Title: COMPUTER SOFTWARE
1COMPUTER SOFTWARE
- EDIT Module 1 Introduction to Information
Technology
2- Think of a computer as a robot.
- What do you want it to do?
3We 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.
4For the computer to be able to perform all these
requires the user to instruct the computer
software to control the machine
5Why 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.
6Important 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.
7Computer 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.
8Overview of Computer Software
9Trends 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
10Application 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
11Application SoftwareEnd User Applications
- 2) Application-Specific Programs
- Application Software Packages support managerial
and operational uses - Accounting
- Transaction Processing
- Customer Relationship Management
- Electronic Commerce
12System SoftwareComputer System Management
- 1) System Management Programs
- Operating System
- Resource Management
- File Management
- Task Management
- Network Management Programs
- Database Management Systems
- System Utilities
13System 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.
14Programming Languages
15In 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
16Systems Software
- Definition
- All programs related to coordinating computer
operations - Components
- Operating System
- Utility programs
- Program language translators
17Operating 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
18Operating 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)
19Functions of an Operating System
Use of hardware resources
Managing the accomplishment of tasks
Managing Data and Program Files
Sort, Merge, Performance, etc.
20Functions 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
21Operating 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.
22User 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
23Popular Operating Systems
- DOS
- Windows .X
- Windows NT
- UNIX
- Linux
- OS/2
- Mac OS
- IBM MVS, VM
24OS 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
25What is the platform of your system?
- A common question posed to a system vendor,
manufacturer or even the organization utilizing
the system..
26Platform
- Definition
- Computer hardware and operating system software
that dictate what other software can run - E.g. Wintel
- Intel-based PC running on
- Microsoft Windows
27Types of OS
- Command line
- Single user PC
- Network Operating System (NOS)
28Command-line MS-DOS
- Command-line interface
- Prompt system is waiting for you to do
something - Key a command
- Not user-friendly
29Single-user PC Microsoft Windows
- Graphical user interface
- Eases access to the OS
- Most new computers come with Windows already
installed
30Network 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
31NOS 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
32Early Days of Windows OS
- Operating environment for MS-DOS
- Shell layer added between users and DOS
33Windows 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
34What are the prominent features of Windows?
35Prominent feature of Windows GUI
- On-screen pictures
- Icons
- Menus
- Pull down
- Pop up
- Click to activate a command or function
- Fast
- Easy
- Intuitive
36Windows 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)
37Windows 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
38Improved Windows Features
- Backup
- Interfaces with other software
- Networking features
- Security
- Dr. Watson
39Windows
- Helps reduce the cost of owning and maintaining a
PC
40Windows 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
41Windows 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
42Windows 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
43Windows 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
44Windows 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
45Windows 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
46Windows 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
47Windows CE Consumer Electronics
- Subset of Windows
- Less memory
- Smaller screens
- Little or no file storage
- Provides Internet connectivity
48Mac OS
- First commercially successful GUI (1984)
- Served as a model to other GUI systems
49UNIX
- 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
50LINUX
- 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
51LINUX
- Advantages over Windows
- Extremely stable
- Internet support
- Reinstallation is simpler
- Disadvantage
- Scarcity of applications
52Large 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
53Sharing 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
54Memory Management
- The process of providing separate memory space to
programs - Memory Protection keeps one program from
interfering with another
55Sharing 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
56Utility Programs
- Come with System Software
- Handle special needs
- Perform secondary chores
- Do not need to be memory resident
57Functions 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
58Are all operating systems the same?
- Features and functions.
- Advantages and benefits.
From Personal Computers to Mainframes?
59Summary
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.