unit 2 foc
Post on 20-Jan-2015
1.005 Views
Preview:
DESCRIPTION
TRANSCRIPT
UNIT -2
COMPUTER SOFTWARE
INTRODUCTION• SOFTWARE• HARDWARE• DIFFERENCE BETWEEN THE S/W
AND H/W
TYPES OF SOFTWARE
APPLICATIONSYSTEM
SOFTWARE
SOFTWARE
• Application software
-Easy-to-use programs designed to perform specific tasks.
• System software-Set of programs designed to operate and control the computer.
OPERATING SYSTEM
• It is a collection of programs that controls and manages the computer
• ExamplesWindows, Unix, MSDOS
Functions Of OS• It provide an interface between the hardware
and the user.• It controls and co-ordinate the entire computer
system.• It controls the allocation and use of various
resource by various user and task.• It controls the various application programs.• Scheduling the jobs.• Process management, Memory management,
Device management etc,.
TYPES OF OS
• Single user/ single tasking OS
• Single user/ multi tasking OS
• Multi user/ multi tasking OS
• Time sharing OS
• Virtual storage OS
• Real time system
Single user/Single tasking OS
• One user works on the system
• Performs one task at a time
• Take up little space on disk
• Run on inexpensive computers
• Example MS-DOS
Single user/Multitasking OS
• User performs many tasks at once
• Most common form of OS
• Require expensive computers
• Tend to be complex
• Example: Windows XP
Multi user/Multitasking OS
• Many users connect to one computer
• Each user has a unique session
• Maintenance can be easy
• Requires a powerful computer
• Example: UNIX, Linux, etc,.
Time sharing OS
• It handles multiple jobs at a time.
• It switches the CPU among various jobs that are running on the computer whenever there is a program break or a fixed time has expired.
Virtual storage OS
• It uses the technique Demand paging. i.e. whenever the program size is larger than the main memory it splits the program into many pages.
• Only the needed page is loaded to the main memory for execution.
Real-time operating system
• It gets data from an on going event.
• Respond quickly to user input.
• Example: Reservation system
LOGICAL SYSTEM ARCHITECTURE
HARDWARE
• The physical components present in the computer is called Hardware.
• Example: Keyboard, Monitor etc,.
SOFTWARE
• It is a collection of programs which, performs some task.
• System s/w
• Application s/w
System S/W
• It is collection of programs that controls and manage the computer.
• Types:OS,Language processor etc,.
TYPES OF SOFTWARE
APPLICATIONSYSTEM
SOFTWARE
Example:Operating system,Device drivers,Language Processor,System utilities etc,.
Example:Ms-Office,Reservation system,Payroll processing systemHospital management system etc,.
GENERALCUSTOMISED
OS
• It is a collection of programs that controls and manages all the components present in the computer
Device drivers• It is set of programs, which act as an
interface between the computer and the device.
• It is responsible for the proper functioning of the device.
COMPUTER
DRIVERS
DEVICE 1
DEVICE 2
DEVICE n
Language Processor
• It is a system s/w that translates the programs written in High level language to Machine language.
• Machine language: 0’s and 1’s.
• High level language: C, C++, Java etc,.
Example: Compiler, Interpreter, Assembler
Compiler
• It converts the programs written in high level language to machine language i.e. it translates the source code to object code.
HIGH LEVEL LANGUAGE
COMPILER
MACHINE LANGUAGE
Interpreter
• It converts the programs written in high level language to machine language.
• It executes the source code in line-by-line manner. I
NTERPRETRE
HIGH LEVEL LANGUAGE
MACHINE LANGUAGE
Assembler
• It converts the programs written in Assembly language to machine language.
ASSEMBLER
ASSEMBLY LANGUAGE
MACHINE LANGUAGE
System Utilities
• These programs performs tasks related to the maintenance of computer– Example: Disk clean-up.
APPLICATION SOFTWARE
• It is collection of programs that performs a specific task.
– Customised
– General
APPLICATION SOFTWARE (Cont)
• Customised Application s/w It is developed to meet the requirements of
limited user.
• General Application s/w It is developed to meet the requirements of
many user.
S/W Terminologies• Firmware
It is a software, which is permanently stored on the memory
Eg: BIOS• Open source
• It is software developed by some programmers and released for public use
• The programming code is available so that the user can modify it.
S/W Terminologies (Cont)• Freeware
• It is a copyrighted software which is given away free by the owner.
• Commercial s/w
• It is developed by business organizations to earn profit
SYSTEM DEVELOPMENT LIFE CYCLE
Steps:
• Requirement analysis
• Design
• Coding
• Testing
• Implementation & maintenance
SDLCRequirement
Analysis
Impl & Maintenance
Testing
Coding
Design
Requirement analysis
• It produce the Software requirement document (SRS),which specifies all requirements of the customer.
Design
• It is the process of designing how the requirements to be implemented.
Coding
• It is the process of developing code for the software.
Testing
• It is the process of executing the software with sample data to verify whether it has errors or not.
Implementation & maintenance
• It involves installation of the s/w, giving training to the customer etc,.
ASSIGNMENT
DECIMAL ↔ BINARY
• 29
• 68
• 116
• 202
• 423
DECIMAL ↔ OCTAL
• 27
• 171
• 262
• 726
• 3731
DECIMAL ↔ HEXA
• 83
• 796
• 2947
• 4321
• 8239
DECIMAL ↔ OTHER
• 85 ↔ BASE4
• 76 ↔ BASE3
• 317 ↔ BASE6
• 186 ↔ BASE7
• 251 ↔ BASE8
BINARY ↔ OCTAL,HEXA
• 1110111
• 1100001001
• 10010101101011
• 101011110001
• 10110101011
OCTAL ↔ HEXA
• 567
• 649
• 814
• 2457
• 4948
• 61.62510 BASE2
• 427.2910 OCTAL
• 759.3710 HEXA
INTERNET
• Network of networks i.e. interconnection of networks.
EVOLUTION OF INTERNET
• In 1960 US Dept of Defense created a network called ARPANET (Advanced Research Project Agency Network).It is the forerunner of today’s Internet.
• By 1970’s ARPA helped in the development of TCP/IP (Transmission Control Protocol/Internet Protocol) which is used for transferring of data between networks.
• In 1980’s National Science Foundation (NSF) created the NSFNET.
• In 1980’s e-mail was introduced.
• In 1990’s the world wide web was introduced.
Internet Terminology
• Webpage – It is an electronic document which contains information.
• Website – It is a collection of related WebPages.
• Homepage – It is starting point or doorway to the website. It is also known as the index page.
Internet Terminology (Cont)
• Web Browser or Browser – It is a program that enables the user to access the Webpage and displays the webpage on the computer screen.
• Uniform Resource Locator (URL) –It is the unique Address of the Webpage, which is used to identifies its location on the internet.
Internet Terminology (Cont)
• Hypertext – It refers to the text that connects other documents.
• Internet Service Provider (ISP) - It provides access to the internet to user.
• Web Server – It is a computer that services the requests from the clients i.e. web browser
Internet Terminology (Cont)
• Download - It is the process of receiving data from a remote computer to the local computer.
• Upload – It is process of sending data from local computer to remote computer.
Getting connected to the Internet
Requirements
• Modem
• A Connection with the ISP
IP Address
• The Internet Protocol Address is used for identifying the computer.
• It can be expressed in dotted decimal form or binary form.
• It has four octets i.e. it has four 8 bit number Eg: 175.192.0.110101111.11000000.00000000.00000001
DNS
• Domain Name System
• It is used to maps the text to the IP Address.
URL
• Uniform Resource Locator.
• It contains the protocol name, domain name etc,.
• Eg: http://www.microsoft.com
Internet Application
• World Wide Web
It is a collection of information or collection websites.
It is used to send electronic message to anyone.
Internet Application (Cont)
• Chatting
• It is online Conversation.
• It is used to send message back and forth to anyone.
• Remote Access
• It is the process of accessing information present in a remote computer.
Internet Application (Cont)
• File Sharing
• It enables a group of user to share information.
• The information has been placed on a shared location and the user access the information.
Internet Application (Cont)
• IRC
• Internet Relay Chat.
• It is designed for group communication.
• Video Conferencing
• It allows two or more user to interact via video and audio transmission.
Internet Application (Cont)
• FTP
• File Transfer Protocol
• It is used to transfer data from one computer to another computer.
• TelNet
• Telecommunication Network
• This protocol is used to get services from the server.
Internet Application (Cont)
• VOIP
• Voice Over Internet Protocol.
• It sends voice over the internet protocol.
SYSTEM DEVELOPMENT LIFE CYCLE
Requirements – defines needed information, function, behavior, performance and interfaces.Design – data structures, software architecture, interface representations, algorithmic details.Implementation – source code, database, user documentation, testing.
top related