Information technology final chap 2
-
Upload
manshi-makati -
Category
Technology
-
view
830 -
download
3
description
Transcript of Information technology final chap 2
INFORMATION TECHNOLOGY
Presented By
Manshi Makati
Taught By ,Asha Madam
INTRODUCTION TO INFORMATION TECHNOLOGY
Information Technology is the application of
Computers towards organizing and efficient
retrieval/reporting of information.
Information Technology refers to the creation,
gathering, processing, storing, protecting,
presenting and dissemination of information
using , hardware, software and
telecommunication technology.
WHAT IS INFORMATION TECHNOLOGY (IT)
ANYWAYS ? As defined by “INFORMATION TECHNOLOGY ASSOCIATION OF AMERICA (ITAA)”
“IT includes various types of Computers, Software,
Communications, Facsimile transmissions, &
Electronic conferencing.” By Henry C. Lucas, Jr
“IT is the study, design, development, implementation,
support or management of computer based information
system particularly software's applications & computer
hardware.”
INFORMATION TECHNOLOGY
Information Technology’s prime concern is Information. MIS is concerned with capture, processing and
communication of information. Computers thus form valuable tool in MIS.
TOP PLAYERS IN IT SECTOR
UNDERSTANDING OF COMPUTERS
The word computer comes from the Latin word “computa” which means “to calculate”.
A computer is normally considered as calculating machine that can perform arithmetic operation at a very high speed.
Nowadays computer is used for multiple purposes. Definition : An electronic device which is capable of performing series
of arithmetic and logical operations at a very high speed is called computer.
Memory is an area of computer which holds data that is waiting to be processed, Storing or output.
UNDERSTANDING OF COMPUTERS (CONTD)
HISTORY OF COMPUTERS The history of computer is very old, long and
fascinating. History of computer in the area of technological
development is being considered because it is usually the technological advancement in computers that brings about economic and social advancement.
HISTORY OF COMPUTERS (CONTD)
o A faster computer brings about faster operation and that in
turn causes an economic development. o This will discuss classes of computers, computer evolution
and highlight some roles played by individuals in these developments.
o This emphasizes the need to study history of the computer because a proper study and understanding of the evolution of computers will undoubtedly help to greatly improve on computer technologies.
COMPUTER GENERATION In 1930, Analog computer were introduced. In 1944, H. Aiken at Hayward University USA, developed
Mark-1. It was the first digital computer from IBM. Which spanned 51 feet in length and 8 feet in height. 500
meters of wiring were required to connect each component. If we consider the Generation 0 of computers till 1944,
then computer were mainly special purposes. They were usually designed to do calculation work.
After 1944, people concentrated on the development of general purpose computers which could be used for multiple tasks which are discussed as follow.
COMPUTER GENERATION SYSTEM
First Generation (1946-59)
Second Generation(1957-64)
Third Generation(1965-70)
Fourth Generation(1970-90)
Fifth Generation(1990 till date)
FIRST GENERATION The first general purpose computer of this generation was
constructed in 1946, at the Moore School of Engineering of the University of Pennsylvania, USA by Prof: Presper Eckert and John Mauchly.
The name of that computer was ENIAC. Work on ENAIC started in 1943 and the project was
completed in 1946. In this computer system Vacuum tubes were used. These tubes
were very large in size, due to which the size of computer of that generation was large.
A device to amplify, switch, or modify a signal (by controlling the movements of electrons)
SECOND GENERATION In second generation a new device was discovered, which is
called transistor.a) Transistor is a small electronic device used in computers, radios, televisions, etc
for controlling an electronic current as it passes along a circuit.
b) Transistor were prepared by a British Scientist William Shockley. These transistor were able to move an electronic charge.
Eg : Lower power consumption, smaller, more reliable, cheaper, much lower heat dissipation
During this generation two programming languages were prepared. i.e.
a) FORTRAN which prepared in 1956 by an American Scientist John Backus.
b) COBOL which was prepared by an American women Grace Hopper in 1959.
Computer of second generation are smaller in size then 1st generation computer.
SECOND GENERATION (CONTD) IBM
IBM7094: For scientific application (1962) IBM1401: For business applications (1959)
In 2nd generation, Increase the performance and capacity was found Lowered cost Speed increase as well All this improvement was the result of use of transistor in place of vacuum
tubes.
THIRD GENERATION In this generation microelectronics were introduced which
was the invention of Integrated Circuits (IC’s).
The 3rd generation was based on IC technology. IC is a small Microchip that contains a large number of electrical
connections and performs the same function as a larger circuit made from separate parts.
IC was an advance electronic technology, when a large number of circuit elements are integrated into a very small surface of silicon known as “Chip” then it is called an IC.
IBM System/360 were the first computers to be built entirely with ICs.
THIRD GENERATION (CONTD) Computer of 3rd generation is smaller in size as compared to
previous generation computer. Maintenance cost was low because the chance of hardware
failure was minimum in those computers. The disadvantage of 3rd generation computer was, a very
costly technology required for the manufacturing of IC chip.
Cray-1: $8.8 million, 160 million instructions per seconds and 8 Mbytes of memory
FORTH GENERATION Improvements to IC technology made it possible to integrate
more and more transistors in a single chip In 1970’s SSI, MSI, LSI and VLSI circuits were used at the
place of IC’s. They are also a single silicon chips. SSI (Small Scale Integration): 10-100 MSI (Medium Scale Integration): 100-1,000 LSI (Large Scale Integration): 1,000-10,000 VLSI (Very Large Scale Integration): >10,000
The important point is that with VLSI it became possible to have a full CPU on a single chip, also called a microprocessor.
The first microprocessor was created by Intel in 1971.
FORTH GENERATION (CONTD) So 4th generation computers are those which uses LSI
technology, due to this technology the size of computers becomes very small but highly costly technology is required for the manufacturing of LSI chips.
With the advent of microprocessors it became possible to build “personal computers”1977: Apple II1981: IBM PC
FIFTH GENERATION The computers that used today belongs to the fifth generation
computers which performs parallel processing, multi-tasking simultaneously.
Voice Recognition Artificial Intelligence Natural Languages Simulation
A computer simulation is an attempt to model a real-life situation on a computer so that it can be studied to see how the system works.
Computers of fifth generation are nearly capable to behave like human beings.
These machine are usually equipped with a large main memory.
Software and hardware components have become cheaper The size of computer in 5th generation has become
surprisingly small.
CLASSIFICATION OF COMPUTERS
Computing machines can be classified in many ways and these
classifications depend on their functions and definitions. They can be classified by the technology from which they
were constructed, the uses to which they are put, their capacity
or size, the era in which they were used, their basic operating
principle and by the kinds of data they process. Following are the main types of Computers :-
1. SUPER COMPUTERS
Super computers are used in applications like defence, space exploration, industrial R&D, manufacturing etc,
The supercomputers are the biggest and fastest machines today and they are used when billion or even trillions of calculations are required.
Super computers have capabilities far beyond even the traditional large-scale systems, their speed ranges from 100 million-instruction-per-second to well over three billion.
For this reason, supercomputers may need the assistance of a medium-size general purpose machines (usually called front-end processor) to handle minor programs or perform slower speed or smaller volume operation.
2. MAINFRAME COMPUTERS
Mainframe computers are used for larger business application.
They are relatively slower and smaller than super computers, thus suiting the budget of larger organization.
They are used in business application were originally designed to handle the data processing requirements such as payroll, inventory control & management etc
They are used in complex modeling, or simulation, business operations, product testing, design and engineering work and in the development of space technology.
Large computers can serve as server systems where many smaller computers can be connected to it to form a communication network.
3. MINI COMPUTERS In the 1960s, the growing demand for a smaller stand-alone machine brought about the manufacture of the minicomputer, to handle tasks that large computers could not perform economically.
Minicomputer systems provide faster operating speeds and larger storage capacities than microcomputer systems.
Operating systems developed for minicomputer systems generally support both multiprogramming and virtual storage.
This means that many programs can be run concurrently.
This type of computer system is very flexible and can be expanded to meet the needs of users.
4. MIRCO COMPUTERSLarge-scale production of silicon chips began in 1971 and this has been of great use in the production of microcomputers.
The Microcomputer has the lowest level capacity, the machine has
memories that are generally made of semiconductors fabricated on
silicon chips.
The microcomputer is a digital computer system that is controlled by a
stored program that uses a microprocessor, a programmable read-only
memory (ROM) and a random-access memory (RAM).
Microcomputers have from 4k to 64k storage location and are capable of handling small, single-business application such as sales analysis, inventory, billing and payroll.
HARDWARE & SOFTWARE The term hardware and software refers to the tangible & Intangible
aspects of computers. The physical parts of the computers are termed as “Hardware”. The instructions necessary to make the physical parts perform are
called “Software”.
HARDWARE Computer hardware refers to the actual, tangible physical parts of
the computers, it can be studied according to its functions it
performs such as :
Input Device Output Device Storage Device & The Central Processing Unit
INPUT DEVICE This device is responsible for entering data and commands into the
computer.
As computers developed, other forms of data storage to necessitating
the input devices such as magnetic tape readers.
As technology improved better & easier to use input devices such as the keyboard, mouse and scanner bar code readers etc
Today, sophisticated input devices like digital cameras and webcams have become available even to home computer users.
OUTPUT DEVICE This device are capable of outputting the processed information.
The need to produce output in more readable form saw the development of printers, which could be in words diagrams & pictures.
The need for immediate output which need not be preserved, as well as need to be able to monitor the processing led to the development of the VDU (Visual Display Unit)
Monitors of toady are capable of showing high resolution photographs & paintings.
STORAGE DEVICE & CENTRAL PROCESSING UNIT
When the data has to be stored for later inputs into another process, it can be output to media like magnetic disk tape CD ROMS etc such are called “Storage Device.”
Hard disk that can store larger amounts of data in random order, enabling faster access to a particular bit of data that might needed without having to read all data on the disk first.
Central processing unit (CPU) is the process the data into information according to the instructions (programs) given either by direct input (keyboard, mouse) or from external media such as magnetic disk.
CPU is further divided into (CU) control unit and (ALU) arithmetical and logical unit.
SOFTWARE Software is the intangible part of computer, it consists of a set of
instructions that tell the what to do.
A set of instruction is called a Program and A set of program is called
Package, and the sum total of the programs and packages used on
computer is called “Software.”
Some of the examples of application software are : Payroll Processing Software Inventory Control Software Accounting Software
PACKAGESA package, in computer terminology, is a set of program that can simply
be installed on a computer and used right away.
Software houses realised that most business needed the same basic set of
program with the slight modifications to suit their specific needs.
Some common packages are :
Word Processing packages Spreadsheet Packages
WORD PROCESSING PACKAGES AND SPREAD SHEET PACKAGES
WPP refers to the input, formatting storage and printing to text, it also
includes used to write letters, memos article report etc Most WPP provide features such as Page layout, automatic pagination,
columnar formatting and storage of documents as files in computer
system.
Spreadsheet packages offer quick & convenient ways to perform
calculations using larger number of variables. Spreadsheet packages also offers features like automatic generation of
graph & pie charts printing of individual parts of spreadsheet or entire
spreadsheet etc who need to work with numbers.
DATABASE MANAGEMENT SYSTEM Database management systems help the user to enter, store, retrieve,
format and print- cords related to individuals that form a part of a specific data base.
Eg : Package may be used to store employee code records.
Data package have evolved into sophisticated relational database management packages, where data from different tables can be accessed and combined to create cross- ferenced reports.
The data entered can be combined into reports for management use.
DESKTOP PUBLISHING Desktop publishing, referred to as DTP, is another powerful package
developed on PC’s.
Desktop publishing tools offer tools to make professional looking
documents and presentations integrating text and images.
The concept of WYSIWIG (What You See Is What You Get) makes it
easy for the user to lay his documents out exactly the way he wants it
printed.
This is a very useful tool in preparing reports, presentations, training
manuals, etc and such packages are widely used by professionals in
these fields.
COMPUTER SYSTEM CONFIGURATION
Configuration refers to the rating, capacity and functionally of critical
parts of computers.
Some of the important components in computers configuration are as
follow:
A. The Processor
B. The RAM or Random Access Memory
C. The Hard Disk
D. The Monitor or VDU (visual display unit)
A. THE PROCESSORB. THE RAM RANDOM ACCESS MEMORY
1. The is the brain of computer and most common processor are Intel Processors, the current rage being the Intel Pentium 4 processor, which of course will soon give way to another.
2. The faster computer will function, and the smoother will the graphics be, clock speed (measured in Megahertz or MHz) is another important factor in selection a processor.
1) RAM is another important factor in configuration of the computer & also refers to the working memory of the computer.
2) The maximum amount that can be stored in the temporary memory of the computer while performing calculations, and Moderns programs & packages especially use GUI (Graphic User Interface) are memory-hungry programs/packages need larger amount RAM function properly.
C. THE HARD DISK D. THE MONITOR OR VDU (VISUAL DISPLAY
UNIT) 1. Just like RAM, the larger the hard disk capacity, the better off one is
in the long run.
2. Hard disk capacity is now measured in Gigabytes or GB, where 1GB equals to 1000 megabytes.
1) While the size or type of monitors may not have direct bearing on the processing speed of the computer, it does play an important role in the presentation of data.
2) Computers are used to display graphics or images such as Drawings & photograph and has to be compatible with rest of system to provide smooth operation.
DATA PROCESSING Data processing refers to the collection, capture, storage & combination
of data into useable results.
In computer system, data is input & information is the output, the
conversation of data into useful information is called Processing.
Data: Data refers to individual elements which by themselves are
incapable of providing a basis for decision making.
Information: Information is the basis on which decision can be made
and information is produced by combining data & formatting the result
into a usable form.
TYPES OF DATA PROCESSING Data processing is essentially of 3 types:
I. Batch Processing
II. On-line Processing
III. On-line Real Time Processing
A. BATCH PRODUCTION Batch production refers to the collection of data different times within
a period & processing that data in the batch at specified intervals or at the end of the time period.
B. ON-LINE PRODUCTION The data is processed immediately upon the occurrence of the
transaction is called on-line processing. Most companies use a combination of Online and Batch processing,
depending on their requirements.
C. Online Real Time Processing Information required to be processed immediately, that result too have
to be produced at the end of the transaction is called online real time processing.
TRANSACTION PROCESSING I. Transaction Processing refers to the different kinds like cash
payments, reimbursement to employees, financial transaction etc
II. Transaction Processing is one of the most common forms of processing in the business organization
DISTRIBUTED PROCESSINGIII. This form of processing refers the setting up of smaller processing
units throughout the organization, which are linked through networking to each other through central computer called Server.
IV. Distributed processing also has its unique set of problems, which, may allow different departments to apply their own parameters o report formats, programs used validation exercises etc.
VALIDATION AND CONTROLS No matter how sophisticated a computer, it can be as accurate as the
data that fed in Garbage In Garbage Out or (GIGO) is basic concept that needs to be absorbed by every user, manager and system professionals.
Some of the Input Errors:
1. Transposition Error: In this type of error, two digits in a number may be ‘transposed’
2. Transcription Error: It refers to where a number or letter is misread by the operator.
3. Random Error: In this type of error, the number entered is completed erroneous.
CONTOLLING INPUT ERRORS Input errors can be controlled by several means, depending the nature
of data, this is called Validation. Validation checks can be built into the input program, so that common
errors are minimized or eliminated completed.
The second type of error that may in occur in system is a Processor error A processor error occurs when the output of one process is passed on
to another process as input. Processor controls are used to ensure that all of the relevant output is
indeed passed on to the next process. If the system accepts such erroneous data, validation checks have to be
put in to prevent input of such erroneous data.