COMPUTER SOFTWARE

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COMPUTER SOFTWARE

• EDIT Module 1 Introduction to Information
  Technology

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• Think of a computer as a robot.
• What do you want it to do?

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We Want a Computer To

• 1. Read input data from source documents or
  secondary storage.
• 2. Process the data.
• 3. Display the results.
• 4. Print the results.
• 5. Store the results.
• 6. Transmit the results.
• 7. Protect itself and the data.
• 8. Keep track of things that it is doing to
  restart.
• 9. Count things to reflect performance.
• 10. Do multiple things at the same time.

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For the computer to be able to perform all these
requires the user to instruct the computer
software to control the machine
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Why is this topic important

• Hardware is the engine and software is the gas
  that makes it run.
• To understand software concepts is to understand
  how real work gets done on computer-based systems
  within a business.
• To understand software is to appreciate the
  specific details that must be addressed for a new
  computer-based application to be implemented.

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Important Topics

• Major categories of software.
• The importance of operating systems and related
  systems software.
• The increasing importance of application
  packages.
• Challenges to implement application packages.
• The evolution of programming languages and the
  reason for so many languages.

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Computer Software

• The detailed instructions that control
• the operation of a computer system.
• Provide tools to people.
• Intermediary between people and data.
• Manage the computer resources.
• Selecting appropriate software for an enterprise
  is a key management decision.

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Overview of Computer Software
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Trends in Computer Software
First Generation
Second Generation
Third Generation
Fourth Generation
Fifth Generation
Trend Toward Easy-to-Use Multipurpose
Network-Enabled Application Packages for
Productivity and Collaboration
User-Written Programs Machine Languages
Packaged Programs Symbolic Languages
Operating Systems High-Level Languages
DBMS Fourth- Generation Languages Microcomput
er Packages
Natural Object-Oriented Languages Multipurpo
se Graphic- Interface Network-enabled
Expert-Assisted Packages
Trend Toward Visual or Conversational
Programming Languages and Tools
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Application SoftwareEnd User Applications

• 1) General Purpose Application Programs
• Software Suites Microsoft Office
• Word Processing - Word / Works / Claris
• Spreadsheet Excel / FoxPro / Lotus
• Database Managers - Access / Dbase/Sybase
• Web Browsers Internet Explorer / Netscape
• Electronic Mail MS Outlook / Express / Eudora
• Presentation Graphics Power Point / Flash

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Application SoftwareEnd User Applications

• 2) Application-Specific Programs
• Application Software Packages support managerial
  and operational uses
• Accounting
• Transaction Processing
• Customer Relationship Management
• Electronic Commerce

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System SoftwareComputer System Management

• 1) System Management Programs
• Operating System
• Resource Management
• File Management
• Task Management
• Network Management Programs
• Database Management Systems
• System Utilities

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System SoftwareComputer System Management

• 2) System Development Programs
• Programming Language
• - BASIC / C / COBOL / JAVA/TURBO-PASCAL
• Programming Translators
• Assemblers translates assembler language
• Compilers translates high level language
  translate the program (source code) into machine
  code (object code), then execute the object code.

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Programming Languages
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In short

• Operating Systems
• Five basic functions
• User interface
• Resource Management
• File Management
• Task Management
• Utilities for support services
• Programming Languages
• Five major levels
• Machine language
• Assembler language
• High-level language
• Fourth-Generation
• Object-Oriented

• Software
• Application vs. System
• Application Software
• General purpose applications for end users
• System Software
• Manage hardware, software, network, data
  resources

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Systems Software

• Definition
• All programs related to coordinating computer
  operations
• Components
• Operating System
• Utility programs
• Program language translators

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Operating SystemHidden Software

• Definition provides access to all resources
• Kernel
• Manages the operating system
• Memory resident
• Loads set of programs that lies between
  applications software and the hardware
• Fundamental software that controls non-resident
  portions of the OS as needed
• Booting Loads the kernel into memory

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Operating System

• A software program that acts as an intermediary
• between a user of a computer and the computer
• hardware.
• Exist because it is a reasonable way to solve the
  
• problem of creating a usable computer by better
• managing the computer resources.
• The basis for standardization of application
• software. (the platform)

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Functions of an Operating System
Use of hardware resources
Managing the accomplishment of tasks
Managing Data and Program Files
Sort, Merge, Performance, etc.
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Functions of OS

• Manage the computers resources
• CPU
• Memory
• Disk drives
• Printers
• Establish a user interface
• Execute and provide services for applications
  software
• Carries out all input and output operation

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Operating System Functions

• Multiprogramming - executing two or more
• programs concurrently using the same computer.
• Multiprocessing - executing two or more
• instructions simultaneously in a single computer
  by
• using multiple central processing units.
• Graphical User Interface (GUI) - part of the
• operating system that uses graphic icons to issue
  
• commands and make selections.

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User Interface

• Facilitates communication between the user and
  the operating system
• Two forms
• Command line
• Text-based
• Key commands
• Examples MS-DOS, Unix
• Graphical user interface (GUI)
• Visual images
• Menus
• Examples Windows, Mac OS, Linux

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Popular Operating Systems

• DOS
• Windows .X
• Windows NT

• UNIX
• Linux
• OS/2
• Mac OS
• IBM MVS, VM

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OS is Hidden

• User interested in application software to make
  the PC useful
• Application software is platform specific
• User must be aware of the type of OS
• User should be aware of the functions of OS

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What is the platform of your system?

• A common question posed to a system vendor,
  manufacturer or even the organization utilizing
  the system..

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Platform

• Definition
• Computer hardware and operating system software
  that dictate what other software can run
• E.g. Wintel
• Intel-based PC running on
• Microsoft Windows

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Types of OS

• Command line
• Single user PC
• Network Operating System (NOS)

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Command-line MS-DOS

• Command-line interface
• Prompt system is waiting for you to do
  something
• Key a command
• Not user-friendly

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Single-user PC Microsoft Windows

• Graphical user interface
• Eases access to the OS
• Most new computers come with Windows already
  installed

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Network Operating System NOS

• Designed to permit computers on a network to
  share resources
• Examples
• Windows 2000 Server
• Novell Net Ware
• Provides
• Data security
• Troubleshooting
• Administrative control

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NOS Functions

• Split between client and server computers
• Server
• File management
• Client
• Requests to the server
• Messaging
• Has own local OS
• Makes the resources appear as if they are local
  to the clients computer

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Early Days of Windows OS

• Operating environment for MS-DOS
• Shell layer added between users and DOS

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Windows Today

• Home/consumer market
• Windows 95
• Windows 98
• Windows Millennium Edition (ME)
• Corporate market
• Windows NT
• Windows 2000
• Windows XP
• Pocket computers and Internet appliances
• Windows CE

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What are the prominent features of Windows?
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Prominent feature of Windows GUI

• On-screen pictures
• Icons
• Menus
• Pull down
• Pop up
• Click to activate a command or function
• Fast
• Easy
• Intuitive

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Windows 95 and 98

• Self-contained OS
• DOS commands still available
• Start programs by
• Start button
• Double clicking the icon
• Task bar permits movement between open programs
• Long file names up to 255 characters
• Plug and play
• Object linking and embedding (OLE)

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Windows 98 Additions

• Internet / intranet browsing
• Support for DVD and additional multimedia
  components
• Support for large hard drives
• TV viewer and broadcast ability
• Wizards / Help Assistant

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Improved Windows Features

• Backup
• Interfaces with other software
• Networking features
• Security
• Dr. Watson

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Windows

• Helps reduce the cost of owning and maintaining a
  PC

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Windows MEMillennium Edition

• Multimedia support -- Windows Media Player 7
• Jukebox
• Record music CDs as digital files
• Windows Movie Maker
• Basic video editing
• Windows Image Acquisition
• Scanner and digital camera

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Windows MEMillennium Edition

• Reliability Features
• System File Protection
• AutoUpdate
• System Restore
• Help Center
• Home Network Support
• Wizard for connecting multiple computers and
  peripherals
• Multiple users can share a single Internet
  connection

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Windows NTNew Technology

• Engineered for stability
• Strong security
• Versions
• NT Workstation
• NT Server
• Drawbacks
• Lacks support for older Windows and MS-DOS
  software and hardware
• Complex to learn and use
• Requires more memory and processing power

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Windows 2000

• Stability features
• Security features
• Uses simple approach to hardware setup from
  Windows 98
• Versions
• Windows 2000 Professional for individual users
• Windows 2000 for network servers
• Was intended for both the corporate and home use,
  replacing Win NT and Win 98

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Windows 2000

• Complex
• Heavy demand for computer resources
• Improvements over windows NT
• Maintains user preferences
• Self-healing applications software
• Supports Windows 98 file structure
• Uses plug and play
• Provides improved support for laptops

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Windows XP

• Extends Windows ME and provides a more stable
  environment
• Two categories
• Network server
• 3 versions based upon network complexity
• Desktop computer
• 2 versions
• Professional Client
• Personal Client

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Windows CE Consumer Electronics

• Where used
• Embedded systems
• Industrial controllers
• Robots
• Office equipment
• Cameras
• Telephones
• Home entertainment devices
• Automobile navigation systems
• Pocket PC
• Internet appliance market

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Windows CE Consumer Electronics

• Subset of Windows
• Less memory
• Smaller screens
• Little or no file storage
• Provides Internet connectivity

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Mac OS

• First commercially successful GUI (1984)
• Served as a model to other GUI systems

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UNIX

• Supports
• Multi-user
• Time-sharing
• Character-based system
• Command-line interface
• Runs on various processors and many types of
  computers
• Primary OS used on Internet servers

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LINUX

• UNIX-like OS
• Open-source software
• Download it free
• Make changes
• Distribute copies
• Restriction any changes must be freely
  available to the public
• PC Setup
• PC comes with Windows installed
• Install LINUX in a dual-boot configuration

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LINUX

• Advantages over Windows
• Extremely stable
• Internet support
• Reinstallation is simpler
• Disadvantage
• Scarcity of applications

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Large Computers

• Used by many people at once
• OS works behind the scenes so users can share
  resources (hardware software)
• OS must control
• Who gets access to resources
• What keeps the programs from different users from
  getting mixed up with one another

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Sharing Memory

• Program must be in memory to be executed
• Problems
• Programs compete for space
• May have a very large program
• Memory space for each program must not overlap

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Memory Management

• The process of providing separate memory space to
  programs
• Memory Protection keeps one program from
  interfering with another

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Sharing Storage

• Several users need to access the same disk pack
• One wants to write
• Another wants to read
• OS keeps track of the I/O requests
• OS processes I/O requests in order received

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Utility Programs

• Come with System Software
• Handle special needs
• Perform secondary chores
• Do not need to be memory resident

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Functions of Utility programs

• File manager provide access to lists of stored
  files
• Backup and Restore make duplicate copies of
  important files and return the copy to the hard
  drive if needed
• File compression reduces the amount of disk
  space required by a file
• Disk defragmenter reorganize files so they are
  stored contiguously on disk providing for faster
  access
• Device drivers convert operating system
  instructions into commands that are known to a
  specific device

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Are all operating systems the same?

• Features and functions.
• Advantages and benefits.

From Personal Computers to Mainframes?
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Summary
Operating systems are the foundation of a
computer operation.
Operating systems benefits include better
resource utilization, better system performance,
gains in cost-effectiveness and better overall
management of the entire system.
Without operating systems with advanced features
and functions, computing would still be in its
very early stages.