information technology created by manish mathur. table of contents s. no.chapter name 1.computer...

Created By Manish Mathur

Information Technology


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


Chapter [1]

Computer Software


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.


System SoftwareA set of programs designed ~

• To operate and control computer hardware.

• To provide platform for running the application software.

HardwareSystem softwareApplication softwareUser


System Software

Programming Langu

age

Operating System

Device Driver

Utility Program

Language Translator


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.


[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


[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


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


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.


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


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


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


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


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


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.


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.


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


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.


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.


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.


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


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


Application Software

These are the programs which are –

specifically written by programmer. used to solve one particular problems. used uniquely by one user.


Some General PurposeSoftware


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.


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


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.


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


• 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.

information technology created by manish mathur. table of contents s. no.chapter name 1.computer...

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