Dear Students from the below content you can download amendment notes for INFORMATION TECHNOLOGY (PCC/IPCC). Hope you find it beneficial for your exams.Best of luck for the examination.

Dear students scroll down to the page and find attached pdf files..Dt. 18-01-2013

I Unit IMP Questions. Unit Test on - 04-12-2012

1)Write about different generations of computers

2)Write about Mainframe Computers.

3)Write about Mini Computer. 

4)Write about Micro Computer.

5)With reference to computers, explain briefly what is workstation?

Student this video will explain about Flow Charts.. Its worth to watch..

1. Introduction to Computers

Q.No.1. Write about different generations of computers (Or) Historical Development of computers. 

Introduction:

The modern computer, which we are using today, is not the invention of a single individual. It is the result of countless inventions, ideas and developments made by many people throughout the last several decades.

The history of automatic data processing begins with Charles Babbage’s attempt to build a mechanical calculator at Cambridge, England, in 1830.

By the end of 1930, punched cards were in wide use in many businesses.

In 1937, Howard Aiken, at Harvard, proposed to IBM that a machine could be constructed which would automatically sequence the operations and perform calculations. That was the origin for the development of automatic computers.

First Generation Computers: (1946 to 1959)

UNIVAC (Universal Automatic Computer) was the first general purpose electrical computer. ,, These computers employed vacuum tubes.

These computers were large in size and required air conditioning (as they produce huge heat). ,, The input and output units were punched cards.

The input and output devices were very slow when compared to the speed of CPU. ,, They were very expensive.

The medium of internal storage was magnetic drum.

Language used was Machine level language.

Processors speed used to be measured in milliseconds.

IBM-650 was the most popular first generation computer and was introduced in 1950 with magnetic drum memory and punched cards for input and output respectively.

It was intended for both business and scientific applications.

Second Generation Computers: (1959 to 1965)

These computers employed transistors and other similar devices.

Their circuits were smaller than vacuum tubes and generated less heat. Hence they required less power, were faster and more reliable.

There were two separate categories of second generation computers - for business & scientific applications. ,, IBM 1401 was the most popular second-generation computer

They employed magnetic tape as input/output media. Main medium of internal storage was magnetic core memory. Language used was Assembly language.

Processor speed started to be measured in microseconds.

Third Generation Computers: (1965 to 1970)

They employed integrated circuits, in which all the elements of an electronic circuit are integrated (=included) on a tiny silicon wafer.

They were much cheaper and more reliable than second-generation computers. ,, Their speed is high and can support variety of peripherals.

They are based on the principles of standardization and compatibility.

The secondary storage of a particular computer can be easily expanded. ,, They can be used for both scientific and business  applications.

They permit multi-programming, time-sharing, virtual memory and remote terminals. ,, They also support high level languages such as FORTRAN and COBOL.

Mainframes, Mini computers are also one of the developments in third generation computers. ,, Limited communication facilities were also available.

Processors speed started to be measured in nanoseconds.

Fourth Generation Computers:  (From 1970)

They appeared in 1970’s. They utilised still newer electronic technology and made the computer still smaller and faster than third generation computers.

Many new types of terminals were also developed at this time. One of the major inventions was the large scale Integrated Circuit (LSI). It is a small “chip” consisting of thousands of small electronic components, which function as a complete system. With this technology the entire CPU can be built onto a single chip of size less than 1/3 inch square. This technology helped to reduce cost and increase speed.

The speed of microprocessors, the size of main memory and hard disk increased tremendously. Many of the features of mainframe CPU’s were introduced in these computers. In 1995 the most popular CPU was Pentium.

These computers are being used in various areas like visualization, Parallel computing, virtual reality, Multimedia etc.

Object oriented languages were introduced such as C++, VB, etc. ,, Microcomputers and supercomputers are introduced at this time.

Fifth Generation Computers:

It is very difficult to define the fifth generation computers because it is still under development. ,, Introducing “Artificial Intelligence” to computers is the major development in this generation.

Artificial Intelligence is a software that tries to imitate human characters such as reasoning, communicating, seeing and hearing etc. This software can use its accumulated knowledge for decision making. In some cases, these systems can learn from past experiences and can modify its subsequent actions.

This artificial intelligence is being used in several areas such as:

- Natural languages,                                                             - Imitating human voice,

- Voice recognition,                                                             - Visual recognition,

- Translating from one language to another language,            - Robotics,

- Neural networks,                                                                - Expert systems.

At first all these applications seemed to be very simple. When programmers started working, they realised the difficulty.

It will take several years for the development of such systems. 

2. Write about different types of computers

Analog Computers: (N95)

They represent numbers by a physical quantity i.e. they assign numbers by physically measuring some physical property such as length of an object, angle created by two lines, voltage, temperature, pressure, etc. (Simply saying analog computers measure).

Analog computers get input through some measurement. The accuracy of analog

computers is directly related with the accuracy of its measurement.

Data such as voltage, resistance, temperature, pressure etc. are represented in a computer as a continuous unbroken flow of information.

These are very useful in engineering and scientific applications.

But they are less accurate and the storage capacity is also limited. Hence they are not suitable for business data processing.

Digital Computers:

Digital computers represent data as numbers. Counting on fingers is the simplest form of digital computer. Adding machines and pocket calculators are common examples of digital computers.

They accept input from various input devices, convert them into numbers and perform arithmetic or logical operations on such numbers.

It is also capable of storing data, performing logical operations, editing, deleting, printing the output etc.

The accuracy is also high. Hence suitable for business data processing applications. ,, Cost is comparatively higher than analog computers.

Programming is complex in nature.

Hybrid computers: Hybrid computers combine the best features of analog and digital computers. They have the speed of analog computers and the accuracy of digital computers. They are used in areas where data from analog devices is converted into digits & processed by computer.

For e.g. Analog devices measure patient’s vital signs like temperature, heart function etc. These are then converted into numbers and supplied to digital components of the system. Now digital components of the computer will process such data.

On the basis of function

Special Purpose Computers:

These computers are designed to perform a special task [restricted class of problems]. Therefore, instructions are inbuilt into the computer circuitry by the manufacturers.

Thus a given task is performed quickly and efficiently.

They are generally used for applications such as air line reservation system or for solving navigational problems etc.

However, these computers are not versatile i.e. it cannot be used for any other purpose. General Purpose Computers:

They can be used for many purposes such as business, scientific, educational, social and other applications. Everything depends on the program it uses.

At the same time, they can store different programme instructions.

Wide variety of jobs can be handled by these computers i.e. it is completely versatile. ,, On the other hand old programmes can be amended or dropped.

Scientific & Business Computers:

Scientific problems involve huge amount of complex computations but involves small amount of input and output. Since input / output volume is low, the speed of input / output peripherals is not so important. But processing speed is very important because some problems may take several man months or even years for computation.

Reverse is the case with business applications. Volume of input / output is very high. Arithmetic computations are neither voluminous nor complex. Therefore they need fast peripheral devices.

Another difference is the storage requirement. Scientific systems have lengthy programmes but handle very small amount of input data. Therefore storage requirements are less when compared to business applications.

On the basis of capacity

Super computer,           (1980)

Main Frames,                 (1964)

Mini Computer and          (1968)

Micro computer.             (1974)

3. Write about Super Computers.

Meaning:

Super Computers are the largest and fastest computers available. Generally, they are not used for commercial data processing.

Super Computers have huge amount of memory and high processing speed. ,, They can process up to one billion instructions per second.

Super Computers can process 64 bits or more at a time. Their processing speed ranges from 10,000 million instructions per second (MIPS) to 1.2 billion instructions per second.

They can support up to 10,000 terminals at a time.

Super Computers can recover automatically from failures (fault tolerance).

Conventional computers have single processor which can process one instruction at a time. But super computers have multiple processors (or CPUs) that process multiple instructions at a time. This is called parallel processing.

In olden days high clock rate was considered as the main difference between ordinary computers and super computers. Now the distinguishing feature of super computers is their high degree or parallelism i.e. super­computers consist of several processors, which can process simultaneously.

Milestones: The first super computer was the ILLIAC IV made by Burroughs. Other suppliers of super computers are CRAY, CDAC [PARAM 2000 FROM INDIA], Fujitsu, Intel Corporation, Thinking Machine Corporation, Hitachi, IBM and Sun Microsystems, etc.

Where they are used?

These computers are used in specialized areas such as Defence, aircraft design, computer generated movies, weather research etc.

In medical field, super computers are used to study the structure of viruses, impact of various drugs on human beings etc.

Designing an aircraft involves simulating (=to create) and analyzing the airflow around the aircraft. This again requires a super computer.

4.Write about Mainframe Computers.

Mainframes are less powerful and cheaper than Super computers. However, they are big general-purpose computers and they can handle all kind of scientific and business applications.

Mainframes can process several million instructions per second.

Mainframes can be used for a variety of applications. A typical application of these computers is airline reservation or railway reservation system.

It can support many powerful devices. (E.g. a main frame can support more than 1,000 remote terminals.)

Mainframes have large secondary storage capacity. Variety of peripheral devices like

magnetic tape drives, hard disks, visual display units, plotters, printers and telecommunication devices can be connected to main-frame computers

They have high-speed cache memory which helps to process data at a faster rate than mini or microcomputers.

They also offer the facility of multiprogramming.

Prices of Mainframe computer ranges from 1 crore to 5 crores depending upon the configuration.

Major suppliers of mainframe computers are IBM, HP, Sun Microsystems, Honey well, Burroughs, NCR, CDAC and Sperry etc.

Large mainframes can have hundreds of MBs of main memory and hundreds of GBs of secondary storage. 

Note: Super computers Vs. Mainframe computers. (M00-5M, RTP)

5. Write about Mini Computer. (N93)

It is a relatively fast, small and inexpensive computer.

The input/output capabilities are some what limited.

Data processing is similar to that of mainframe but on a small scale. The cost of minis is low.

Usually data is input by means of a keyboard. As the name implies, a minicomputer is small, compared to a mainframe. It is also called as scaled-down mainframe. The processor and the peripherals are physically smaller.

Minicomputers cost from Rs.5 lacs to Rs.50 lacs. The most popular minicomputers or minis are Data General Nova, IBM series/1.

These computers can support multiple number of users.

Programming languages include BASIC, PASCAL, COBOL, C and FORTRAN.

Minicomputer systems can support most of the input/output (I/O) devices and secondary storage devices that large mainframe systems can handle.

They are also used to develop distributed data processing systems. Instead of having large mainframe computer, a company may install mini-computer at each remote location and connect them to each other through telecommunications.

6. Write about Micro Computer.

Micro Computer:

A microcomputer is a full-fledged computer system that uses a microprocessor as its CPU. Microprocessor is a small chip which may vary from fingernail size to postage-stamp size.

Microcomputers were first available in 1970s. The first microcomputer designed for personal use was ‘Altair’.

PC Vs. Micro Computer:

The term PC has a more specific meaning. In 1981, IBM named its first microcomputer as IBM PC. Within few years, many companies copied the IBM design, which can function like IBM PC’s and are called IBM clones or IBM compatible computers. Thus the term PC includes IBM PC and its compatibles.

On the other hand Apple Macintosh  computer is neither an IBM PC nor its compatible. It belongs to another family of microcomputers made by Apple computers.

Internal memory 256 MB expandable to 512 MB and more; Backing storage-cassette, floppy disc, microfloppy discs, micro-drive, silicon disc or hard disc, CD-ROMS, DVDs, pen drives etc.;

Keyboard and screen (input and output);

Interface (for the connection of peripherals);

Bus (communication and control channels);

Printer and/or plotter (multicolour text and graphics);

Pulse generator (clock);

Light pens, mouse, paddles/joysticks, Multimedia (graphics and games);

Software (programs)

Usage: Microcomputers are useful even to the smallest businesses. However their primary market is the personal home computer market. 

7. With reference to computers, explain briefly what is workstation? [IMP] 

Meaning:

Between minicomputer and microcomputers - in terms of processing power – there is a class of computers known as WORKSTATIONS.

A workstation looks like a personal computer and is typically used by one person. Workstations are still more powerful than PC. There are 2 major differences between a workstation and a PC.

Internally, workstations are constructed differently than microcomputers. They are based on different architecture of CPU called Reduced Instruction Set Computing (RISC), which results in faster processing of instructions.

On the other hand most microcomputers can run any of the four major operating systems - DOS, Unix, OS/2 and Microsoft Windows NT. But workstations run on Unix operating system.

A disk less workstation does not have floppy disk drive. Data storage is provided by centralized hard disc. This provides control over data storage because it reduces the possibilities of data theft.

Manufacturers: The biggest manufacturer of workstations is Sun Microsystems. Other manufacturers include IBM, DEC, Hewlett Packard, Silicon Graphics, DELL etc.

Conclusion: Many people use the term workstation to refer to any computer or terminal that is connected to another computer. But this is an outdated term. These days, a workstation is powerful RISC based computer and is generally used by scientists and engineers.

Note: Micro computer Vs. Workstation. (N03-4M)

IMP Notes

Central Processing Unit          : It is the heart of the computer that makes comparisons,                                       performs      calculations, reads, interprets and controls the execution of the instructions.

 BIOS                   : It stands for Basic Input Output System. It is a small chip on the mother                                board that Loads the      hardware    settings required to load various devices like                                 key     boards, monitors, or disk drives.

Intelligent Terminal       :        It is a terminal which has an in-built processing capability. It                     is user         programmable and contains not        only a storage area but also a micro-                                                processor.

Seek Time   : This is a time required to position a movable read-write head over the                                                               recording track     to be used.

File Pointers         : They establish linkage between records and are a basic part of the file                                                                         Organization of all the database models except the relational model.

Light Pen             It is a pointing device which can be used to select an option by simply                                                                 pointing at it,        or drawing figures directly on the screen.

Ethernet      :        It is a very common network protocol. It uses the linear-bus topology and is                                                 Inexpensive and    simple.

Output Devices               : They are instruments of communication between people and                                                                                                 machines. They are used to      record the     results obtained by the                                                                                          computer and present them to the outside world.

PROM                  :        It stands for Programmable Read Only Memory. It is a non-volatile memory                                    which          allows the user to program the chip with a PROM write.

Dumb Terminals  : They are the terminals which cannot do processing on their own and                          Serve only as input /       output         mechanisms that link users with the central                              CPU in a large system    computing. 

Rotational Time   : This is the rotational delay also termed latency, to move the storage                                               Medium underneath the read-write head.

Buffering              : It enables the processor to execute another introduction while input or                                                     output is taking place     rather          than being idle while transfer is being completed.

Query Language           : It is a set of commands for creating, updating and accessing data                                from a         database. It           allows programmers, managers and other users to ask adhoc                             questions of the database interactively         without the aid of       programmers.

Half Duplex                   : It is a transmission mode under which data can be transmitted back                              and forth between two stations, but   data can only go in one of the two directions                       at any given point.

Protocols    :        They are software that performs a variety of actions necessary for data                                            Transmission between computers. They are a set of rules for inter-computers. They                       are a set of rules for inter-computer communication that have been agreed upon                                       and implemented by many vendors, users and standard bodies.

Data  :        Data can be defined as any fact, observation, assumption or occurrence. They are                              Useful         knowledge   or information of value to an individual or business. They are                         factual material    used as a basis for          discussion, decision, calculation, or                                                                measurement. Data are compiled to             form reports, figures, or documents etc.

Information                   : Information is organised or classified data so that it has some surprise                                       value to the receiver.       For example, the daily production figures are raw data for                             the managing director to whom they have little     value as such.

Data Processing             : is the restructuring or reordering of data by people or machines, to                                       Increase their usefulness and value for some particular purpose.

EDP:          offers better method of data processing at a low cost per unit processing as it relies                              on the computer    and principles of electronics for processing data. Data to be                                   processed by this method can be recorded on        one of the several media for input.

Arithmetic and logic unit (ALU)       : performs mathematical calculations, compares                                                  numeric and non- numeric       values and makes decisions. The data flows between                           this unit and the storage unit during processing.

Secondary Storage                  : Because the primary storage capacity of most computers is                                          limited, it is both expensive      and not always possible to hold a large volume of                       data and     instructions in the primary storage. Hence it         becomes necessary to have                     secondary or auxiliary storage for holding data and programs not currently in use

 ASCII System               : the American Standard Code for Information Interchange, called the                              ASCII Code uses the right most seven bits of the 8-bit byte to represent numbers,                        letters of the alphabet, and special characters. This provides for the representation                          of a maximum of 128     individuals characters.

Flash memory      : It is a form of static RAM (SRAM) chips, store data much like those used                    In the computer’s primary storage. However, the data stays recorded even when                              the power is turned off flash memory is non-volatile. Since flash memory devices                            have no moving parts,    and are therefore very fast, they may eventually replace                           slower, mechanical hard disk drives.

Voice Recognition                   : Translating voice to text is a capability known as voice recognition                     (or speech recognition). Voice recognition software takes the smallest individual                                  sounds        in a language,      called phonemes, and     translates them into text or                                                    commands.

FAT  : It is a log that records the location of each file and the status of each sector. When                          a file is written to a         disk, the operating system checks the FAT for an open area,                              stores          the file, and then identifies the file      and its location in the FAT.

Data Integrity       : refers to the correctness of the data into the database. The results from                         the fact that           updates       to data stored in one file may be made to the other files                                containing the same data.

Data Dictionary             : Data dictionary is a centralized depository of information, in a                                             computerized form, about        the data in   the database. The data dictionary contains                            the scheme and description of the database.

Artificial intelligence (AI)        : is software that tries to emulate aspects of human behavior,                                Such as reasoning,         communicating, seeing, and hearing. AI software can use its                       Accumulated knowledge to reason and, in some instances, learn from                                                                              experience and thereby modify its subsequent reasoning.

Simplex                : A simplex communication mode permits data to flow in only one direction. A                              Terminal connected to such a line is either a send-only or a receive only device.

Multiplexer : This device enables several devices to share one communication line. The                                       Multiplexer scans each device to      collect         and transmit data on a single line to the             CPU.

Clock Speed         : The clock speed is the speed at which the processor executes instructions.           Clock speed is       measured in megahertz (MHz)—which is a million cycles per second.

Integrated Circuit : The very thin silicon chip contains a number of small storage cells                     that can hold data. Instead of being made up of a series of discrete components,                              these units are constructed as integrated     circuits, meaning that a number of                                 transistors are       integrated or combined together on a thin silicon wafer           to form a               complete set of      circuits

Interleaving Techniques                   : A technique large computer systems often combine (interleave)            the processing       work  of multiple   simultaneous users or applications in a manner                 that achieves the highest possible       resource efficiency. Among the interleaving                                                 techniques commonly used are multiprogramming, foreground/background processing,            multi-tasking, virtual memory, and multi-          processing.

Synchronous Transmission              : This transmission, bits are transmitted at fixed rate. The                    Transmitter and receiver both use the same clock signals for synchronization.

Bridges       :        The main task of a bridge computer is to receive and pass data from one LAN                                        to another. In order        to       transmit       this data successfully, the bridge magnifies the                                    data Transmission signal.

URL  :                  is the standard way to give the address of any resources on the internet that is                    part of the World Wide Web.

Interpreter   : It refers to a language translator that converts source program written in                    high level language to    machine code        and executes it immediately statement by                        statement.

Stored program concept          : Computers can perform variety of mathematical calculations                    without error. They         can sort data, merge lists, search files, make logical decisions                        and comparisons. However, computer         is devoid      of any           original thinking. It is                                  provided with a set of instructions. These instructions are     stored in      primary                                             memory and executed           under          the command of the control unit of CPU. This is                                known as stored          program      concept.

Toggle                           : It is a switch or control code that turns an event on or off by repeated                                                           action or use. It also means to turn something on or off by repeating the same                                      action.

Object program    : It refers to a program expressed in a machine language, which can be               directly executed by         a        particular computer. A compiler takes source program as an               input and produces the object code/program.

Router                  : It is a special purpose computer along with software that handles the                                             connection between two or       more networks. Routers spend all their time looking at the                   destination addresses of the packets   passing through              them and deciding which                            route to send them on.

FTP            : It stands for File Transfer Protocol. It is used to upload the files from client                                             computer to remote Web- server. ( it is a very common method of moving data                                      between tow internets sites. 

DBMS        : It is a complex system software package which allows the user to create and                maintain the database files. Data      security is defined with the help of DBMS using              passwords and access rights. DBMS allows          only authorized users to access the                        data according to their access privileges.

Duplex Printing             :        Printing on both sides of a paper at the same time is called Duplex                  Printing.

Gateways              :        It is used to connect two dissimilar networks but do not possess network                    management facilities.    They are used to connect LANs of different topologies e.g. Bus             and Ring Network.

Asymmetric Crypto System      :        In this cryptography technique, both the parties use                         different keys for encryption/decryption. The key known to the sender is called Private                  Key and receiver key is called Public key. A person using asymmetric crypto system                   publishes his Public key so that it can be known to all the persons who want to                          confirm the identity of the sender.

Subroutine:                   It is a subset of instructions that appears over and again in the                                     program or finds applications in       several programs.  It is economical to write it                            once and for all.  This saves     time for       writing and debugging and can be used                                       repeatedly in the same program.

Parity bit                        :  It is an additional redundant bit that is used to provide a check on                              the integrity of a data representation.          It helps in    detecting any errors that may               occur while transmitting a binary data.

Accumulator        :        it refers to a storage area in memory used to accumulate totals of units                                                                    or of amount being computed.

Data Independence        :        database system keeps description of data separate from                                                                    applications that use the data. Thus, changes in the data definition can occur                                              without necessarily requirement changes in every application programs that used                             the data. The result could be substantial reduction in program maintenance cost

Client                   :        it is software that is used to connect & obtain data from a server software                         program on another computer, often across a great distance. Each client program is            designed to work with one or more specific kinds of server programs. A web browser                   is a specific kind of client.

PPP            :        ( point to point protocol )         it is most well known protocol that allows a                                                 computer to use a regular telephone line & a modem to make  TCP / IP internet                               connection and thus be really on the internet.

Access Time          :        it refers to the time interval between the instant when a computer or                                       control unit calls for transfer of data to or from storage device to or from a storage                         device to the instant when its operation is completed. Thus, access time is the                                          waiting                 time and transfer time.

HTML                  :        this coding languages is used to created hypertext document for use on the                                  web. It allows the creator of the web page to specify how text will be displayed                                 and how to link it to other web pages, files & internet services.

CMOS                  :        personal computer used the CMOS memory to store the date, time & system                             setup parameters. These parameters are loaded every time the computer is started.                        It is powered by lithium ion battery.  

Object oriented database.                  :        it provides a repository of reusable objects that only need to                  be created once. This allows new application to be put together by appropriately                                     arranging the objects stored in the OODB.

Structured query language ( SQL)   : it refers to a set of commands for creating updating               and accessing data from a data base. It also aids the manager to make ad hoc queries           from the database.

Drag : it refers to the activity of moving something around the computer monitor with            the help of the mouse. Dragging involves holding down one of the mouse buttons                         while the user moves it.

Bi-directional printing   : under bi-directional printing, a printer types the first line from                  left to right and the second lien from right  to left and so on through out the page.                  This speeds up the printing sequences.

Formatting :        the process of creating tracks and sectors on the storage media is called                        formatting. By this process, each location of the storage media is assigned a physical                address for reading / writing the data.

Internet service provider ( ISP)                   :        an institution that provides access to the internet                           subscriber on a charge basis is referred to as internet service provider. For example, in              India VSNL is one of the internet service providers.

Two uses or reasons

Use of Diagnostic programs             :        These are referred as debugging routines or aids. A                                       Diagnostic routine is a program        that is invoked to provide information or                          assistance to a programmer on those occasions when his program      fails to operate               correctly.

 Use of Parallel Port: Parallel ports are used to connect external input/output devices like

                   scanners or printers. Parallel ports facilitate the parallel transmission of data, usually                  one byte at a time. Parallel ports use 25 pin Rs. 232C.

Use of interactive processing:

·        Here there is a continuous interaction between user and the machine, therefore it is

·        Possible to provide the intermediate results to the user.

·        The cost of this system is higher, as interactive devices need to be provided.

 Preference of Network model over hierarchical model:

·        Network model permits many to one and many to many which is not supported by

·        hierarchical model        

·        Network model is relatively flexible than hierarchical model.

Bootstrap loader program:

·                    These are programs stored in ROM to bring the operating system from secondary

·                    Storage to primary storage when the computer is switched on.

·                    This makes the computer system operational and provides responses to user commands.

Need for Master File:

·                    Relatively permanent.

·                    Master files of past become historical files.

·                    Historical Files are used for comparison purposes e.g., sales analysis.

·                    Master file is updated using transaction file.

          Examples: Payroll Master File, Inventory Master File, Student Master File, etc.

Use of Cache Memory:

                              The Cache memory acts as a temporary memory and boosts    processing power                                      significantly. The cache that comes with the processor is called level one (L1) cache.                          This cache runs at the processor        clock speeds, and therefore, is very fast. The                                               L1 cache is divided into two sections one for data, and        other for instructions.

 Preference of relational database model with comparison to hierarchical          database model:

                              A relational database is structured into a series of two dimensional tables. It allows                            flexibility in conducting database     queries and creating reports. The link between                             data elements need not to be made    explicit        at       the time the database is                                             created. It is more flexible and provides managers with rich opportunity      for ad-                                      hoc reports and queries. In case of           hierarchical database, hierarchy of records                                       must be           determined and     implemented before a search can be conducted.

Use of File pointers:

                     File pointers establish linkage between records and are a basic part of the file                                          organization of all the              database models   except the relational model. A pointer is                   the address of another related record that is         pointed to? The pointer directs the                                        computer to that related record. It is placed in the last field of a         record, if               more           than one pointer is used, then in the last fields.

Need for a repeater in a network:

                    Repeaters are used to amplify the signal between the sending and receiving           stations.                Their purpose is to         keep the       intensity of the signal at the required level. When                          signal travels long distance, its strength becomes feeble due to cross talk and other                       electromagnetic interferences. Hence repeaters are used to           maintain the         intensity                at the original level.

Expansion slot

          1. To give built –in devices such as hard disks and diskette drives access     to the                                                  computer’s bus via         controller cards.

          2. To provide I/O (input/output) ports on the back of the computer for external devices           such as        monitors,     external modems, printers, and the mouse (for                                            computers that do not have a built-in mouse         port).

Graph plotter

          1. Graph plotter is a device capable of tracing out graphs, designs and maps into paper                    and even into        plastic or metal plates. This device is suitable for routine graph                                       plotting and also for fashion    designs.

          2. Business generally uses plotters to present an analysis in visual terms (bar charts,                         Graphs, diagrams)                   etc. as well as                 for engineering drawings.

Worm disk

          1. These are used by end user companies to store their own proprietary information.

          2. WORM disks are used in information systems that require the merging of text and               Images that do not change for a        period                   of time.

Virtual memory 

          1. Virtual memory systems, sometimes called virtual storage systems, extend primary                memory by treating disk storage as a logical extension of RAM.

          2. The virtual memory feature allows him to consider unlimited memory size to the                           Programmer, though not in physical term.

Utility programs

          1. Sorting and editing the output data.

          2. Converting data from one recording medium to another, viz., floppy disk to hard                         disc, tape to printer,       etc.

Expert systems

          1. They can outperform a single expert because their knowledge is representative of                                    numerous experts. They are faster and more consistent and do not get distracted,                      Overworked, or stressed out.

          2. They produce better-quality and more consistent decisions. Expert systems assist                           Users in identifying         potential decision making problems, which increases the                                       probability that sound decisions, will be      made.

NIC

          1. Network interface cards (NIC) provide the connection for network cabling to servers           and workstations.

          2. An NIC has additional memory for buffering incoming and outgoing data packets,                      thus improving the network      throughput.

Data center

           1. A database monitoring is done by the database agent, which enables the high                                                Availability of the database      through comprehensive automated management.

          2. It is used to monitor the website performance, availability, integrity and the                                            Responsiveness from a site visitor’s prospective.

Decision Table

          1. A decision table provides a framework for a complete and accurate statement of                                     Processing or decision             logic. It forces a discipline on the programmer to think                                    through all possible conditions.

          2. A decision table is compact and easily understood making it very effective for                                         Communication between                    analysts or                      programmers and non-technical users.                    Better Documentation is provided by it.

Wireless Networks

          1. One is the portable office. People on the road may often want to use their portable                       electronic    equipment to         send and receive             telephone calls faes and electronic                                 mail, read   remote files, logic           on remote    machines               and can so on and                             do this from anywhere on land, sea or air.

          2. Wireless networks are of great value to fleets of trucks, taxis, buses and repair-                             persons for keeping in              touch                    with             home. Another use is for rescue                                           workers at disaster sites (fires, floods, earthquakes,                   etc.)   Where the             telephone    system has been destroyed, computers there can find messages, keep records and      so on.

HTTP         :        HTTP is used to process information to and from the Web server; pages. Using                             HTTP,                  HTML provides    the capability to specify graphic files to be displayed.

Teleconferences  :          His use of teleconferences is that they allow collaboration by people not                    in the same Location.    For example, one could hold a teleconference with                                                         participants in different Countries. This eliminates                   the need for everyone to travel                 to the same location.

Use of Macro: Macro is a small program used for carrying out a pre-recorded series of                            steps by giving few keyboard shortcuts. It automates the tasks, and carries out                                   those pre-defined steps automatically once it is triggered.

Use of BIOS         : BIOS stands for Basic Input Output System. It is a small chip on the                   motherboard that loads the hardware        settings required to load various devices                                   like keyboard, monitor or disk drives. Most new PCs      come with flash           BIOS                    –                           these BIOS can be software upgraded to support new devices.

Use of Web Browser: It is a client program (software) that is used to look at various                                  kinds of Internet resources. Mosaic, Netscape Navigator and Internet Explorer are                              some of the commonly used web                  Browsers.

Use of Repeaters: These are devices that solve the snag of signal degradation as data is                            transmitted along various cables. Repeater           boosts or amplifies the signal before                             passing it through to the next section of                 cable.

Use of Firewall in the system: Firewalls are systems that control the flow of traffic                                     between the Internet and          organisation’s                Local Area Network and Systems.                                   Firewalls are packaged as turnkey hardware and           software packages and are setup            to enforce specific security policies that are desired. Firewall is an           effective means of            protecting the internal resources from                   unwanted intrusion.

Need for Macro in Spreadsheet: Macro is a small programme that carries out predefined                and prerecorded   series of steps by giving a few keyboard shortcuts. We can say that              Macro is like a recorded movie, which         can be run any number of        times. Macro is                              just a way of doing work in a series of steps, which it carries out            automatically                           once it is triggered.         Hence, the need of Macro is to automate the tasks, thus saving                   lot of precious time.

Use of USB port: USB stands for Universal Serial Bus. These ports provide the user                         with higher data   transfer       speeds for different USB devices like keyboard,                                            mouse, scanners or digital camera.

Use of Router: Router is a special purpose computer or software package that handles the               connection between two or more      networks. Routers spend all their time looking                         at the destination addresses of the packets   passing through them and                                                                 deciding on which route the packets should be sent.

Use of Multiplexer: This is a device that enables several devices to share one                                             communication line. It scans    each            device to               collect data for transmission on a single communication line. It is often used with a           complementary demultiplexer                  on the receiving end. As such it restricts the need of multiple              communication     lines.

Use of Serial Interface:  A serial interface is used to connect a printer to the input                            device, either a      computer or word                              processor.  It allows the printer to accept                   transmission of data, which is sent     serially, or one character at a time.

Use of spooling software:  The purpose of spooling software is to compensate for the                       speed difference    between the computer and its peripheral devices. These programs               take the results of computer program and move them from primary memory to                         disk.  The area on the disk where program results          are sent is commonly called                         the output spooling area. Thus, the output device can be left to interact primarily                    with the disk unit, not the C.P.U.  It can be used on the input side also.

Need of reference file – These files contain keys of records in other files.  In order to retrieve             a record      from a file, the reference file is first searched to find out in which file a                         record can be located.

Video ram            :        VRAM is used to accelerate the display of graphics on the screen. It does            this by using two ports one connected to the CPU & other to the screen. Data flows                    in one ports and get out of he other very smoothly.

FAT            :        file allocation table is a logo that records the location of each file and the status                    of each sector. When a file is written to a disk, the operation system checks the FAT            for an open area stores the file and then identifies the file and its location in the FAT.           The fat solves a common filling problem. For storing larger files, free space at different                location is used and pointers are added in the FAT.

Use of file pointer.         :        file pointer establish linkage between records and a basic part of the               file organization of all the database models except the relational model. A pointer is                    the address of another related record that is pointed to the pointer directs the                                             computer to that related record. It is placed in the field of a record, if more than one                pointer is used , then in the last fields.

Need Of Hub In A Network.             :        a hub is a hardware device that provides a common                              wiring point in a LAN. Each node is connected to the hub by means of simple twisted                  pair wires. The hub then provide a connection over a higher speed link to other                              LANs , the company’s WAN or the internet.    

Use of parallel ports       : parallel port are used to connect external input / output devices                                   like scanners or printers. Parallel ports facilitate the parallel transmission of data,                     usually one byte at a time. Parallel ports use 25 pin RS 232C.

Use of gateway in computer network.         : gateways are usually used to link LANs of                                       different topologies , e.g. Ethernet and token ring for enabling the exchange of data.                     They do not possess the management facilities of routers but like routers they can                       translate data from one protocol to another.

Use of drivers       :        drivers are small programs that translate the program’s generic                                              instructions into instructions for a specific piece of hardware. When a new hardware                is introduced the programmer of an operation systems just writes a driver for it.                              Operating systems has a library of device drivers, one for each specific hardware item.

Use of dynamic processing      :        this technique is used for swapping jobs in and out of                                 computer memory according to their priorities and the number of time slices                                                 allocated to each task. It helps in increasing the processing speed of various task.

Deference

[1]Analog computers : process data input in a continuous form. Data such as voltage,                                      Resistance or        temperature          and pressure are represented in the computer as a                 continuous, unbroken flow of   information. The   analog        computer offers low cost and                   ease in programming. The main disadvantage of          an analog        computer is its                                             accuracy     factor, and the limited storage capacity. Hence it is not suitable for                                                processing business           data.

Digital computers on the other hand, count and accept letters or numbers through      various           Input devices        that convert the data into electric pulses, and performs arithmetic           operations on numbers in discrete     form. In       addition to performing   arithmetic operations, they are also capable of (1) storing data for          processing, (2)      performing logical         operations, (3) editing or deleting the input data and (4)         printing      out     the result           of its processed routine at high speed.                  One of the main    advantages in the use of     digital         computers is that any      desired level of accuracy can   be achieved by considering as many places of decimal as is necessary and      hence are    most suitable for business applications. The main disadvantage      of digital     computers is          their high           cost and the complexity in programming.

[2] Mini computer performs data processing activities in the same way as the micro                computer but on a          larger          scale. Originally minicomputers were developed for process                  control and system monitoring etc.   They were complicated                    to program and        had    minimal input/output capabilities as they were mainly   concerned           with   “number crunching”              rather than handling large amounts of data relating to       business      transactions.         However, they are now fully    developed, powerful           computers with a wide range of       peripherals to perform    a        wide range of data           processing and computing                 activities. Minicomputer systems can be equipped           with most    of the input/output (I/O) devices and secondary              storage devices           that    the large mainframe       systems can handle, such as terminals and rigid disks. They are     also                      making        possible the           installation of       distributed data           processing systems.

Microcomputers: A microcomputer is a full-fledged computer system that uses a           Microprocessor as its     CPU;          these are also                 called personal computer systems. A    microcomputer often called a micro is a      small computer     consisting of a processor    on a single silicon chip which is mounted on a circuit board   with other    chips            containing the computer’s internal memory in the form of read-only-memory       (ROM)           and    random-      access-        memory (RAM). It has a keyboard for the entry             of data   and    instructions and a screen for    display        purposes. It           has interface for the           connection of peripherals in the                 form of mouse, plotters, printers,      cassette units,           disk    drives          and light pens etc. IBM PC, APPLE II, TENDY TRS-80 are              some of       the popular           microcomputers.   Microcomputer systems are used by even the smallest of       business.

[3] Data Bus is an electrical path that connects the CPU, memory, and the other          hardware           Devices on the       motherboard. Actually, the bus is a group of parallel    wires. The number of wires in the bus affects the        speed at       which data can travel     between hardware components, just as the number of lanes on a          highway      affects how long it takes people to get to their destinations. Because each wire can transfer      one bit         at a           time, an eight-       wire bus can move eight bits at a time, which is a full byte. A 16-      bit bus    can    transfer       two bytes, and a 32-       bit bus can transfer four bytes at a time.

Address Bus: The address bus is a set of wires similar to the data bus that connects the           CPU and RAM     and    carries the memory addresses. (Remember, each byte in RAM is           Associated with a number, which       is the memory address)? The reason the address bus           is important is that the number of wires in it         determines   the     maximum number of           memory addresses. For example, recall that one byte of data is         enough to    represent           256    different values. If the address bus could carry only eight bits at a time, the           CPU could address only 256 bytes   of RAM.

[4]     Random-Access-Memory (RAM): The memory system constructed with metal-oxide           semi conductor     storage        elements that can be changed is called a random access           memory (RAM). The purpose of RAM is      to hold        programs and data while they are           in      use. It is called random access memory since access time         in RAM       is           independents of the address of the word, that is, each storage location (address) inside the           memory is    as      easy to reach as any other location and takes the same amount         of time. RAMs can be         further divided      according to the way in which the data is    stored, into dynamic RAMs and static RAMs.

Read-Only-Memory (ROM): It is used for micro programs not available to normal           Programmers. The term read- only means that the storage cannot be altered by regular program instructions. The information is    stored          permanently in such       memory           during manufacture. The information from the memory may be read out    but     fresh           information cannot be written into it. The micro programs in read-only-     memory may           be      used for a    variety of purposes, but a common use is to hold a set   of instructions           that are needed     frequently, for       executing small, extremely basic         operations, which          are not otherwise available in the      computer circuitry.         One set of          instructions found in       ROM is called the ROM-BIOS which stand for Read-     only           Memory       Basic           Input Output services. Three types of ROM are PROM, EPROM and   EEPROM.

Cache memory refers to internal memory on the processor. It is a temporary                                                       memory and is used to    boosts the processing power of the computer significantly.

                             There are two types of cache memory. The cache that comes with the processor is           called Level One   (L1)   cache. This cache runs at the processor’s clock speed, and   therefore is very fast. The cache is      divided into 2        sections – one for data, the other for instructions. Generally, more the L1 cache, faster the         processor.   Additionally, PCs   also include a much slower secondary, or Level Two (L2) cache. This cache       resides on      the motherboard and delivers slower performance when compared with the L1 cache.

[5]     Magnetic Ink Character Recognition (MICR): MICR employs a system of printed           Characters which are     easily           decipherable by human beings as well as a machine           reader. There is used special printing font to       represent characters. In this font, each           character is basically composed of vertical bars the       characters are       printed in special         ink, which contains a magnetizable material. When a character is    subsequently read   it        is passed beneath a reading head and big and small gaps send in different types of           impulses represented by 1 bit and 0 bit respectively. This method is primarily used in           banking       industry, and most cheques are now processed under the MICR approach.

Optical Character Reading (OCR): OCR also employs a set of printing characters with           Standard font       that can       be read by both human and machine readers. The machine           reading is done by light scanning     techniques in         which each character is illuminated by a light source and the reflected image of the     character is           analysed in           terms of the          light-dark pattern produced. Key-board devices are used to give      the required print       quality. OCR        has the potential of reading even handwritten documents straightway.

          Optical character readers can read upper and lower case letters, numerics and certain           special characters           from handwritten, typed and printed paper documents. The           specific        characters that can be read and        whether the characters must be handwritten, typed          or printed depend upon the type of OCR being used. Large     volume billing         applications (e.g. the bills of utility companies, credit-card organisations, and           magazine    subscription outfits) increasingly are being adapted to   OCR methods. The customer     paying         the bill returns      the bill, which has OCR data   (e.g. customer number and    amount of the bill) recorded on         it, along-with        payment.

[6]     Impact  Printers: Impact printers can be described as printers which utilize some form of           Striking      device to      transfer ink from an inked ribbon onto the paper being printed to           form images or characters.       The    characters   printed are formed by one of two           methods: (I) they are either distinct, whole alphanumeric       images produced by a           process known as full character or formed character printer or,        (ii) they are formed           by a dot matrix     method which arranges a series of dots to assume the shape of           each character being     printed.

Non-impact printers: A non-impact printer forms characters by chemical or electronic

          Means. Three types of non-impact printers are these are thermal printers, ink-jet           printers and laser printers.      They are fast in operation, printing a page, or even more           in a second but currently they are too          expensive to          be widely used. The laser printer         produces very high quality prints from a wide selection of character fonts.

[7]Compilers: A compiler translates the entire program into machine language before the

          Program is executed. Compilers are most commonly used to translate high-level           languages such as          COBOL, FORTRAN, and Pascal. Compilers typically result in           programs that can be executed much more          swiftly than those handled by           interpreters.

Interpreters: Whereas compilers translate programs into machine language all at once

          Before programs are run, interpreters translate programs a line at a time as they are           being run. With an         interpreter, each statement is translated into machine language           just before it is executed. No object   module or   storable load module is ever           produced.    Although interpreters have the glaring weakness of       inefficiency because           they   translate statements over and over, they do have some advantages over           compilers.   First, they    are usually easier and faster to use, since the user is not           bothered with        distinct        and time-consuming compile,   link-edit, and execution stages.         Second, they         typically provide users with      superior error messages. Third, an      interpreter for a 3GL      typically requires less storage space in primary     memory than a           compiler for that   language. So they may be ideal for programming environments in           which main          memory is limited, such as on low-end microcomputers. Fourth,           interpreters are     usually        less expensive than compilers.

[8]     Multiprogramming - Multiprogramming is defined as execution of two or more           programs That all reside in primary storage. Since the CPU can execute only one           instruction at        a time, it cannot    simultaneously execute instructions from two or more           programs.   However, it can execute instructions   from one     program then from second           program      then from first again, and so on. This type of processing         is referred to as           “concurrent          execution”.

                             It is    very   useful as most of time CPU remains idle waiting for I / 0 devices           to       complete their       job, as I / 0 devices are very slow.  When I/0 devices are           working for one program,                 CPU executes instructions of    second program.  Thus,           multiprogramming is a   technique which helps in utilising a computer system           more effectively.  It is a   module, which is available in an       operating system.

Multiprocessing: Multiprocessing (or parallel processing) refers to the use of two or more           Central       processing   units, linked together, to perform coordinated work           simultaneously. Instructions are        executed      simultaneously because the available           CPUs can execute different instructions of the same        program or of       different programs    at       any given time. Multiprocessing offers data-processing capabilities   that are not     present when only one CPU is used. Many complex operations can be performed at      the           same time. CPU    can function on complementary units to provide data and control     for one another.

[9]     Distributed Database: When computing resources and database are scattered rather           than centralised,   they are called distributed data processing and distributed database                     systems. Distributed data          processing   refers to a system in which computer           intelligence is located at more than one site and the      actual running of           application programs and processing of data are completed at more than one site.           Distributed data   processing may save a lot of time and money for an organisation. When          processing is         distributed, the data to   be processed usually must be located at the     processing site.     This means that    the data base, or parts of the    data base, must be           distributed. Distributed database systems usually           reduce costs for an organisation           because they         reduce transfer of data between remote sites and the      organisation’s headquarters.       Distributed database systems may also provide    organizations with faster           response      times for filling orders, answering      customer     requests, or providing managers with      information.          They compound the problem of        control        over   the database, increase          problems of security for the      database,    increase       data redundancy and the resulting   danger to data integrity and increase the need      for     more           computer resources.

Object-Oriented Databases: Object–oriented databases (OODB) are a natural extension of           OOP. Like   other database management systems, OODB systems can be either   active           or passive - we will focus on     active          systems. Every object is described by a set    of           attributes describing what the object is (for example,      a set of        program code for an           expert system, a data flow diagram, or a CAD design for a      new product).       Objects           with   similar attributes and behaviors can be grouped into classes and the         attributes           and behaviors       of one object         within a class can be inherited by other objects within          the     same class, which can speed up         application development.

[10]   Batch Processing: A batch of transactions is accumulated, batch totals compiled for it,           the     transactions          transcribed on floppy diskette or other media, the floppy diskette file     sorted by the key   field and processed         against the master file to update the latter and           produce the desired outputs.

Real Time System: The term real time refers to the technique of updating files with           Transaction data immediately after the event to which it relates occurs. This is in           distinction to batch processing which          processes related data in batches at pre-          defined        periods of time. Real time systems are basically on-line system with one           speciality     in inquiry processing. The response of the system to the inquiry itself is           used   to       control the activity. The system is designed to provide immediate information           to       monitor the production processes, it is a real-time system. Real-time systems           usually operate in multi programming      and multi    processing. This increases both           availability and reliability of the system. CPU’s in real time     systems should      possess           the capability of what is known as program interrupts.

On line systems and Batch processing: Online systems refer to processing of individual           transactions          as      they   occur from their point of         origin as opposed to           accumulating them into batches. Aside from         transaction processing and file updating,    inquiries can also be handled by the online processing systems.         On-line Systems           are     in use in various organizations for applications such as Electricity and Gas Boards,           Banking industry, Tour operators and Stock exchanges.

                    On-line systems offer following benefits:

                             (a) Integration of clerical staff with the computer.

                             (b)     Elimination of tedious tasks.

                             (c) Reduction in paper work.

                              (d) Improved accuracy.

                             (e) Improved file updating.

                             (f) Management information more readily available.

                              (g) Improved customer services.

                             (h) Reduced data preparation cost.

[11]   Message Switching: Some organisations with a heavy volume of data to transmit                            use a Special computer for the purpose of data message switching. The computer                    receives       all transmitted data;       stores it; and, when an outgoing communication line                  is       available, forwards it to the receiving point.

          Packet switching: This is accomplished by breaking a message into transmission units,                     Called         packets,       and routing them individually through the network depending on                 the     Availability of a channel         for each packet.    Passwords and all types of data can                 be      included within the packet and the     transmission cost is by packet and not by                    message, routes or distance. Sophisticated error and flow           control procedures are                       applied on each    link by the network.

[12]   Intranets: The Intranet is a type of information system that facilitates                                                                  communication    within the   organization, among widely dispersed departments,                                      divisions, and regional   locations. Intranets connect           people together with Internet             technology, using Web   Browsers, Web Servers and Data Warehouses in a    single                    view. With an Intranet,   access to all information, applications and data can be                      made available     through       the     same browser. The objective is to organize each                                    individual’s desktop with minimal           cost,   time and effort      to be more   productive,            cost-efficient, timely and competitive.

Internet: an internet is a collection of network formed together to share the data on the           web. World          Wide Web (WWW) and the Internet continue to grow in importance as           a        primary business-transaction   delivery       system. Through the Internet, users can           have online interactive communication. At pre-defined timings, those        who have to           communicate together can be online through Internet and have electronic conferences.           This will be truly “many to many”. Similarly, many discussions can be       done through           a        forum where people        post messages for each other and respond to them periodically.          This is similar to   having a bulletin board on      which everyone posts           messages.

[13]   Virtual Memory and Main Memory

          Main memory is a part of the computer hardware, which stores programs, and data           that are in active   use.    Storage locations in main memory are addressed directly by           CPU’s load and store instructions.    Access is      slower from main memory than from           CPU registers because of large capacity and the fact      that it is physically          separated           from the CPU.

                              Virtual memory, on the other hand, is a technique that allows the     execution of a   process, even though     the     logical address space requirement of the    process is           greater        than the physical available main      memory. The        technique works by           dividing      a        program on disk into fixed length pages or into logical,          variable length          segments.    Virtual memory thus extends primary memory by treating disk storage as      a        logical         extension of           the main memory.

                              Virtual memory helps in efficient main       memory utilization. The programs can be         loaded partially in          the     main memory, so more programs can be run at the           same time. Hence, efficient CPU utilization          and better    throughput is possible by using the     concept of virtual memory. Virtual memory makes the task       of       programming much           easier, because the programmer no longer needs to worry about the amount of           physical       or main memory available.

[14]   Distributed System and Computer Network

                             A computer network is a collection of computers and terminal devices connected   together by a        communication system. The computers may include large-scale           computers, minicomputers, terminals,          workstations and miscellaneous devices. Two           computers are said to be inter-connected if they are        capable of   exchanging           information. The connection need not be via a copper wire; but lasers, u-waves           and   earth satellites can also be used. Computer networks increase the reliability of           computer resources        and facilitate         overall system development. They also satisfy the     prime objective of resource sharing   which includes device     sharing, file sharing,           and    program sharing and program segmentation.

                    A distributed system is one in which the computing functions are dispersed           among        several physical    computing elements.      Computer systems are arranged in a computer network, with each system        connected    to one or more other systems.   A distributed   system is both a technological and     organizational concept. Its       premise is that           information processing can be more effective if computer       hardware,   data, software and    in some       cases, personnel are moved physically closer to the         people         who use these resources. In distributed system,         users have greater          control        over their computingenvironment. Network may or may not be a         distributed   system, depending on how it          is used.

[15]   Synchronous and Asynchronous Data Transmission

          Under Synchronous Transmission, bits are transmitted at fixed rate. The transmitter           and receiver both use    the same clock signals for synchronization. Synchronous           transmission allows characters to be sent down the       line without start-stop bits. It           allows data to be send as a multi-word blocks. It uses a group         of       synchronization           bits,   which is placed at the beginning and at the end of each block to maintain           synchronization. Timing is determined by a modem.

                              It is faster way of data    transmission and many data words can be transmitted per second. However,               the synchronous device is more expensive as it must be      smart          enough to differentiate between the    actual          data   and the special           synchronous         characters.

                              On the other hand, in asynchronous           transmission,        each data is           accompanied        by stop (1) and start       (0)     bits that identify the       beginning and           ending of the word.       When no information is being           transmitted i.e.      sender device          is idle, the    communication line is usually high i.e. there is continuous      stream           of       1        .Asynchronous transmission is a reliable transmission system as the extra           start   and    stop   bits ensure that     the sender and receiver remain in step with one another. It             does not require smart   device to differentiate      between actual data and           start/stop               bit. However, it is inefficient as the     transmission speed is slowed down           when there            is huge volume of information to be transmitted.

[16]   Microfilm and Microfiche

                              A microfilm is a 16 millimeters (mm) or 35 mm roll of film contained in           cartridges.   Each roll can hold         2,000 to      5,000 pages of information. It can be read   sequentially          until the desired record is retrieved and       stays in a     continuous form.

                     A microfiche, on the other hand, is 105-mm film cut in 4. 6 inch sheet, each           sheet capable of   reproducing          up to 270 page sized images. It allows direct access           to data        through hunt and storage        procedure.

[17]   Primary Storage and Secondary Storage

                    Primary storage is the basic means of storing data within the CPU itself. It holds           source programs, data files     and frequently used routines. It also provides a           temporary work area for data produced by          intermediate          calculations and           manipulations. Data ready for output are held in primary storage in the    format           required by the source program. Data from primary storage can be retrieved in           millionths of a      second and access is      random.

                    Secondary Storage also called auxiliary     storage is supplementary to the           primary       storage associated          with   the CPU. It is used         to hold programs and data     files not       currently in use. It often has much more     total   storage capacity in relation to   the     primary storage and is less expensive (per unit of storage).      Secondary           storage        can    be sequential access (such as magnetic tape) or    direct access (e.g. magnetic     disk, floppy disk etc.)

[18]   Sequential File Organisation and Indexed Sequential Organisation

                    In sequential file organization, records are written in the same sequence in which           they   are collected, but they   are organized into certain order. Ordering of records           within the file is according to a specific data         field, which is known as key field.           Records appear in sequential file one after another, in key sequence.          Sequential files           can be read and processed only in the order in which they are recorded. Thus, to           process records in           sequential files, it is necessary to read the entire file, from           beginning    to end,         selecting and handling records as      they are encountered. Thus, if        the particular        record required for         processing happens to be the two hundred and           first    record in the         file, the preceding two hundred          records must be read first. Sequential   organization can be      used on all storage media but it is dominant         method for magnetic         tape.

                              On the other hand, Indexed Sequential Organization is a combination of           sequential and direct file         organization. Though the files are recorded serially, in a           logical sequence, indexing or reference       techniques   are used so that access can be on a        random basis as well as sequentially. Thus, any given    file can be   processed           sequentially because of the sequential recording and also the computer has the    ability           to look up    any record in its index and go to that location immediately. Records           are           updated in   place, without the need to        create entirely new files during processing.           This   method of file organization is   used for applications that might        require both           sequential and random access references.

[19]   Multiprogramming and Time Sharing

                    Multiprogramming is a processing mode in which several partially completed tasks           are processed        concurrently. At any given moment, only one task or job is actually           being executed, but within a larger    time   span of several minutes, the computer is           processing several jobs or programs, alternating between        actually       executing, and           performing inputand output activities. Several jobs may be in memory but only one       is           being           executed. When one job needs to do input/ output, another can begin (that is           resume)       execution. Thus two or   more independent programs are executed in the           same time span by interleaving          their execution.

                              The advantage of multiprogramming          is that overall performance of the system         can    be enhanced.        The great    speed of the          central processing unit can be used and          delays in waiting for input or output operations (a        condition that is called, being         input/ output bound) can be avoided.

                              Time Sharing, on the other hand, is a term used to describe a processing system         with a number of independent, relatively low speeds, on-line, simultaneously usable           stations which are geographically     remote         from the computer and from each other.           Each station provides direct access to the central processor for         obtaining instant           responses to the questions asked or statements made in an interactive         conversational           mode. The speed of the system and the use of multi-programming     allows the central           processor to switch from          one using station to another and to do a     part of each job in       the allocated “time         slice” until the work is    completed. The     response is so fast that    the user has the illusion that no one else      is using the computer     which creates an           impression of having a computer for one’s sole use.

[20]   DDL and DML

          The data definition language (DDL) is used to define the physical characteristics of           each record - the   fields within the record, each field’s data type and each field’s           length and logical name. It is also used to specify         relationships among the records.           The primary functions the DDL serves are to:

v    Describe the schema and sub-schemas.

v    Describe the fields in each record and record’s logical name.

v    Describe the data type and name of each field.

v    Indicate the keys of the records.

v    Provide the data security restrictions.

v    Provide means for associating related records or fields.

v    Conceptually it is a link between the logical and physical structure of the database.

          The data manipulation language (DML), on the other hand, provides the           techniques   for processing       the     database such as retrieval, sorting, display and           deletion of data or         record. The main functions of the DML are         following:

v    To provide the techniques for data manipulation such as deletion, replacement,                                        Retrieval, sorting or        inserting of data or records.

v    To enable the user and application programs to process data on a symbolic, logical                        Basis rather than on       a physical location basis.

v    To provide for independence of programming languages. It supports several high level                    procedural languages   such as COBOL and C/C++.

v    To allow the user and application programs to be independent of physical data                                Structures and database           structure maintenance.

v    To provide for the use of record relationships.

[21]   Magnetic disc and Magnetic tape

                             Magnetic discs are the most popular direct access medium i.e. a record can be                                       accessed without having           to       plod through the previous records. Magnetic tape is a                    secondary storage technology. It can only access data           sequentially. It is very                                  economical and widely in use. For details, refer to Chapter 5,          Section 5.2 & 5.4.

[22]   Cathode Ray Tube (CRT) and Flat Panel display devices

                    CRT devices use a large tube-type element. Inside the tube is a gun that lights up           the phosphorescent        pixels on the screen surface. It is inexpensive, reliable but bulky           and provides limited resolution.

                    Flat-Panel devices, on the other hand, use either a         liquid crystal display (LCD) or      gas plasma technology.           Gas-plasma displays provide   better resolution but are           expensive. Flat panel displays are light weight and       compact.

[24]   Master file and Transaction file

                    Master file is the file containing relatively permanent information, which is used as           source of reference          and    is generally updated periodically.

                    Transaction files are      created from source documents used for recording events or      transactions.         These are    details files, and the information is used for updating the           master files.

           For details, refer to Chapter 1, Section 1.9, and Pages 25-26 of study material.

[26]   Ring Network and Star Network:

                   In Ring Network topology, the network cable passes from one node to       another until all nodes are         connected in         the form of a loop or ring. There is a direct point-to-point link between         two neighboring   nodes.         These links are      unidirectional which ensures        that transmission by a node traverses the     whole          ring and      comes back to the     node,           which made the transmission.

                              In Star Network topology, the network is     characterized by communication                     channels emanating from       centralized computer system. That is, processing           nodes in a   star network          interconnect directly with a      central system. Each terminal, small      computer or larger         main-frame can communicate only with the           central         site and not           with other nodes in the network. If it is desired      to transmit information from one node to       another, it   can be done only by sending the details to the central node, which in    turn sends them to          the destination.

                             Ring networks offer high performance for a small number of workstations or for          larger networks where    each station has a similar workload. These networks can           span longer distances than star networks and      are easily     extendable.

                              A star network is particularly appropriate for organizations that require a           centralized database or a         centralized processing facility. In a star network, it is easy           to add new nodes and also remove nodes. A         node failure does not bring down the           entire network. It is easier to diagnose network problem through a   central hub.

[27]Network-attached storage and direct-attached storage:

                             Network-attached storage (NAS) is a dedicated shared storage solution that           attaches       to a network          topology,     Becoming immediately and transparently available     as      a network resource for all clients. NAS is platform          and    operating system         independent.         It can be attached without powering down the network, and requires       no      changes to   the existing file servers. A NAS device is typically a un           performance,        single-purpose      system or component. It serves specific storage needs           with its own          operating system   and integrated hardware         and software. NAS devices        are well       suited to serve heterogeneous networks.       They enable file and data sharing       among        different types of clients.

                              Direct attached storage (DAS), on the other hand, is a storage device that connects      directly to a single          server. Network workstations access the server to connect to this    storage. Because the server may be    handling     distributed applications such as e-mail           or databases, the performance of DAS is typically not    as high as that of networked           storage. DAS uses the security features of the server’s network operating     system.

[28] Logical record & physical record

[29]   Audio Conferencing:

                   It is the use of audio communication equipments which allow the user to           communicate with         geographically     dispersed persons. Audio conferencing does not    require a computer but requires a two        way audio   communication facility.  Guidelines   to make Audio conferencing more efficient are as stated         below:

                   (a) All the participants must have an opportunity to speak.

                   (b) Number of participants must be kept to manageable size.

                   (c) Copy of conferencing agenda must be sent to all the participants in advance                                       through FAX.

                   (d) Participants must identify themselves.

                   (e) Conferencing discussion must be recorded.

                   (f) Hard copy of the discussion must be prepared and should be sent to all the                                           participants for approval.

          Video Conferencing:

                   It is the use of television equipment which allows the user to communicate with           geographically dispersed         persons. The equipment provides both sound and picture.           The participant can see and hear each other        and it          does not required computers. Participants gather in specially equipped rooms having audio and video facility.

          There are three types of Video Conferencing:

                   (a) One way Video and Audio: In this case, audio and video is traveled only in one                                       direction e.g.        Television.

                   (b) One way Video and Two way Audio: In this case, audio is transferred in both                                       directions but video is     transferred in one direction e.g. Discussion of News Reader                            with field correspondent.

                   (c) Two way Video and Audio: In this case, audio and video is transferred in both                                       directions between sender and receiver e.g. Discussion of persons between different                      studios of a News Channel.

[30] Client server model & peer to peer model 

[23]   Client-server model and Peer-to-Peer model of networking architecture

                   in client server model number of computers, known as clients are connected to a           single host computer known as server.

                   In peer to peer model, all the computers are interconnected whit each other. There is       no concept of server and clients. All computers behave as  server as well as clients.

                   Client server  uses a dedicated server which provides various services to client like           hardware , software and data access. Different types of servers can be file fax print of           database server. It can share disk storage and printers attached whit the server. It is           suitable for large organization having large numbers of nods; its data transfer speed is           fast. Failure of sever brake down of entire network. Servers are not use as data entry   all computer are not used as employed. Client required connecting to server in        particular mode. Clients are dumb or intelligent terminals. Is use full where data      security is prime.

                   In peer to peer model non dedicated server used non dedicated server can also be used   as a node for data entry, processing and output operations. All computer can share the           data / resources of each other. It is suitable in small organization having less number of                                                                                                                          nodes up to ten. Data transfer speed is less which decreases even further with the           increase in number of computers. Failure of one computer not affect  the working of           other, only the data stored on the faulty computer will not be accessible to other           computers. all the computers are full employed. Computer are connected at any point in network like ring network. All computer are use intelligent terminal.  This architecture is used when security is not bigger issue.

[31]   Third Generation and Fourth Generation Languages

Third Generation Languages are called procedural languages and they are procedure           oriented.               They employ plain English like and mathematical expressions.  They           are intended for professional   programmers, and require specification of how to           perform task.  Programmes written in third          generation languages are also difficult to       debug and usually translated through compiler.  Code is       difficult to learn,           understand and maintain.  These languages were originally developed for batch           operations and are typically file oriented.  FORTRAN, COBOL etc. are examples of           third generation    languages.

Fourth Generation Languages (4GLs), on the other hand, can be used by both           programmers and          non-programmers.  4GL uses English like instructions, has           limited mathematical manipulation   capability.  It offers automatic report           formatting, sequencing and record selection by user given       criteria.  However, 4GLs           are less efficient than third generation languages.  They require specification      of           what task to perform and the system determines how to perform that task.  4GL           requires fewer       instructions, code is easy to maintain and understand.  Many features of 4GLs can be learned quickly.         4GLs are more structured and are data      base oriented.  Generally, these are available in two types (I)       Production Oriented      and (ii) User Oriented.                       

[32]             Fixed Length Fields and Variable Length Fields

                   Under Fixed Length Fields scheme, fields are simply placed in sequence one after           another.      Thus, while designing physical records, it conserves storage space.  In        this scheme, a trailing blank pad character field and leading zero pad numeric          fields is used.  Hence, under fixed length field           scheme we know the exact location   within a file for each of the fields of a physical record.

Variable Length Fields scheme makes the location of a particular field and a particular           record         irregular.  That is, depending on which records exist and the precise values           for fields, different records       and fields will be in different locations.  A common way to           handle variable length field is to break the relation into a fixed length physical   records containing all fixed length fields and one or more variable      length physical      records. In personal computers, this is how many DBMS handle a memo field    which is       a variable-length field.            

                                                                                                                                      Word & Excel

[1]               Text Editor and Word Processor:  Text Editors can edit plain text only and offer           no formatting features. The user must hit ENTER at the end of each line.  They          are           good for short documents or e-         mail text bodies, HTML, web pages and           programs.

                   Word Processors edit text and allow embedded formatting for words, paragraphs           and whole   documents.  They also support word wrap, margins and different    typefaces in the same document.   Word processors are specifically designed to prepare     such document material as letters and reports whereas text editors are designed to   manipulate non-document instructions in computer programs or          data.  Text editors           lack the text formatting and document printing capabilities of word processors.                            

[2]     (Typeface & Font)         Typeface is the set of characters making up an alphabet that all share similar         design         characteristics       this says nothing about size, weight, style, etc.).  A font is      typeface of a particular   point size, weight,                    and style.  For example, “Times-Roman”   is a typeface, but “Times-Roman, 12           point, bold, italic” is a font.

five views offers by PowerPoint :

(1) Normal View: This view gives small pane for text. It allows the user to frequently     switch between text          and    objects on the slide.

(2) Outline View: This view gives largest pane for text; hence it is easy to work on a           presentation. On the       other hand, text is spread over several lines in normal view           because the space for text is less.

(3) Slide View: This view makes it convenient to insert objects and modify them. This     view shows how the      text    and objects appear on each slide. Using this view, user can     work only on one slide at a time.

(4) Slide Sorter View: This view helps in moving the slides around but text/objects can not be rearranged on      individual slides. This view shows all the slides at one time.

(5) Slide Show View: This view shows all the slides of the presentation one by one           automatically if the time of       each slide has been set up or slides can be viewed one by           one on mouse click.

Various tools available to protect the information from intrusion and misuse are discussed below:

(1) Firewalls: These are the software which is installed on the web server to protect the           server from hacking.     Hackers are mischief makers who intentionally disable the site           and whenever any user tries to           open that site,       its home page is not displayed.           However, Firewall can also be implemented with the      help of hardware like      Nokia           Checkpoint.

(2) Encryption: Before the transmission of data like transfer of credit card number on   telephone line during E-      Commerce transactions, data is encrypted so that no person    can trap the data on the way. Encryption    of data        can be performed with the help of      hardware as well as with the help of software.

(3) Message Authentication: Before providing access of data to the user, authentication of           user can be done with the help of passwords. Organisation server may also be           configured to accept the message only         from the      known persons.

(4) Site blocking: It is a software based approach which restricts the users to access      certain sites. For     example,      in certain organisations, servers are configured in such a        manner so that user cannot open the    site. For      example resume posting sites like       Naukri.com, jobahead.com etc.

(5)     Mail Merge:

                             Mail Merge is one of the most important tools of MS-Word. It is       efficient and less time         consuming way of preparing mass mailing for a list of addresses.    It is a tool for producing repetitive     document, and gives       the flexibility, in    personalizing each copy of it with information such as names, addresses, dates etc.

                    Components of Mail Merge: Mail merge is built around two sets of components –           main document and data        source. The main document is a form letter. It contains           merge fields (or field names) where data would be         merged. The field names would be           replaced with the field contents coming from the data source at the time of merging.           The data source is a file that contains information like name, address etc., which is           merged with the    main document to create a final product. The data source can be           very easily picked up from Access database,          an Excel spreadsheet, Microsoft Address           Book or one created in MSWord.

 MS-Word offers several useful tools for efficient writing and to increase efficiency.

                    Auto Correct: Auto Correct has a dictionary of its own which contains a list of           commonly mistyped words. The user can customize this dictionary by making     additions to it of the words one mistypes The user may also provide the correct spelling       of the word with which Word should replace the mistyped       one. Once   the     entry is        in the Auto Correct dictionary, Word automatically makes correction of such    words.

                    Auto Text: Auto Text is a unique feature of Word. It allows the user to store           formatted text, even paragraphs and graphics. These can be recalled by   pressing some           keys. Auto Text is like Auto Correct in that it also has    dictionary of its own and can be customized. However, AutoText has to be    explicitly called to allow it to work.    AutoText has an AutoComplete tip that will complete the                   text without the     user   having to type the entire               word.

Spelling and Grammar: As English is not a very phonetic language; the spelling of some           words can be learnt only by memorizing. As an example, a word ‘achieve’ has to be           spelt ‘achieve’ or ‘acheive’. One                  of the first tools that the word processors came           equipped with to beat the electronic typewriter was the            spell check. The spell           checking function checks each word in the document against the dictionary and             underlines it with a red curly line if a word with wrong spelling appears or is not           found in the dictionary.            There are numbers of options available, which the user can           set in the software.

Thesaurus: The thesaurus is a useful writing tool that comes along with the word           processor. If the user is   unhappy with the choice of a word, he can easily look up        the thesaurus to find a more precise word.

Find and Replace Test: ‘Find’ helps to locate specific text in a document while ‘Replace’           helps to substitute it with new text. The user has the option of replacing all words           with one keystroke if he is sure that all the   entries of that word need to be replaced.           However, if one wants to replace only some of the entries of the         word then MS-Word           will take one through the document, entry after entry.

                                                                                                                                                          Full From

1        IRR – It is financial function and returns the internal rate of returns for series of                                                cash flows.

2        LEN – It is text function and returns the number of characters in a text string.

3        DMIN – It is a database function and returns the smallest number in the field of                                        records in the        database     that matches the condition specified by the user.

4        POWER – It is a mathematical function and is used to calculate the value of one                                                         number raised to the       power of another number (xy).

5        MOD (X/Y): It is a mathematical function.  It returns modulus or remainder when x                                                               is divided by y.

6        NPV (values, rate): This function is used to calculate net present value of an investment                                                                                       based on     discount      rate and a series of future payments.

7        LOG(x)                : Returns the logarithm of a number to the base 10.

8        ROUND (x, n): To round off the number x to n number of decimal places e.g. if x =                                                                                  2.1752 and n = 2 then   =       ROUND (x, n) will return 2.18.

9        Count (range): This function is used to count the number of items in the range of cells                                                           ignoring the blank          cells.

10      DMA         X: It is a database function. It returns the largest number in the field (column)                                                 of       records in the        database     that matches the conditions specified.

11                VAR: It is a Statistical function, which is used to estimate the variance based on a                                       sample.

12      SUM: It is a statistical function, which adds all the numbers in a range of cells.

13      INT: It is a mathematical function that computes the integral part of the value. All                  fractional values are       truncated     and only the integral part of the value is retained.

14 FV: It is a financial function which calculates the future value for a series of equal                               investments (also called annuity) earning at fixed periodic rate of interest.

15      RATE         : it is a financial function it returns the interest rate per period of a loan or                                                           an annuity.

16.     ABS  : it is a mathematical function; it returns the absolute value of a number, a                                                          number without its sing.

17      PPMT         :        it is a financial function, which returns the payment on the principal for a                                    given investment based on periodic, constant payment & a constant interest rate.

18. PMT     :-       it is financial  function that is used to calculate the loan payments based on                                                 he rate of interest, term of the loan and the principal amount.

19.     INT             : it is a mathematical function, which computes the integral part of the                                                       value. All frictional values ate truncated and only the integral part of the value                                is retained.

20 .NPER   :        it is a financial function which retunes the number of periods for an                                                           investment based on periodic constant payment and a constant interest rate.

21 AVERAGE     : it is a statistical function which calculated the average of the values in                                                                the list of its arguments.

22 PROPER        :        this is a text function which capitalizes the first letter in each word of a                                                                    text string and converts all  other letters to lowercase letters.

                                                                                                                                                          Short Note

1        FIRMWARE: Firmware or micro programs refer to a series of special program           instructions.  The most basic operations      such as addition, multiplication etc, in a           computer is carried out by hardwired circuits.  These fundamental tasks are then           combined in the form of micro programs to produce higher level operations such as           move data, make comparison etc.      These micro programs are called firmware because they deal with very low level machine operations and thus essentially          substitute for additional hardware.  Firmware is held in the CPU in a special control     storage device.

2        Data Dictionary – Data dictionary is a centralized depository of information in a           computerised form about the data in the     database.  The data dictionary contains      the scheme of the data base i.e. the name of each item in the data base and a   description and definition of its attributes along with the names of the programs        that use them and who is responsible for      the data; authorisation table that specifies users and the data and programs authorised for their use.  These descriptions          and    definitions are referred to as the data standards.  Maintenance of a data dictionary is    the responsibility of the data base administrator.It is useful in the following ways:

Ø    If any data fields are to be altered or eliminated, it helps to Identify all programs                     that might require modifications

Ø    Useful for protecting data integrity of the database data.

Ø    Helps programmer to quickly locate blocks of codes that can be reused in new                         application.           

3        Storage Area Network – SAN is a dedicated centrally managed, secure information           infrastructure which enables any to   any interconnections of servers and storage           system.  SAN connectivity is accomplished independently of the LAN.  The storage        is accessible from the server so users can access any storage device on the SAN       regardless of the physical           location of the storage or user.  A key feature of SANs is          their heterogeneous nature, with the ability to concurrently provide           storage for servers running differing operating systems. This means that organisations using      Solaris, Linux, HP/UX,           Windows 2000 and Netware Servers can all access a     single SAN.

Ø    It facilitates universal access and sharing of resources

Ø    It improves information protection and disaster tolerance.

Ø    A SAN simplifies and centralises resource management.

Ø    E-Commerce and globalisation has caused the necessity of SAN.

Ø    Zero latency-information can be exchanged immediately.

Ø    Its ability to continually adapt, while immediately accessing and processing                                     information

Ø    It supports distributed computing

Ø    Full integration with different hardware, software from different vendors is                                                 possible.

4        Microsoft Windows:  It is an operating system developed by Microsoft Inc.  First           time it was launched in 1983 and later on   a modified version Windows 3 was           introduced in 1990.  Subsequently, Microsoft revised and enhanced its operating           system         almost every year.  Windows 95/98 and Windows 2000 operating systems           became very popular.  Now a day,     Windows XP is most commonly used operating           system in personal computers.  Microsoft Windows operating system has    following           salient features, which made it very popular

Ø    Friendlier user interface

Ø    Graphic user interface

Ø    32 bit architecture

Ø    Provides multitasking environment to run multiple tasks concurrently

Ø    Long file name permission

Ø    Easy navigation routes

Ø    Plug and play technology enabling user to connect various peripheral devices or                             add-ons with minimum of fuss.

Ø    Designed for easy access to network resources

Ø    Facilitates gateways to Internet, Fax

Ø    Backwardly compatible

Ø    Allows a developer to produce software applications to run on Windows without                    the need to notify Microsoft.                                 

5        Voice Messaging: This communication approach is similar to Electronic mail except in           this approach, audio      messages rather than text messages are processed. A sender           speaks on the phone giving the name of the          recipient and message. Sender’s voice           signals are converted to digital signals and stored. The system then   transfers the           message to the recipient. The message is converted back to analog form when it is           received by the recipient. Recipient hears the same voice as it had been spoken by the           sender. Voice messaging requires      a computer with the ability to store the message by           converting it into digital form and converting back to analog form upon retrieval. Main           advantage of voice messaging over electronic mail is that the sender need not have        to           type the message.

6        Wireless Networks: People on the road often want to use their portable computers like           Laptop or Notebook       computers to send and receive electronic mails, read remote files           from the server of their office and to surf the         Internet from anywhere on land, sea or           air. Since a wired network is impossible in cars and aeroplanes, hence       it resulted in the           development of wireless network. WAP (Wireless Application Protocol) is the protocol           used in        Wireless communication. Laptop computers with wireless card are available           in the market. Wireless technology     known as Bluetooth allows the user to transfer the           data between computer and Mobile Phone/Digital Camera.    Airports and some Indian           Universities have been converted to Wireless fidelity (Wi-Fi) zones which are allowing

                    Users to use Internet services anywhere within the premises of Airport. Wireless           networks are of great use for    those persons who remain away from their home/office for           most of the time. Another use of wireless network is        for the rescue workers at the           disaster sites like fires, floods or earthquake sites where telephone system    Gets           destroyed.

7        File Management System: In this system, different users work on their independent           computers and maintain          their own data files. Each user has its own application           software according to the requirements which was either         developed in-house or got           developed from external software agency according to the requirements. Instead of           getting integrated software developed, different users have independent modules for data processing. Such   system of maintaining files creates many problems as discussed         below:

          (a) Data redundancy: When same data files are stored at different locations, then it is                      called data redundancy. It causes problem when the data has to be updated.                                             Different               users may use same data as to occur inconsistency among different files.

          (b) Lack of Data integration: Data files of different users are not integrated with each                    other; therefore changes made by one user are not made in each file automatically. It                 is an expensive and time consuming process for an organisation.

          (c) Data inconsistency: Lack of Data integration creates data inconsistency. When at a                    particular time, data       stored in different files does not reconcile with each other, and             then it is called data inconsistency.

          (d) Program-data dependence: Software modules being used by different users are                                    developed in high level programming languages like BASIC, COBOL etc. These                    high level languages use different file formats.      Therefore, when program written in one        programming language is required to be changed in another language, then it becomes   essential to change the format of data files also.

8        Diagnostic Routines: It is system software which is usually a part of operating system           and is provided     by the computer manufacturer. These are those programs which help           the user in debugging of program     as well as    to find out the details of various           equipments used in the computer, like:

                   1. What type of Processor is installed in the computer like P-III or P-IV and its                                 speed?

                   2. What is total amount of main memory like 128MB/256MB?

                   3. What type of keyboard is attached with the computer like 101 Keys/104                                                            keys/Multimedia Keyboard?

                   4. What is display type like VGA/SVGA?

                   5. What type of mouse is attached with computer like 2 buttons/3buttons/scroll                                  mouse/Mechanical          Mouse/Optical Mouse?

                   6. Is separate math coprocessor present in computer?

                   7. Where is BIOS (Basic I/O) manufacture like AWARD BIOS or ANI BIOS?

9        White Box Approach for Audit: Presently, computer system has progressed to a point           where entire                    processing cycle occurs within the computer system. Therefore,           traditional audit trial has disappeared. Hence,     it becomes necessary to examine the           internal working of the computer system. The auditor can verify the   progress himself           and get technically satisfied that the system, internal checks, controls, error detection           and    data security procedures are satisfactory. Auditor can use test checks to keep the           system in operation. By   acquiring the necessary skills, the auditor can use the     computer itself as an audit tool to improve the quality of      his own audit and can    reduce time spent on detailed verification of transactions. In this type of white box   approach, the auditor’s primary concern includes the system of controls, examination      and testing of computer implemented controls.

10                WORM Disks: It stands for write once, read many optical laser disks, or WORM           disks.           These are used by end    user companies to store their own proprietary           information.          Once the data have been written to the medium,   they only can be read,           not updated or      changed. The PC version of a WORM disks cartridge, which looks like a        5¼ inch       version of the 3½ inch diskette, has a capacity of 200 MB. Access times for           CD-ROM    and WORM          drives tend to be quite slow by hard disk drive standards,           ranging from        100 to 300 milliseconds. The WORM          disks cartridge is a feasible           alternative to         magnetic tape for archival storage; for example, a company might           wish to keep a       permanent record of all financial transactions during the last year.           Another popular   application of       WORM disks is an information system that requires           the merging of text          and images which do notchange for a         period of time.

11      Bar Code Reader: It is an input device, most commonly found in supermarkets and           departmental stores. It    converts the bar code, which is a pattern of printed bars on           products, into a product code by emitting a laser beam to reflect off the bar code           image. A light sensitive detector identifies the bar code image by recognizing       special bars   at       both ends of the image. Once the detector has identified the bar code, it converts the           individual    bar patterns into numeric digits and feeds that number to the computer,     just as though the number had been         typed on a key board. The special bars at each     end of the image are different, so the reader can tell whether          the bar code has been read      right side up or upside down. After the bar code reader converts a bar code image    into    a number it feeds that number to the computer, as if the number had been typed on a    keyboard.

          It provides following advantages:

                   Improves accuracy of data entry

                   Better customer service

                   Faster check out at the point of sale

                   Greater control and reliability of inventory records

                   Most widely used input device after the keyboard and mouse.

12      Webcasting or push technology is web-based technology. This allows users to     passively receive broadcast information rather than actively search the Web for        information. Push technology allows users to choose from a    menu of sources, specifying      what kind of information they want to receive. Once selected, the information is    automatically forwarded to the user. Internet news services, which deliver the day’s activities to the user’s      desktop, are an example of push technology. Users can also         download software, select the frequency with           which they will receive services, and   subscribe to a variety of information sources. There is very little cost

                    Involved to the user for push services because information is delivered with           advertising, and users view their        custom-tailored news off-line. Webcasting eliminates           the frustration of the user which he/she faces while         surfing the Internet to get right           kind of information.

13      World Wide Web: The World Wide Web (WWW) or the Web is a component of the           Internet that provides      access to large amounts of information located on many           different servers. The Web also provides access to           many of the services available on the     Internet. The fundamental unit of the Web is the Web page. The Web          page is a text           document that contains links to other Web pages, graphic and audio files, and other           Internet

                    Services such as file transfer protocol (FTP) and E-mail. Tens of thousands of Web           servers are connected to the Internet running special software in the servers allowing    the users to access Web pages. A user can         access directly any Web page on one of       these servers and follow the links to other pages. This process creates        a Web of links       around the world and so the name World Wide Web.

14      Electronic spread sheet: It is powerful automated general purpose specification   software. It can be used to   solve almost any problem involving numbers and           formulae. Once the data is entered in an electronic spread        sheet, a variety of calculations can be applied. Electronic spreadsheet software has dozens of built-in-   functions. Some spreadsheets include mathematical, statistical and financial functions   that permit the user to     analyze the data contained on the spreadsheet quickly, easily          and accurately. Changes can be made quickly           and easily on a spreadsheet since the          values and formulas, once inserted, are all stored electronically in    primary storage.   Therefore, electronic spreadsheet is widely used to test the effect of changes. This is called        뱖hat if? Analysis. In situations where a large number of variables mathematically affect   outcome of certain

                    Events, electronic spreadsheet allows variation in some of these parameters and their           effect on final outcome    can be immediately calculated. Spreadsheet graphics permit           presentation of complex numeric information        contained within an electronic           spreadsheet in a more comprehensive form using charts and graphs. They are Easy to use and are user friendly. They have built in commands for performing many common        functions and    thus can process and analyze data quickly. The data management    software in electronic spreadsheet allows         the use of spreadsheet commands to sort,    search and extract selected data and later on use it in a variety of         ways, including     mailing lists, personnel lists, work schedules, training schedules, customer / client

          Lists, rate tables and daily / weekly logs etc.

          (I) Cell Contents: The intersection of a row and a column is called a cell. Different types                    of data can be       entered into a cell. The four commonly used types of cell data are:                                       Label? A label is any string of alphanumeric text, used either to enter alphanumeric                 values in cells or to enter descriptive data or titles to make the contents easier to                         understand. . Numeric value. A numeric value is a number on which the                                                           spreadsheet can perform calculations.

                   . Formula? A formula may include numbers, mathematical operators, mathematical                    functions supported by                       the spreadsheet, and cell addresses. . Date and Time? It                is normally used in a spread sheet to display                            the actual date and time                                            whenever the spreadsheet is opened for use, or if calculations are to be     Made based                             on date or time.

          (ii) Range of cells: Many spreadsheet operations involve a range of cells instead of a           single cell. A range of     cells may involve many cells and entering every individual cell for           an operation to be performed on them may be cumbersome and time? Consuming.           Therefore, all spreadsheet packages allow the use of following types of cell ranges:

                             . Row Range? It is used to include a set of adjacent cells in the same row.

                             . Column Range? It is used to include a set of adjacent cells in the same column.

                             . Block Range? It is used to include a set of adjacent cells in a rectangular group                                       of       cells.

15      Relative and absolute cell addresses: When a formula entered in a cell has references to           other cells, by        default, the references are relative to the cell with the formula in it.

                   The facility of relative cell addressing is of great help in creating spreadsheet quickly           by entering the formula once and copying them to other cells. If a formula requires a   cell address, which should not change even       when the formula is copies to other    cells, absolute cell addressing can be used to accomplish this. Depending on           the requirement,    a cell reference can be made fully or partially absolute as follows:

                   . Precede both the column letter and the row number of the cell with a dollar sign to                              make both column and   row references absolute.

                   . Precede only the column letter of the cell with a dollar sign to make only the                                            column reference absolute.

                   . Precede only the row number of the cell with a dollar sign to make only the row                                       reference absolute.

16      Graphics feature: Most spreadsheet packages come with presentation graphics feature,           which enables to create graphs and charts from numerical data stored in a spreadsheet.           The most popular types of graphics             and charts supported for graphical           representation of numerical data are line graphs, bar charts and pic                              charts. This           feature         is very useful in presenting spreadsheet data in easier to understand visual forms           Because most people find it difficult to interpret a table of numbers.

17. (I) Integrated Test Facility [ITF]: It is a particular form of test data involving the           establishment of a 밺ummy? Entity through which data may be processed. For example,           a fictitious trading branch might be set                 up.

(ii) Clip Gallery: The collection of multimedia effects such as sound and videos in WORD                 2000 is known as                     clip gallery. It is very user-friendly.

(iii) Hacking: Also known as cracking because the person cracks the log-in codes and sequences of a system. It                 is the unauthorized entry by a person into a computer    system or network.

(iv) Slides in PowerPoint: Every PowerPoint presentation involves the creation of a series of           slides. These slides                   can have text or objects displayed on them. They help in working       with presentations more conveniently.

(v) Program Flow chart: It is the most detailed flowchart and is concerned with the           logical/arithmetic operations             on data within the CPU and the flow of data between       the CPU on the one hand and the input / output                               peripherals on the other.

(vi) Charts in Spreadsheet: Charts create a picture? In the minds by giving a visual           comparison, pattern and                                       analysis of numbers. They make data interesting and      attractive to read and interpret.

(vii) Tally: It is user-friendly accounting software which facilitates various kinds of           accounting solutions in a very           simplified format.

(viii) Decision Table: It is a table which may accompany a flowchart, defining the possible           contingencies that may             be considered within the program and the appropriate           course of action for each contingency.

Data Base

DAVERAGE   Returns the average of selected database entries

DCOUNT   Counts the cells that contain numbers in a database

DCOUNTA   Counts nonblank cells in a database

DGET   Extracts from a database a single record that matches the specified criteria

 DPRODUCT   Multiplies the values in a particular field of records that match the criteria in a database

DSTDEV   Estimates the standard deviation based on a sample of selected database entries

DSTDEVP   Calculates the standard deviation based on the entire population of selected database entries

DSUM   Adds the numbers in the field column of records in the database that match the criteria

DVAR   Estimates variance based on a sample from selected database entries

DVARP   Calculates variance based on the entire population of selected database entries

GETPIVOTDATA   Returns data stored in a PivotTable

BESSELI   Returns the modified Bessel function In(x)

BESSELJ   Returns the Bessel function Jn(x)

BESSELK   Returns the modified Bessel function Kn(x)

BESSELY   Returns the Bessel function Yn(x)

BIN2DEC   Converts a binary number to decimal

BIN2HEX   Converts a binary number to hexadecimal

BIN2OCT   Converts a binary number to octal

COMPLEX   Converts real and imaginary coefficients into a complex number

CONVERT   Converts a number from one measurement system to another

DEC2BIN   Converts a decimal number to binary

DEC2HEX   Converts a decimal number to hexadecimal

DEC2OCT   Converts a decimal number to octal

DELTA   Tests whether two values are equal

ERF   Returns the error function

ERFC   Returns the complementary error function

GESTEP   Tests whether a number is greater than a threshold value

HEX2BIN   Converts a hexadecimal number to binary

HEX2DEC   Converts a hexadecimal number to decimal

HEX2OCT   Converts a hexadecimal number to octal

IMABS   Returns the absolute value (modulus) of a complex number

IMAGINARY   Returns the imaginary coefficient of a complex number

IMARGUMENT   Returns the argument theta, an angle expressed in radians

IMCONJUGATE   Returns the complex conjugate of a complex number

IMCOS   Returns the cosine of a complex number

IMDIV   Returns the quotient of two complex numbers

IMEXP   Returns the exponential of a complex number

IMLN   Returns the natural logarithm of a complex number

IMLOG10   Returns the base-10 logarithm of a complex number

IMLOG2   Returns the base-2 logarithm of a complex number

IMPOWER   Returns a complex number raised to an integer power

IMPRODUCT   Returns the product of two complex numbers

IMREAL   Returns the real coefficient of a complex number

IMSIN   Returns the sine of a complex number

IMSQRT   Returns the square root of a complex number

IMSUB   Returns the difference between two complex numbers

IMSUM   Returns the sum of complex numbers

OCT2BIN   Converts an octal number to binary

OCT2DEC   Converts an octal number to decimal

OCT2HEX   Converts an octal number to hexadecimal

Financial

ACCRINT   Returns the accrued interest for a security that pays periodic interest

ACCRINTM   Returns the accrued interest for a security that pays interest at maturity

AMORDEGRC   Returns the depreciation for each accounting period by using a depreciation                                                 coefficient

AMORLINC   Returns the depreciation for each accounting period

COUPDAYBS   Returns the number of days from the beginning of the coupon period to the                                                 settlement date

COUPDAYS   Returns the number of days in the coupon period that contains the settlement date

COUPDAYSNC   Returns the number of days from the settlement date to the next coupon date

COUPNCD   Returns the next coupon date after the settlement date

COUPNUM   Returns the number of coupons payable between the settlement date and maturity date

COUPPCD   Returns the previous coupon date before the settlement date

CUMIPMT   Returns the cumulative interest paid between two periods

CUMPRINC   Returns the cumulative principal paid on a loan between two periods

DB   Returns the depreciation of an asset for a specified period using the fixed-declining balance method

DDB   Returns the depreciation of an asset for a specified period using the double-declining balance method or                 some other method you specify

DISC   Returns the discount rate for a security

DOLLARDE   Converts a dollar price, expressed as a fraction, into a dollar price, expressed as a   decimal number

DOLLARFR   Converts a dollar price, expressed as a decimal number, into a dollar price, expressed as a fraction

DURATION   Returns the annual duration of a security with periodic interest payments

EFFECT   Returns the effective annual interest rate

FVSCHEDULE   Returns the future value of an initial principal after applying a series of compound interest rates

INTRATE   Returns the interest rate for a fully invested security

IPMT   Returns the interest payment for an investment for a given period

ISPMT   Calculates the interest paid during a specific period of an investment

MDURATION   Returns the Macauley modified duration for a security with an assumed par value of $100

MIRR   Returns the internal rate of return where positive and negative cash flows are financed at different rates

NOMINAL   Returns the annual nominal interest rate

ODDFPRICE   Returns the price per $100 face value of a security with an odd first period

ODDFYIELD   Returns the yield of a security with an odd first period

ODDLPRICE   Returns the price per $100 face value of a security with an odd last period

ODDLYIELD   Returns the yield of a security with an odd last period

PRICE   Returns the price per $100 face value of a security that pays periodic interest

PRICEDISC   Returns the price per $100 face value of a discounted security

PRICEMAT   Returns the price per $100 face value of a security that pays interest at maturity

PV   Returns the present value of an investment

RECEIVED   Returns the amount received at maturity for a fully invested security

SLN   Returns the straight-line depreciation of an asset for one period

SYD   Returns the sum-of-years' digits depreciation of an asset for a specified period

TBILLEQ   Returns the bond-equivalent yield for a Treasury bill

TBILLPRICE   Returns the price per $100 face value for a Treasury bill

TBILLYIELD   Returns the yield for a Treasury bill

VDB   Returns the depreciation of an asset for a specified or partial period using a declining balance      method

XIRR   Returns the internal rate of return for a schedule of cash flows that is not necessarily periodic

XNPV   Returns the net present value for a schedule of cash flows that is not necessarily periodic

YIELD   Returns the yield on a security that pays periodic interest

YIELDDISC   Returns the annual yield for a discounted security; for example, a Treasury bill

YIELDMAT   Returns the annual yield of a security that pays interest at maturity

ADDRESS   Returns a reference as text to a single cell in a worksheet

AREAS   Returns the number of areas in a reference

CHOOSE   Chooses a value from a list of values

COLUMN   Returns the column number of a reference

COLUMNS   Returns the number of columns in a reference

HLOOKUP   Looks in the top row of an array and returns the value of the indicated cell

HYPERLINK   Creates a shortcut or jump that opens a document stored on a network server, an intranet, or the                                      Internet

INDEX   Uses an index to choose a value from a reference or array

INDIRECT   Returns a reference indicated by a text value

LOOKUP   Looks up values in a vector or array

MATCH   Looks up values in a reference or array

OFFSET   Returns a reference offset from a given reference

ROW   Returns the row number of a reference

ROWS   Returns the number of rows in a reference

RTD   Retrieves real-time data from a program that supports COM automation

TRANSPOSE   Returns the transpose of an array

VLOOKUP   Looks in the first column of an array and moves across the row to return the value of a cell

Math and Trigonometry

ACOS   Returns the arccosine of a number

ACOSH   Returns the inverse hyperbolic cosine of a number

ASIN   Returns the arcsine of a number

ASINH   Returns the inverse hyperbolic sine of a number

ATAN   Returns the arctangent of a number

ATAN2   Returns the arctangent from x- and y-coordinates

ATANH   Returns the inverse hyperbolic tangent of a number

CEILING   Rounds a number to the nearest integer or to the nearest multiple of significance

COMBIN   Returns the number of combinations for a given number of objects

COS   Returns the cosine of a number

COSH   Returns the hyperbolic cosine of a number

COUNTIF   Counts the number of nonblank cells within a range that meet the given criteria

DEGREES   Converts radians to degrees

EVEN   Rounds a number up to the nearest even integer

EXP   Returns e raised to the power of a given number

FACT   Returns the factorial of a number

FACTDOUBLE   Returns the double factorial of a number

FLOOR   Rounds a number down, toward zero

GCD   Returns the greatest common divisor

LCM   Returns the least common multiple

LN   Returns the natural logarithm of a number

LOG10   Returns the base-10 logarithm of a number

MDETERM   Returns the matrix determinant of an array

MINVERSE   Returns the matrix inverse of an array

MMULT   Returns the matrix product of two arrays

MROUND   Returns a number rounded to the desired multiple

MULTINOMIAL   Returns the multinomial of a set of numbers

ODD   Rounds a number up to the nearest odd integer

PI   Returns the value of pi

PRODUCT   Multiplies its arguments

QUOTIENT   Returns the integer portion of a division

RADIANS   Converts degrees to radians

RAND   Returns a random number between 0 and 1

RANDBETWEEN   Returns a random number between the numbers you specify

ROMAN   Converts an arabic numeral to roman, as text

ROUNDDOWN   Rounds a number down, toward zero

ROUNDUP   Rounds a number up, away from zero

SERIESSUM   Returns the sum of a power series based on the formula

SIGN   Returns the sign of a number

SIN   Returns the sine of the given angle

SINH   Returns the hyperbolic sine of a number

SQRT   Returns a positive square root

SQRTPI   Returns the square root of (number * pi)

SUBTOTAL   Returns a subtotal in a list or database

SUMIF   Adds the cells specified by a given criteria

SUMPRODUCT   Returns the sum of the products of corresponding array components

SUMSQ   Returns the sum of the squares of the arguments

SUMX2MY2   Returns the sum of the difference of squares of corresponding values in two arrays

SUMX2PY2   Returns the sum of the sum of squares of corresponding values in two arrays

SUMXMY2   Returns the sum of squares of differences of corresponding values in two arrays

TAN   Returns the tangent of a number

TANH   Returns the hyperbolic tangent of a number

TRUNC   Truncates a number to an integer

Statistical

AVEDEV   Returns the average of the absolute deviations of data points from their mean

AVERAGEA   Returns the average of its arguments, including numbers, text, and logical values

BETADIST   Returns the cumulative beta probability density function

BETAINV   Returns the inverse of the cumulative beta probability density function

BINOMDIST   Returns the individual term binomial distribution probability

CHIDIST   Returns the one-tailed probability of the chi-squared distribution

CHIINV   Returns the inverse of the one-tailed probability of the chi-squared distribution

CHITEST   Returns the test for independence

CONFIDENCE   Returns the confidence interval for a population mean

CORREL   Returns the correlation coefficient between two data sets

COUNTA   Counts how many values are in the list of arguments

COVAR   Returns covariance, the average of the products of paired deviations

CRITBINOM   Returns the smallest value for which the cumulative binomial distribution is less than or equal to a                               criterion value

DEVSQ   Returns the sum of squares of deviations

EXPONDIST   Returns the exponential distribution

FDIST   Returns the F probability distribution

FINV   Returns the inverse of the F probability distribution

FISHER   Returns the Fisher transformation

FISHERINV   Returns the inverse of the Fisher transformation

FORECAST   Returns a value along a linear trend

FREQUENCY   Returns a frequency distribution as a vertical array

FTEST   Returns the result of an F-test

GAMMADIST   Returns the gamma distribution

GAMMAINV   Returns the inverse of the gamma cumulative distribution

GAMMALN   Returns the natural logarithm of the gamma function, Γ(x)

GEOMEAN   Returns the geometric mean

GROWTH   Returns values along an exponential trend

HARMEAN   Returns the harmonic mean

HYPGEOMDIST   Returns the hypergeometric distribution

INTERCEPT   Returns the intercept of the linear regression line

KURT   Returns the kurtosis of a data set

LARGE   Returns the k-th largest value in a data set

LINEST   Returns the parameters of a linear trend

LOGEST   Returns the parameters of an exponential trend

LOGINV   Returns the inverse of the lognormal distribution

LOGNORMDIST   Returns the cumulative lognormal distribution

MAX   Returns the maximum value in a list of arguments

MAXA   Returns the maximum value in a list of arguments, including numbers, text, and logical values

MEDIAN   Returns the median of the given numbers

MIN   Returns the minimum value in a list of arguments

MINA   Returns the smallest value in a list of arguments, including numbers, text, and logical values

MODE   Returns the most common value in a data set

NEGBINOMDIST   Returns the negative binomial distribution

NORMDIST   Returns the normal cumulative distribution

NORMINV   Returns the inverse of the normal cumulative distribution

NORMSDIST   Returns the standard normal cumulative distribution

NORMSINV   Returns the inverse of the standard normal cumulative distribution

PEARSON   Returns the Pearson product moment correlation coefficient

PERCENTILE   Returns the k-th percentile of values in a range

PERCENTRANK   Returns the percentage rank of a value in a data set

PERMUT   Returns the number of permutations for a given number of objects

POISSON   Returns the Poisson distribution

PROB   Returns the probability that values in a range are between two limits

QUARTILE   Returns the quartile of a data set

RANK   Returns the rank of a number in a list of numbers

RSQ   Returns the square of the Pearson product moment correlation coefficient

SKEW   Returns the skewness of a distribution

SLOPE   Returns the slope of the linear regression line

SMALL   Returns the k-th smallest value in a data set

STANDARDIZE   Returns a normalized value

STDEV   Estimates standard deviation based on a sample

STDEVA   Estimates standard deviation based on a sample, including numbers, text, and logical values

STDEVP   Calculates standard deviation based on the entire population

STDEVPA   Calculates standard deviation based on the entire population, including numbers, text,     and logical                                        values

STEYX   Returns the standard error of the predicted y-value for each x in the regression

TDIST   Returns the Student's t-distribution

TINV   Returns the inverse of the Student's t-distribution

TREND   Returns values along a linear trend

TRIMMEAN   Returns the mean of the interior of a data set

TTEST   Returns the probability associated with a Student's t-test

VARA   Estimates variance based on a sample, including numbers, text, and logical values

VARP   Calculates variance based on the entire population

VARPA   Calculates variance based on the entire population, including numbers, text, and logical values

WEIBULL   Returns the Weibull distribution

ZTEST   Returns the two-tailed P-value of a z-test

Text and Data

ASC   Changes full-width (double-byte) English letters or katakana within a character string to half-        width (single-byte) characters

BAHTTEXT   Converts a number to text, using the ß (baht) currency format

CHAR   Returns the character specified by the code number

CLEAN   Removes all nonprintable characters from text

CODE   Returns a numeric code for the first character in a text string

CONCATENATE   Joins several text items into one text item

DOLLAR   Converts a number to text, using the $ (dollar) currency format

EXACT   Checks to see if two text values are identical

FIND   Finds one text value within another (case-sensitive)

FIXED   Formats a number as text with a fixed number of decimals

JIS   Changes half-width (single-byte) English letters or katakana within a character string to full-width                   (double-byte) characters

LEFT   Returns the leftmost characters from a text value

LOWER   Converts text to lowercase

MID   Returns a specific number of characters from a text string starting at the position you specify

PHONETIC   Extracts the phonetic (furigana) characters from a text string

REPLACE   Replaces characters within text

REPT   Repeats text a given number of times

RIGHT   Returns the rightmost characters from a text value

SEARCH   Finds one text value within another (not case-sensitive)

SUBSTITUTE   Substitutes new text for old text in a text string

T   Converts its arguments to text

TEXT   Formats a number and converts it to text

TRIM   Removes spaces from text

UPPER   Converts text to uppercase

VALUE   Converts a text argument to a number