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Created By Manish Mathur
Information Technology
Created By Manish Mathur
Table of Contents
S. No. Chapter Name
1. Computer Software
2. Data Storage, Retrieval and DBMS
3. Computer Network and Network Security
4. Internet and Other Technologies
5. Flowchart
6. Decision Table
Created By Manish Mathur
Chapter [1]
Computer Software
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Software are the means by which hardware of the computer can be controlled. In other words whatever we feed to computer as input and obtain from computer as output is called software.
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System SoftwareA set of programs designed ~
• To operate and control computer hardware.
• To provide platform for running the application software.
HardwareSystem softwareApplication softwareUser
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System Software
Programming Langu
age
Operating System
Device Driver
Utility Program
Language Translator
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Computer Language
[1] Machine Language Language of 0’s and
1’s. Regarded as first
generation language Machine dependent
Advantages :~• No Translation Required.• Speed of processing is fast.
Disadvantages :~• Difficult to learn, understand
and use.• Very Bulky.• Not common to all types of
computers.
[2] Assembly Language Language of codes &
symbols. Regarded as second
generation language Machine dependent
Advantages :~• Relatively easy to learn & use.• Less bulky.
Disadvantages :~• Requires translation.• Slow processing speed.• Not common to all types of
computers.
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[3] High Level Language
No codes, only symbols
Procedural Language. Regarded as third
generation language Machine independent
Advantages :~• Very easy to learn & use.• Very less bulky.• Common to all types of
computers
Disadvantages :~• Requires translation.• Slow processing speed.
[4] 4GLs Non-Procedural
Language. Types :~
Product Oriented 4GLs User Oriented 4GLs
Product User
Technical Non-technical
Complex Simple
Used by both end-user & Professionals Professional
To make large To make small software programs
Ideal, Natural-2 Focus, RAMIS
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[5] 5GLs
Based on solving the problem using
factors/constraint given to the program.
Used mainly in Artificial Intelligence, neural network
and draw inferences from the large databases.
ProLog, Mercury etc
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Other Programming Language In the traditional approach software development suffer from the
following problems –
Takes years to complete Programmer’s productivity is low Debugging is difficult Large program, needs large memory and are slow
Solution to these problems is in the dev. of S/w using OOP approach. In OOP the problem is divided into pieces and a separate program is
written for each piece of the problem. The program so written is called object and the approach is called OOP.
Object is a small program code written and tested separately and provide “Re- usability”.
Advantages :~Provide GUI Faster development of programIncreased productivity Less programming staff neededLess errors Re-usability
Disadvantage :~High development cost High startup timeSlow program High memory consumption
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Operating System
• Also known as Executive system, Control system, Monitor system.
• Large collection of programs readymade available.
• Most important program which must be present in the memory of computer when it is ON.
• Loading OS in the computer’s memory is called “Booting”.
• It acts as a bridge between user and computer.
• MS-DOS, Windows, UNIX, LINUX, OS/2 etc.
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Functions :~Functions :~
• Program Execution
• Enabling Multi-
user
• Memory
Management
• Interrupt
Handling
• System Security
• Fault Monitoring
• File Management
• Job Scheduling• Processor
Management• Usage record• User Interface• Virus checking
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OS for Micro Computers
PC/MS-DOS :~
Originally developed by Seatle Computer Products, USA Taken over by Microsoft and IBM, launched in 1980 by the name PC-
DOS. Re-launched by Microsoft alone by the name MS-DOS. Features –
• 16 bit OS• Single user• Single tasking• CUI
MS-Windows :~
Initially launched in 1983 then re-launched 1991. Features –
• 16 bit OS• Single user• Multi tasking• GUI
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Windows 95 :~
Launched in 1995. Features –
• 32 bit Architecture• Capable of accessing 4GB
RAM• Multitasking• GUI (single click)• Network ready
Windows NT :~
Called windows with new Technology.Regarded as OS for network server.
Features –
• 32 bit OS• Multi tasking• Multi User• GUI• Network
enabled
• Enhanced security facility• High memory requirement• High processor requirement• Expensive• Portability
OS/2 :~Launched by IBM + Microsoft in 1987
Demerits –
• Slow Booting
• No support to existing application
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UNIX :~
Launched in 1969 by AT&T Labs USA. Features –
• Portable, Multi-User, Multi-tasking OS• Uses plain text to store data• Treat devices as file• In-built programming support with command line
interpreter.• Small size (UNIX V7 occupies less then 10MB)• Formed backbone of the Internet• Linux is advanced, GUI version of UNIX.
Mac OS :~
Dev. By Apple Inc., in 1984 for their Macintosh computers. Features –
• Completely GUI based• Multi-tasking• Many server programs (Samba, DNS, SMTP etc)• poor memory management• conflict with OS extensions
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Features of OSTechniques of combining the processing work of multiple users in such a manner that achieves the highest resources efficiency is called “Interleaving techniques”.
Interleaving
techniques
MultiProgramming
Multi Thread
ing
MultitaskingVMS
Multiprocess
ing
Time Sharing
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Multi-Programming :~
P1
P2
P3
Input Output
Stores multiple program in the memory but runs only one at a time.
Concurrent Execution. Uses Buffers to manage I-O-P operations
simultaneously by single control unit. Creates memory partitions to store programs
separately.
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Multi-Threading :~
Used by web servers to run the same process multiple times to serve multiple clients
concurrently. It allows a process to keep running even if some
threads are halted, awaiting user interaction, working on a lengthy task,
It increases responsiveness, resource sharing.
Multi-Tasking :~
Two or more tasks can be executed simultaneously.
Types -
Single user Multi tasking.
Multi user Multi tasking.
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Virtual Memory Systems :~
“Virtual memory” is the memory which actually does not exist.
It is a part of external memory that acts as an internal memory.
It gives illusion that it has unlimited main memory.
VMS is based on the concept of virtual memory.
It divides the program into pages. During program execution first few
pages are loaded into main memory and rest resides in the virtual memory.
The pages keep moving in and out from main memory as and when
required. This process is called “Overlaying”.
VMSRAM
Hard DiskRAM
pieces of
program
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Multi-Processing :~
It stores multiple program in the memory and executes them simultaneously.
It requires multiple CPUs to be present in the
computer.Time Sharing :~
CPU time is divided into a small time slot called Time Slice .
Each process is executed for a time slice only and then CPU shifted to other.
Shifting of CPU is so rapid that the user can’t even notice it.
It reduces the response time of computer but requires large memory.
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Device driver
Small files that acts as interface between hardware and OS.
When Calling programming invokes a routine in the driver, the driver issues a command to the device to perform the user
task.
Mouse, Keyboard, Printer, Web camera, Pen drive, Audio devices, Scanner etc. all requires device driver.
Many OS today comes with many standard built-in device drivers.
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Utility Program A subroutine which is ready made available in the market
program.
Examples –
• Sorting Utility, Text Editors, OS Utility,
• Spooling softwareSimultaneous Peripheral Operation On Line. This s/w is to compensate the speed difference between CPU and I/O devices. It utilizes Output spool area and Input spool area to do processing along with I/O.
• Debugging programThis program traces the execution of the software being debug to search errors. MSD (Micro Soft Diagnostic) is a tool provided by Microsoft for debugging user programs.
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Language Translator
converts Source code into Object code.
Types –
• Assembler : Assembly language Machine language• Compiler : High level language Machine language
• Interpreter : High level language Machine language
Compiler Interpreter
Entire program at once Line by line
Display list of errors Display errors one by one
Object code on disk In the main memory
Fast Slow
Required only first time Every time
Expensive Less expensive
e.g. Cobol, C, C++ e.g. BASIC
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General Purpose SoftwareGeneral Purpose Software Also known as Package, these are the programs which are –
ready made available. used to solve several problems used commonly by many users.
3 categories – Commercial S/w Shareware S/w Open Source S/w
Examples – Word Processor DBMS Internet Browsers e-mail client program
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Application Software
These are the programs which are –
specifically written by programmer. used to solve one particular problems. used uniquely by one user.
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Some General PurposeSoftware
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Enterprises Resource Planning (ERP)
An information processing system that brings all the resources of an organization together and integrate business operations and information flow, to synergies the resources of the organization.
Fully integrated system covering all functional areas of enterprises.
It offers single, unified database for the various modules.
Various modules in an ERP includes –Manufacturing, Marketing, Accounting, Costing, Human resource, Supply chain etc.
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Decision Support System (DSS)
DSS is an information processing system to assist managers in decision making process
Characteristics :~
Support decision making Solve relatively un-structured problems User friendly interface
Components :~
USER Planning Language
Database
Model base
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Artificial Intelligence It is a software that tries to emulate human behavior
such as reasoning, seeing, hearing, communicating etc.
Types :~ Natural Language, Voice Recognition,
Robotics, Neural Network.
Natural Language resemble human language in
command and their format. Combined with voice
recognition they provide most user friendly and natural
way of interaction between user and system.
Robotics focuses on the machines that replaces human
labour.
Neural networks aimed to improve decision making.
They are found in E-commerce applications.
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Expert System• ES is a decision making system that helps managers by providing them
ready made decision.
• Components :~
(i) Knowledge base (ii) Inference Engine
(iii) User Interface (iv) Explanation Facility
(v) Knowledge acquisition facility
User User Interface Knowledge BaseInference Engine
Explanation Facility
Knowledge acquisition facility
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• Types :~– Example Based– Rule Based– Frame Based
• Benefits :~– Cost effective alternative to human expert– Better then an expert– Faster, consistent– Better quality decision– Preserve the knowledge of an expert
• Limitations :~– Development is costly and time consuming– Difficult to obtain knowledge from an expert– Fails when presented with the problem, not programmed.
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