Wordlength: number of bits that can be processed
at one time
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Processing Characteristics and
Functions (continued)
• Physical characteristics of the CPU
– Digital circuits on chips
– Electrical current flows through silicon
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Memory Characteristics and Functions:
Storage Capacity – A lesson in Greek
Table 2.1: Number of Bytes
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Types of Memory
• Random access memory (RAM)
– Temporary
– Volatile
• ROM (read-only memory)
– Usually nonvolatile
• SEDOM (Student Exam Dump Only Memory)
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Multiprocessing – Doing more than one
Thing at a Time
• Multiprocessing: simultaneous execution of two
or more instructions
• Parallel processing: linking hundreds or
thousands of processors operating in parallel
• Grid computing: collection of computers
working to solve a common problem
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Secondary Storage and Input and
Output Devices
• Secondary storage
– Also called permanent storage
– Nonvolatile
– Greater capacity and greater economy than memory
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Secondary Storage Access Methods
• Sequential access: records must be retrieved in
order
– Sequential access storage devices (SASD)
• Direct access: records can be retrieved in any
order
– Direct access storage devices (DASDs)
Can this matter at all? What problems are being
solved here? What problems are being created?
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Secondary Storage Devices
• Magnetic tapes
• Magnetic disks
• Redundant array of independent/inexpensive disks
(RAID)
• Compact disc read-only memory (CD-ROM)
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SAN
• Storage area network
• Provides high-speed connections between datastorage devices and computers
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SAN (continued)
Figure 2.4: Storage Area Network
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Secondary Storage Devices
(continued)
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CD-recordable (CD-R) discs
CD-rewritable (CD-RW) discs
Digital versatile disc (DVD)
Memory cards
Expandable storage
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Input Devices
• Personal computer input devices
– Keyboard
– Mouse
• Voice-recognition devices
• Terminals
• And what else? What can you imagine?
What are people like as input devices?
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Input Devices (continued)
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Touch-sensitive screens
Bar-code scanners
Optical data readers
Point-of-sale (POS) devices
Automatic teller machine (ATM) devices
What problem(s) is (are) these sorts of devices
trying to solve?
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Input Devices (continued)
• Magnetic ink character recognition (MICR) devices
• Radio-frequency identification (RFID) – Go ask
Walmart
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Output Devices
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Display monitors
Liquid crystal displays (LCDs)
Organic light-emitting diodes (OLEDs)
Printers and plotters
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Output Devices (continued)

CRT monitors are large and bulky in comparison to LCD
monitors (flat displays). Who knows what the future will bring?
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Computer System Types
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Handheld computers (ideal for ….?)
Portable computers (solves what problem?)
Thin client (saves what?)
Desktop computers (how much longer?)
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Computer System Types (continued)
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Workstations
Servers
Mainframe computers
Supercomputers
Superdupercomputers?

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Overview of Software
• Computer programs: sequences of instructions
• Documentation: describes program functions
• Systems software: coordinates the activities of
hardware and programs: “To serve and protect”
• Application software: helps users solve
particular problems: “To get the job done”
What is software really doing? Why is it
important?
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Supporting Individual, Group, and
Organizational Goals
• Sphere of influence: the scope of problems and
opportunities addressed by a particular organization
– Personal
– Workgroup
– Enterprise
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Table 2.5: Classifying Software by Type and Sphere of Influence
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Systems Software: Operating Systems
• Operating system (OS): set of programs that
control and manage the hardware and act as an
interface with applications
• Common hardware functions
– Get input (e.g., keyboard)
– Retrieve data from disks and store data on disks
– Display information on a monitor or printer
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Operating Systems (continued)
Figure 2.8: The role of the operating system and other systems
software is as an interface or buffer between application
software and hardware. It also controls and manages
everything.
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Operating Systems (continued)
• User interface
– Allows individuals to access and command the
computer system
– Command-based user interface: uses text
commands
– Graphical user interface (GUI): uses icons and
menus to send commands to the computer system
– Smart interface: anticipates users’ needs
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Operating Systems (continued)
• Hardware independence
– Application program interface (API): allows
applications to make use of the operating system
• Memory management
– Control how memory is accessed and maximize
available memory and storage
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Operating Systems (continued)
• Processing tasks
– Multitasking: more than one program running at the
same time
– Time-sharing: more than one person using a
computer system at the same time
– Scalability: ability to handle an increasing number of
concurrent users smoothly
• Networking capability: features that aid users in
connecting to a computer network
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Operating Systems (continued)
• Access to system resources
– Protection against unauthorized access
– Logons and passwords
• File management
– Ensures that files in secondary storage are
• Available when needed
• Protected from access by unauthorized users
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Current Operating Systems
Table 2.6: Popular Operating Systems Across All Three Spheres of
Influence
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Workgroup Operating Systems
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Windows Server
UNIX
NetWare
Red Hat Linux
Mac OS X Server
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Enterprise Operating Systems
• z/OS
• MPE/iX and HP-UX
• Linux
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Operating Systems for Small
Computers and Special-Purpose
Devices
• Palm OS
• Windows Embedded
• Windows Mobile

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Application Software
• Gives users the ability to solve problems and
perform specific tasks
• Interacts with systems software; systems software
then directs the hardware to perform the tasks
Application
Software
User
Interface
MIS 300, Chapter 2
System
Software
Hardware
Other I/O
Devices
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Types and Functions of Application
Software
• Proprietary software: unique program for a specific
application, usually developed and owned by a
single company
• Off-the-shelf software: purchased software
• Customized package
Proprietary:
“We build it”
MIS 300, Chapter 2
Off-the-Shelf:
“We buy it”
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Personal Application Software
Table 2.8: Examples of Personal Productivity Software
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Personal Application Software
(continued)
Table 2.8: Examples of Personal Productivity Software (continued)
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Workgroup Application Software
• Workgroup application software: supports
teamwork, whether people are in the same location
or dispersed around the world
• Groupware: software that helps groups of people
work together more efficiently and effectively
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Enterprise Application Software
• Software that benefits an entire organization
• Enterprise resource planning (ERP) software:
programs that manage a company’s vital business
operations for an entire multisite, global organization
• ERP integrates across functions, destroying silos
and making communication easier.

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Programming Languages
• Sets of keywords, symbols, and a system of rules
for constructing statements
• Allow humans to communicate instructions to be
executed by a computer
• Syntax: a set of rules associated with a
programming language
• Different languages have characteristics that make
them appropriate for particular types of applications
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Programming Languages -2
• A programming language is a vehicle through which
an organization’s need for processing is translated
into commands that will later be executed and
turned into work.
• Programming is a kind of planning for action.
• Programming is always “buggy” in the sense that
people make mistakes and organizational needs are
imperfectly understood.
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Programming Languages -3
I, the
programmer
, hear
you!
I need
Hooray!
informaNow
tion
toI
KNOW!
solve
a
problem!
Saved
Commands
Conversation
about need
Compiler or
language
processor
Information
System
Programming
language
statements

MIS 300, Chapter 2
Information
System
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Software Issues and Trends That Will Effect
YOU!
• Software bugs
– Program defects that keep it from performing correctly
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Copyrights and licenses
Global software support
Obsolescence
Outsourcing
Legal issues
Commoditization
Security
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Summary
• Hardware: central processing unit (CPU), input and
output devices, communications devices, primary
storage devices, and secondary storage devices
• Random access memory (RAM): temporary and
volatile
• ROM (read-only memory): usually nonvolatile
• Multiprocessing: simultaneous execution of two or
more instructions
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Summary (continued)
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Sequential access: records retrieved in order
Direct access: records retrieved in any order
Computer programs: sequences of instructions
Systems software: coordinates the activities of
hardware and programs
• Application software: helps users solve problems
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Summary (continued)
• Operating system (OS): programs that control the
hardware and act as an interface with applications
• Graphical user interface (GUI): uses icons and
menus to send commands to the computer system
• Programming languages: allow humans to
communicate instructions to be executed by a
computer
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