Fundamental of Computers
& Information Technology
Unit-III
Software: - A computer
can not do anything on its own. It must be instructed to do a desired job.
Hence it is necessary to specify a sequence of instructions that a computer
must perform to solve a problem. Such a sequence of instructions written in a
language that can be understood by a computer is called a computer program. It
is the program that controls the activity of processing by the computer and the
computer perform precisely what the program wants it to do. When a computer is
using a particular program, we say it is running or execution that program. The
term software refers to the set of computer program, procedures, and associated
documents (flowcharts, manuals, etc) that describe the programs and how they
are to be precise, software means a collection of programs whose objective is
to enhance the capabilities of the hardware.
A software package is a
group of programs that solve a specific type of job. For example, a
word-processing package may contain program for text editing, text formatting,
A graphics, spelling checking, etc. Thus a multipurpose computer system has
several software packages one each for every type of job it can perform.
Relationship Between
Hardware and Software: -In order for a computer to produce useful output,
the hardware and software must work together. Nothing useful can be done with
the computer hardware on its own and software cannot be utilized without
supporting hardware.
To take on analogy, a
cassettes player and the cassettes purchased form market are hardware. However,
the songs recorded on the cassettes are its software. To listen to a particular
song, first of all that song has to be recorded on one of the cassettes, which
should then be mounted on the cassette player and played. Similarly, to get a
particular job done by a computer, the relevant software should be loaded in
the hardware before processing starts. The following important points regarding
the relationship between hardware and software are brought out by this analogy.
1. Both hardware and
software are necessary for a computer to do useful job. Both are complementary
to each other.
2. The same hardware can be
loaded with different software to make a computer system perform different
types of just as different songs can be played using the same cassette player.
3. Except for upgrades (like increasing
the main memory and hard disk capacities, or adding speakers, modems, etc)
hardware is normally a one-time expense whereas software is a continuing expense.
Just as we buy new cassettes for the newly released songs or for songs whose
cassettes we do not have, similarly one busy new software to be run on the same
hardware as and when need arises or funds become available.
Types of Software: - A wide variety
of computer software is available today. Although the range of software
available is vast and varied, most software can be divided in to two major
categories;
- System software, and
- Application software
These two types of software
along with a few examples of each type are described below.
System Software: - System software is a set
of one or more programs designed to control the operation and extend the
processing capability of a computer system. In general, a computer’s system
software performs one or more of the following functions;
1.supports the
development of other application software.
2.supports the
execution of other application software.
3.monitors the
effective use of various hardware resources such as CPU, memory, peripherals,
etc.
4.communicates
with and controls the operation of peripheral devices such as printer, disk,
tape etc.
Thus system software makes
the operation of a computer system more effective and efficient .it helps the
hardware components work together and provides support for the development and
execution of application soft ware (program). The programs included in a system
software package are called system programs and the programmers who prepare
system software are referred to as system programmers.
System software offers several
advantages and conveniences to application programmers and computer users in
general. Good system software allows application packages to be run on the
computer with less time and effort. Without system software, application
packages could not be run on the computer system. Thus, system software is an
indispensable part of a total computer system. A computer without some kind of
system soft ware would be very ineffective and most likely impossible to
operate. The production of system software is a complex task that requires
extensive knowledge and considerable specialized training in computer science.
System programmers are highly trained computer professionals. Because of its
technical complexity, system software is normally developed and distributed by
the computer manufacturers. The customer who buys or leases a computer system
would usually receive, in addition to the hardware, some software needed for
the effective operation of his/her computer.
Some of the most commonly
known types of system software are operation system, programming language
translators, utility programs, Assemblers, Compliers, Interpreter and
performance monitoring software and communication software. They are briefly
described below.
Operating Systems; - Every computer
has an operating system software that takes care of the effective and efficient
utilization of all the hardware and soft ware components of the computer system
. It is responsible for performing basic tasks such as recognizing input from
the keyboard, sending output to the display screen, keeping tracks of files and
directories on the hard disk, and controlling peripheral device such as
printers and modems. In addition, the operating system ensures that different
programs executing at the same time do not interfere with each other.
Function of Operating System: - The main
function provided by most operating system of today are as follows:
- Process Management: - A process is a
program in execution. During execution, a process needs certain resources
such as CPU time, memory space, files and I/O devices. At a particular
instance of time, a computer system normally consists of a collection of
processes. The process management module of an operating system takes care
of the creation and deletion of processes, scheduling of various system
resources to the different processes requesting them, and providing
mechanism for synchronization and communication among processes.
- Memory Management:- To execute a
program, it must be loaded, together with the data it accesses, in the main
memory. To improve CPU utilization and to provide better response time to
its users, a computer system normally keeps several programs in main memory.
The memory management module of an operating system takes care of the
allocation and deallocation of memory space to the various programs in
need of this resource.
- File Management:- All computer systems
are used for storage, retrieval and sharing of information. A computer
normally stores such information in units called files. Processes can read
information from files and can create new files for storing newly
generated information. Information stored in files is made persistent by
storing them on a secondary storage media such as a magnetic disks. The
file management module of an operating system takes care of file-related
activities such as organization, storing, retrieval, naming, sharing and
protection of files.
- Device Management:- A computer system
normally consists of several I/O devices such as terminal, printer, disk
and tape. The device management module of an operating system takes care
of controlling all the computer’s I/O devices. It keeps track of I/O
requests from processes, issues commands to the I/O devices, and ensures
correct data transmission to/from an I.O device. It also provides an interface
between the devices and the rest of the system that is simple and easy to
use.
- Security:- Computer system
often store large amounts of information, some of which is highly
sensitive and valuable to their users. Users can trust the system and rely
on it only if the various resources and information of a computer system
are protected against destruction and unauthorized access.
- Command Interpretation:- A user
communicates with the operating system, for using the various system
resources, via a set of commands provided by the operating system. The
operating system also provides a simple language, known as command
language or job control language(JCL), using which a user can put several
commands together from the commands set to describe the resource requirements
of the job. The command interpretation module of an operating system takes
care of interpreting user commands, supplied individually or in the form
of command language, and directing the system resources to handle the request.
Types of Operating System:- The operating
system has evolved immensely (hugely) from its primitive (ancient) days to the present digital era.
Batch:-This type of
operating system was one of the first to evolve. Batch processing operating
system allowed only one program to run at a time. These kinds of operating system
can still be found on some mainframe computers running batches of jobs. Batch
processing operating system works on a series of programs that are held in a
queue. The operating system is responsible for scheduling the jobs according to
priority and the resources required. For example: this operating system would
be best suited for a company wishing to automate their payrolls. List of
employees will be entered, their monthly salary will be calculated, and corresponding
pay slips would be printed. Batch processing is useful for this purpose since
these procedures are repeated for every employee each month.
Multiprogramming:- Multiprogramming refers to the situation in
which a single CPU divides its time between more than one job. It is term given
to a system that may have several processes in "states of execution"
at the same time. Multiprogramming increases CPU utilization by organizing jobs
when CPU becomes less idle, waiting for input, output or data transfer
operations to be completed. More is the
number of programs competing for resources, better will be resource
utilization. In this manner multiprogramming increases the over all performance
of the system.
Multiprocessing:- Multiprocessing refers to simultaneous execution of two or more
processes by a multiple, processor computer system. Additional processors are
added to the system to enhance
the throughput. The additional processor can be an Input-Output Processor (IOP)
or
a CPU. Generally, multiprocessing system is defined by a system having more
than one CPU.
Device Drivers & Utility
Programs:-Utility programs are a set of programs that help
users in system maintenance tasks and in performing tasks of routine nature.
Certain utility programs are usually bundled along with the operating system.
Some utility programs are available for free and as per requirement, other
utilities can be purchased from third party commercial vendors. Some of the
tasks commonly performed by utility programs include the following.
1.Formatting hard disks or floppy disks.
2.Reorganizing files on a
hard disk to conserve storage space.
3.Taking backup of files
stored on hard disk on to a tape or floppy disk.
4.Searching a particular
file from a directory of hundreds of files.
5.Checking the amount of
available memory.
6. Checking the amount
available storage space on hard disk.
7.Reducing the file size for
more efficient transmission over a data communication link
8.Sorting of the records
stored in a file in a particular order based on some key field (s).
9.Scanning the system for
computer viruses
Introduction & Features of
DOS –Any operating system which runs from the
hard disk drive is termed as Disk Operating System ( D.O.S ). This also refers
to the specific family of disk operating system which is also known as MS-DOS
or Microsoft disk operating system. Anything which commands and controls the
computer’s hardware and its peripheral devices with control over the program
and its functionality is known as the operating system. This operating system
which runs through the hard disk is known as a disk operating system. For the
very first time, It was made and introduced for IBM by Microsoft which was
known as IBM PC DOS in the year 1981.
List of DOS
List of DOS made from 1981 – 1998 are as follows:
IBM PC DOS – 1981
DR-DOS – 1988
ROM-DOS – 1989
PTS-DOS – 1993
FREE-DOS – 1998
It was rebranded version under the title IBM PC DOS, both
of which came in the year 1981. DOS other than Microsoft in the market are:
Apple DOS
Apple Pro DOS
Atari DOS
Commodore DOS
TRSDOS
Amiga DOS
It was the first operating system used by IBM-compatible
computers. It was first available in two different versions that were typically
the same, but marketed and controlled under two different brands. MS-DOS was
the framework behind Windows operating systems until Windows XP.
“PC-DOS” was the version of dos developed by IBM and sold
to the first IBM-compatible manufactured computers. “MS-DOS” was the version of
dos that Microsoft bought the rights and patents, and was merged with the first
versions of Windows. Command line was used by DOS, or text-based interface,
that typed command allowed by the users. By giving simple instructions such as
pwd (print working directory) and cd(change directory), the user can open files
or run the program or browse the files on the hard drive. Written originally by
Tim Patterson (considered as the father of DOS) and owned by Seattle Computer
Products, Microsoft takes over 86-DOS for $75,000, licensed the same
software and released it with an IBM PC as MS-DOS 1.0 in 1982 with IBM and
Microsoft joint venture.
Windows-Microsoft
Windows, commonly referred to as Windows, is a group of
several proprietary graphical operating system families,
all of which are developed and marketed by Microsoft.
Each family caters to a certain sector of the computing industry. Active
Microsoft Windows families include Windows NT and Windows IoT;
these may encompass subfamilies, (e.g. Windows Server or Windows Embedded Compact) (Windows CE). Defunct
Microsoft Windows families include Windows 9x, Windows Mobile and Windows Phone.
Microsoft introduced an operating
environment named Windows on November 20,
1985, as a graphical operating
system shell for MS-DOS in
response to the growing interest in graphical user interfaces (GUIs).[5] Microsoft Windows came to dominate the
world's personal
computer (PC) market with over 90% market share,
overtaking Mac
OS, which had been introduced in 1984. Apple came
to see Windows as an unfair encroachment on their innovation in GUI development
as implemented on products such as the Lisa and Macintosh (eventually
settled in court in Microsoft's favor in 1993). On PCs, Windows is still the
most popular operating system. However, in 2014, Microsoft admitted losing the
majority of the overall operating system market to Android,[6] because of the massive growth in sales of Android smartphones.
In 2014, the number of Windows devices sold was less than 25% that of Android
devices sold. This comparison, however, may not be fully relevant, as the two
operating systems traditionally target different platforms. Still, numbers for
server use of Windows (that are comparable to competitors) show one third
market share, similar to that for end user use.
Programming
Languages:- A computer, being an electronic device, cannot understand
instructions if provided in a general language. Therefore, a special language
is used to provide instructions to a computer system. This language is known as
computer programming language. It consists of a set of symbols and characters,
words and grammar rules that permit the user to construct instructions in the
format that can be understood and acted upon by the computer system. A major
goal of computer scientists is to develop computer system which can accept
instructions in normal human language – known as Natural Language Processor.
Generations of Programming
Languages:-
The term 'generation' of computer languages is used to
categorize the generic enhancements in various computer languages. It shows the
step-by-step evolution of programming languages. Each generation indicates
significant progress towards making computers easier to use. Computer languages
by generation are classified as follows:
First Generation (late 1940s)
e.g. machine language
Second Generation (early 1950s)
e.g. assembly language
Third Generation (late 1950s through 1970s)
e.g. high level language
Fourth Generation (late 1970 onwords)
includes a whole
range of query languages and other tools.
Classification of Programming
Languages
Computer programming languages can be classified into two
major categories:
Low Level
High Level
Low Level Languages
The languages
which use only primitive operations of the computer are known as low level
languages. In these languages, programs are written by means of the memory and
registers available on the computer. As we all know that the architecture of
computer differs from one machine to another, so for each type of computer
there is a separate low level programming language. In the other words,
Programs written in one low level language of one machine can't be ported on
any other machine due to architectural changes. Because of this, low level
languages are known as machine dependent languages. Examples are Machine
Language and Assembly Language.
Machine Language:- In machine language programs, the
computation is based on binary numbers. All the instructions including
operations, registers, data and memory locations are given in there binary
equivalent.
The machine
directly understands this language by virtue of its circuitry design so these
programs are directly executable on the computer without any translations This
makes the program execution very fast. Machine languages are also known as
first generation languages. A typical low level instruction consists
essentially of two parts:
u An Operation Part : Specifies
operation to be performed by the
computer,
also known as Opcode.
u An Address Part : Specifies
location of the data on which operation
is
to be performed.
Writing programs
in machine language is a tedious task since it is very difficult
for humans to remember binary codes of all the operations. The number of bits
in
the operation part determines the number of possible unique instructions that
can
be framed for a computer to execute. The number of bits in the address part
determines the number of directly addressable, unique storage locations in
internal memory of the computer.
Advantages
Machine language makes most efficient use of computer system
resources like storage, registers, etc. The instructions of a machine language
program are directly executable so there is no need of translators. Machine
language instructions can be used to manipulate the individual bits in a
computer system with a very high execution speed due to direct manipulation of
memory and registers.
Drawbacks
Machine languages are machine dependent
and, therefore, programs are not portable from one computer to the other.
Programming in machine language usually results in poor programmer
productivity. Machine languages require programmers to control the use of each
register in the computer's Arithmetic Logic Unit and computer storage locations
must be addressed directly, not symbolically. Machine language requires a high
level of programming skill which increases programmer training costs. Programs
written in machine language are more error prone and difficult to debug because
it is very difficult to remember all binary equivalent of register, opcode,
memory locations, etc. Program size is comparatively very big due to non-use of
reusable codes and use of very basic operations to do a complex computation.
Assembly Language:- Assembly languages are also known as
second generation languages. These languages substitute alphabetic or numeric
symbols for the binary codes of machine language. That is, we can use mnemonics
for all opcodes, registers and for the memory locations which provide us the more
readable form of the program. These languages also provide us with a facility
to write reusable code in the form of macros. Macros has two parts, one is
macro name and the other is macro body which contains the line of instructions.
A macro can be called at any point of the program by its name to use the
instructions given in the macro repetitively.
These languages
require a translator known as 'Assembler' for translating the program code
written in assembly language to machine language. Because computer can
interpret only the machine code instructions, once the translation is completed
the program can be executed. A typical assembly language instruction consists
of four components:
u A name or label field
u An operation code
(Opcode)
u An operand
u A comment field
(separated by ; (semicolon) from the executable part of the instruction).
A name or label
field is optional. It is used to mark a place in a program to which computer
control can be transferred. An operation code specifies to the control unit
what processing tasks to perform and the operand field identifies the location
of data item in primary memory. The comment field enables a programmer to write
relevant notes and thereby improve the program documentation. This field is
optional. In assembly language, symbols are used rather than absolute
addresses, to represent memory locations, e.g. hexadecimal value can be used to
represent the memory location of the data in a statement. For example, 2AH for
hexadecimal where 2A represents some memory location. Similarly BX and CX can
be used to represent B register and C register of the computer's ALU
respectively. Mnemonics are used for operation code, i.e. short abbreviations
that help programmers remember what the codes represent.
Advantages
Assembly languages provide optimal use of computer resources like
registers and memory because of direct use of these resources within the
programs. Assembly language is easier to use than machine language because
there is no need to remember or calculate the binary equivalents for opcode and
registers. An assembler is useful for detecting programming errors. Assembly
language encourages modular programming which provides the facility of reusable
code, using macro.
Drawbacks
Assembly language programs are not directly executable due to the
need of translation. Also, these languages are machine dependent and,
therefore, not portable from one machine to another. Programming in assembly
language requires a high level of programming skills and knowledge of computer
architecture of the particular machine.
High Level Language:- All high level languages are
procedure-oriented languages and are intended to be machine independent.
Programs are written in statements akin to English language, a great
advancement over mnemonics of assembly language. That is, the high level
languages use natural language like structures. These languages require
translators (compilers and interpreters) for translating high level language
programs into machine language programs for execution. The programs written in
a high level language can be ported on
any computer, that is why known they are known as machine independent. The
early high level languages come in third generation of languages, e.g. COBOL,
FORTRAN, PASCAL, BASIC, APL, etc.
These languages
enable the programmer to write instructions using English words and familiar
mathematical symbols which makes it easier for programmers to concentrate on
the logic of problem-solving rather than technical details of the computer. It
makes the programs more readable too.
4GL:- Fourth generation languages (4GLs) are a
class of software designed to simplify the task of developing a new application
by making the user interface similar to natural languages. These are very easy
to use languages. Some 4GLs are designed to improve the productivity of
programming professionals while others are designed to be used directly by the
end user.
4GLs are
designed more for specification of what tasks to be accomplished as compared to third generation procedural
languages which focus on how to solve a problem. These languages are developed
for the purpose of making database management more efficient and is also known
as database management systems. Database Management System (DBMS) is a concept
to construct, organize and manipulate a large set of data in a best possible
way.
Example:
u Suppose personal details
of all employees are stored in a file
called Employee Master File. It is required to display all the information
about a particular employee, say, David.
u To accomplish the task
using procedural (third generation) language, the programmer would have to
write a series of instructions as follows:
Step 1 Get a record
from the employee master file.
Step 2 Check if the
record belongs to employee name "David".
Step 3 If the answer
for step 2 is "Yes", display details.
Step 4 Otherwise, go
to step 1.
u In 4GLs the task could be
accomplished by giving a single instruction as follows:
Display
all for employee name =
"David" from employee master file.
Many fourth
generation languages either incorporate a query language or support a standard
query language like SQL, which can be used to interact with the database.
e.g.: SQL
statement for the above illustration will be:
[Select * from employee_master where
emp_name = "David".]
Note * means all the fields
of record.
Advantages
u Easy to use; little or no
computer knowledge is required.
u Machine independent.
u Enhanced programming
productivity.
u Ease of modification and
maintenance of data.
u Good documentation.
Disadvantages
u 4GL programs are less
efficient from the computer resource utilization point of view.
u Programmers become less
skilled over a period of time.
u Security standards are difficult to enforce in 4GL environment.
Programming Languages: A programming
language is a primary interface of a programmer with a computer. A programming
language includes a series of commands, which are used in development of
software. Programming language is further divided into three categories:
Machine Language, Assembly Language and High-level Language. Hundreds of
programming languages have been developed since the invention of a computer
system.
Language Translators: - Language
translators are system software that transform the instructions prepared by
programmers using convenient programming languages into a from that can be
interpreted and executed by a computer system. Along with every programming
language developed, a language translator was also developed, which accepted
the programs written in a programming language and executed them by
transforming them into a form suitable for execution. Depending on the
programming language used, language translators are divided into three major
categories: Assemblers, Compilers and Interpreter.
Assemblers:- Compared to all the types of programming
languages, assembly language is closest to the machine code. The assembly
language program must be translated into machine code by a separate program
called an assembler. The assembler program recognizes the character strings
that make up the symbolic names of the various machine operations and
substitutes the required machine code for each instruction. In short, an
assembler converts the assembly codes into machine codes, making the assembly
program ready for execution.
Compliers:- A compiler is a
type of language translator that translates a program code into machine language.
The programs written in any programming language needs to be converted to
binary form. Therefore, in order to execute the programs, a programmer needs to
compile the written programs. As a system program, a compiler translates source
code into object code. For examples:
Borland C++ compiler and Microsoft VC++ compiler
Interpreters:- An interpreter
is another type of language translator, which analyses and executes the source
code in line-by-line manner, without looking at the entire program. In other
words, an interpreter translates a statement in a program and executes the
statements immediately, that is, before translating the next source language
statement. The advantage of interpreters is that they can execute a program
suddenly. Compilers requires some time
before an executable program is made because it looks at the whole source code.
However, programs produced by compilers run much faster than the same programs
executed by the interpreter. For examples: GW-BASIC Interpreter and LISP
Interpreter
Application Software: - Application software is a set of one or more programs designed to
solve a specific problem or do a specific task. For example an application
software for payroll processing produces pay slips as the major output and an
application software for processing examination results produces mark sheets as
the major output along with some other statistical reports. Similarly a program
written by a scientist to solve his/her particular research problem is also an
application software .the programs included in an application software package
are called application programs and the programmers who prepare application
software are referred to as application programmers.
There are literally millions of
application software available for a wide range of applications ranging from
simple applications such as word processing inventory management preparation of
tax returns ,banking hospital administration ,insurance, publishing, to complex
scientific and engineering applications such as weather forecasting ,space
shuttle launching oil and natural gas exploration ,design of complex structures
like aircrafts, ships bridges, sky rise buildings, etc. With so many
applications available, it is not possible to categorize them all and to cover
them here. Hence just to have a feel of what application soft ware dose, some
of the most only known application
software are briefly described below.
Word Processing Software:-Word processing is a term that describes the use of computers to create
,edit ,view ,format, store, retrieve and print documents (written material such
as letters, reports, books, etc).A word-processing software is an application
software that enables the user to do all these on a computer system .the need
to create documents is so common is every walk of life ,whether it is at work
,at school, or at home ,that word-processing soft ware is the most commonly
used application software.
Spreadsheet Software: -A Spreadsheet software is a numeric data analysis tool that allows you
to create a kind of computerized ledger .A manual ledger is a book having rows
and columns that accountants use for keeping a record of financial transactions
and for preparing financial statements. Accountants use the manual ledger with
pencil, erasure and hand calculator to prepare financial statements. This is a
tedious task and often takes a long time due to several iteration of formula
calculations to come out with an acceptable and satisfactory financial
statement. A spreadsheet software offers considerable ease of performing such
tasks by automating all arithmetic calculations and making it much easier to
change certain numeric values and immediately seeing the effect of these
changes across the worksheet (ledger). With spreadsheet software in place, we
are no longer confined to using pencils, erasers , and hand calculator for
dealing with any task that requires numeric data analysis of the nature
mentioned above.
Presentation Graphics:- A graphics
software enables us to use a computer system for creating , editing , viewing ,
storing, retrieving and printing designs, drawings, pictures , graphs and
anything else that can be drawn in the traditional manner.
Database Management Software:-This application software is designed to take advantage of the
tremendous capability of computer system in storing organizing and selectively
retrieving large volumes of data efficiently A database is a collection of
related data stored and treated as a unit for information retrieval purposes.
It is important here to note the difference
between data and information. Data is stored in a database whereas information
is retrieved from a database. That is data is input to any data processing
system and information is its output .in other, data is the raw material for a
data processing system and information is the processed data.
A database concept can be
best illustrated with an example. For example , a school’s student database
might contain the name, sex, date of birth, current address, permanent address,
parent’s occupation , marks scored in various subjects in each class already
passed , and current occupation for all the students who are either currently
enrolled or have already graduated from the school similarly ,an individual’s
address database might contain the names , addresses, and telephone numbers of
all his/her friends and business contacts. The data of one student in the
student database or one person in the address database is known as a record.
A database software is a set
of one or more programs that enables users to create a database , maintain it
(add, delete and update its records ), organize its data in desired fashion
(for example, sort its records alphabetically name-wise),and to selectively
retrieve useful information from it (for
example , get the telephone number of the person named kashyap rana from the
address database , or get the names of all currently enrolled students from the
student database whose birthday fall today ).
Database software is widely
used today by both large and small organizations to maintain employee data,
customer data, assets data , accounting data, etc. Even individuals find the
database software very useful for maintaining data such as list of addresses
and telephone numbers of their friends and relatives, list of household goods
and other valuables, list of various types of savings in different banks ,etc
.
Desktop publishing- Desktop publishing (DTP) is the creation of documents
using page layout software on
a personal ("desktop") computer.
It was first used almost exclusively for print publications, but now it also
assists in the creation of various forms of online content. Desktop publishing
software can generate layouts and produce typographic-quality text and images
comparable to traditional typography and printing.
Desktop publishing is also the main reference for digital typography. This
technology allows individuals, businesses, and other organizations to self-publish
a wide variety of content, from menus to magazines to
books, without the expense of commercial printing.
Communication-In a data
communication network, the task of network designers is to select and
coordinate the network components so that the necessary data is moved to the
right place, at the right time, with a minimum of errors, and at the lowest
possible cost. A number of communication processors are used by network
designers to achieve these goals. The functions of some of the commonly used
communication processors are described below:
Educational Graphics&
multimedia- Graphics "
are visual images
or designs on some surface, such as a wall, canvas,
screen, paper, or
stone to inform, illustrate,
or entertain. In contemporary usage, it includes a pictorial representation of
data, as in c manufacture, in typesetting and the graphic arts, and in
educational and recreational software.
Images that are generated by a computer are called computer graphics.
Example- -are photographs, drawings, lineart, graphs, diagrams, typography, numbers, symbols, geometric designs, maps, engineering
drawings, or other images. Graphics often
combine text, illustration,
and color. Graphic design may
consist of the deliberate selection, creation, or arrangement of typography alone,
as in a brochure, flyer, poster, web site, or book without any other element.
Clarity or effective communication may be the objective, association with other
cultural elements may be sought, or merely, the creation of a distinctive
style.
Graphics can be functional or artistic. The latter can be
a recorded version, such as a photograph,
or interpretation by a scientist to highlight essential features, or an artist,
in which case the distinction with imaginary graphics may become blurred. It
can also be used for architecture.
Business Accounting- Business Accounting is the process of gathering and analyzing
financial information on business activity, recording transactions, and
producing financial statements.
Business accounting is important for a variety of reasons.
Keeping tabs on all of your assets, liabilities, inventory, and other records
can help you secure investors, protect your assets from theft, and find ways to
grow your company and take it to the next level. Primary duties of small
business accounting include bookkeeping, preparing and filing tax returns, and drafting financial reports.
Through business accounting, you can better manage
your finances to make informed financial decisions
for your company. Many small business owners take on accounting themselves in
the early stages to save money. If you’re in the same boat, it’s essential you
have a firm grasp on business accounting
MIS
– MIS can be defined as the systematic or organized
way of providing informational support to the managerial functions of an
organization. The system utilizes computer hardware, software, manual
procedure, models for analysis, planning control, and decision-making and a
database. In other words: “An MIS is an automated system which presents
information, both internal and external to the business that aids in making a
specific set of routine decisions.” There are a few aspects of the above
definition that warrant closer scrutiny.
- MIS is an
organized or planned effort and not the result of some sporadic attempts.
- Meaningful
and interpreted information is the output of the system.
- The
primary function of the MIS is to provide information.
- MIS is a
facilitating or supporting system to aid managerial functions and not
merely help operational tasks, that is, the MIS provides information that
assists managers at different levels in the organization.
- MIS is
formed from a number of components, including hardware, software, manual
procedures, models, and a database.
- MIS is a
system of users and machines; the users are as important to the system as
are the machines.
The field of MIS is the study of information and its
impact on the individual, the organization, and society. Quite often, when we
think about information systems we think of computers. Although computers are
at the heart of today’s information system, a number of important social,
organizational, behavioral, and ethical issues also surround the study of
information systems. An appropriate analogy is the field of medicine. Medicine
and its branches revolve around the human body and its various parts and
functions. Similarly, today’s information system revolves around a business and
its various components, such as people, products, and procedures. MIS is an
interdisciplinary field; many other fields of study influence it. Areas that
continue to influence the filed of MIS include.
- Computer
Science: Theories and Methods of computation, efficient data storage and
access, and their impact on information.
- Political
Science: The political impact and uses of information, both within and
outside the organization.
- Psychology:
Cognitive models of human reasoning and behaviour as they relate to
information.
- Operations
Research: Scientific models that enhance decision making and make use of
information to solve complex problems.
- Linguistics:
Languages and human communications and their influence on the creation
and use of information.
- Sociology:
Principles governing society as it related to shaping information
policies and principles.
- Organization
theory and behavior: The nature and characteristics of organization and
their effect on the way human beings use information to make decisions.
MIS is a system that creates, processes, stores and
generates information within and outside an organization. A system is a
collection of parts that work together to achieve a common goal. The primary
goal of MIS is to support organizational decision making, though it has many
other uses, such as designing and developing new products, ensuring the quality
of goods and services, preventing theft and pilferage, and so on.
Gaming and ERP Software –Tackling compliance challenges, maintaining
sovereignty, and improving your operations are among the top priorities for
tribal gaming facilities. Your tribe’s members rely on your gaming facility and
related activities for not only employment for community but revenue for
infrastructure, healthcare, housing, education, and more.
Managing your facility
requires visibility, control, and efficiency as you work to orchestrate a mix
of applications used to manage a broad range of revenue streams. The right
Enterprise Resource Planning solution can provide transparency, control, and
visibility across your operations.
Improve the management
of your administrative and financial departments, and gain tools to increase
the success of purchasing and inventory with tribal gaming accounting software
integrated with your casino management software. Improve efficiency and
productivity in finance and administrative roles, as well as significantly
reduce costs.
Cloud-based ERP can be
integrated with other necessary applications to offer a complete solution that
streamlines and enhances processes, improves efficiency, and saves money.
Computer coding system– Computer Codes:-- Numeric data is not the only form of data
handled by a computer. We often requires to process alphanumeric data also. An
alphanumeric data is a string of symbols, where a symbol may be one of the
letters A, B, C,…….Z, or one of the digits 0,1,2,…..9, or a special character,
such as + - * / , . () = (space or blank) etc. An alphabetic data consists of
only the letters A, B,C,……Z, and blank character. Similarly, numeric data
consists of only the digits 0,1,2,….and 9. However, the bits 0 and 1 must
represent any data internally. Hence, computers use binary coding schemes to
represent data internally.
BCD Numbers: Binary Coded
Decimal (BCD) code is one of the early computer codes. The idea of this coding
scheme is to convert each digit of a decimal number into its binary equivalent
instead of converting the entire decimal value into a binary number. This makes
the conversion process easier.
|
Decimal Digits |
BCD Equivalent |
|
0 |
0000 |
|
1 |
0001 |
|
2 |
0010 |
|
3 |
0011 |
|
4 |
0100 |
|
5 |
0101 |
|
6 |
0110 |
|
7 |
0111 |
|
8 |
1000 |
|
9 |
1001 |
Figure shows BCD equivalent of each decimal
digit. Since 8 and 9 require 4 bits, all decimal digits are represented in BCD
by 4 bits. As you, know that 4210 is equal to 1010102. However, converting 4210 into BCD
produces the following result:
4210=0100 0010 or 01000010 in BCD
Note that each decimal digit
is independently converted to a 4-bit binary number, and hence, the conversion
process is very easy. Also note that when four bits are used, altogether 16 (24)
combinations are possible. However, from figure you can see that only the first
10 of these combinations are used to represent decimal digits. The remaining
six arrangements (1010, 1011, 1100, 1101, 1110 and 1111) have decimal values
from 10 to 15. These arrangements are not used in BCD coding. That is 1010 does
not represent 1010 in BCD. Instead,
1010= 0001 0000 or
00010000 in BCD
4-bit BCD coding system can be used to represent only
decimal numbers because four bits are insufficient to represent the various
characters used by a computer. Hence, instead of using four bits with only 16
possible characters, computer designers commonly use six bits to represent
characters in BCD code. In 6-bit BCD code, the four BCD numeric place positions
are retained but two additional zone positions are added. With six bits, it is
possible to represent 64(26) different characters. This is
sufficient to code the decimal digits (10), alphabetic letters(26), and other
special characters(28).
EBCDIC:- The major
problem with BCD code is that it can represent only 64(26) different
characters. This is not sufficient for providing decimal numbers (10),
lowercase (small) letters (26), uppercase (capital) letters (26), and a large
number of other special characters (28+). Hence, BCD code was extended from a
6-bit code to an 8-bit code. The added two bits are used as additional zone
bits, expanding the zone to four bits. The resulting code is called the
Extended Binary-Coded Decimal Interchange Code (EBCDIC). In this code, it is
possible to represent 256(28) different characters, instead of 64 (26).
In addition to the various characters, this also allows a large variety of
printable characters and several non-printable control characters. The control
characters are used to control such activities as printer vertical spacing,
movement of cursor on terminal screen etc. All of the 256 combinations have not
yet been assigned characters. Hence, the code can still grow, as new
requirements develop. Developed by IBM, EBCDIC code is used in most IBM models,
and in many other computers.
ASCII Codes: Another widely
used computer code is the American Standard Code for Information
Interchange(ASCII). Several American computer manufactures have adopted ASCII as
their computer’s internal code. This code is popular in data communications, is
used almost exclusively to represent data internally in microcomputers and is
frequently found in larger computers produced by some vendors.
American National Standards Institute(ANSI) published
ASCII standard in 1963. However, the standard lacked lowercase letters and ANSI
subsequently revised ASCII in 1967. Later revisions in 1968, 1977 and finally
in 1986 brought it in its present form. Today, ASCII is one of the most popular
and widely supported character-encoding standards.
ASCII is of two types- ASCII-7 and ASCII-8. ASCII-7 is a
7-bit code that can represent 128(27) different characters.
Computers using 8-bit byte and 7-bit ASCII either set the 8th bit
(leftmost bit) of each byte as zero or use it as a parity bit.
ASCII-8 is an extended version of ASCII-7. It is an 8-bit
code that can represent 256(28) different characters. The additional bit is
added to the left of the 7th bit(leftmost bit) of ASCII-7 codes.
ASCII-7 uses only 7 bits whereas all the 8 bits are used in ASCII-8. Hence, the
codes of first 128 characters (symbols) are identical in ASCII-7 and ASCII-8.
ISCII -Indian Script Code for Information Interchange (ISCII) is a coding scheme for representing various writing
systems of India. It encodes the main Indic scripts and a Roman transliteration.
Assamese, Bengal
(Bangla), Devanagari, Gujarati, Gurmukhi, Kannada, Malayalam, Oriya, Tamil, and Telugu. ISCII does not encode the
writing systems of India based on Persian, but its writing system
switching codes nonetheless provide for Kashmiri, Sindhi, Urdu, Persian, Pashto and Arabic. The Persian-based writing
systems were subsequently encoded in the PASCII encoding.
ISCII has not been widely used outside certain government
institutions, although a variant without the ATR mechanism was used on classic Mac OS,[1] and it has now been rendered largely obsolete by Unicode. Unicode uses a separate
block for each Indic writing system, and largely preserves the ISCII layout
within each block.
Number system of computer-We know that a computer stores
data internally in a format that is not easily readable by human beings. Every
computer stores numbers, letters and other special characters in codes form.
Therefore, you have to understand number system before codes. Basically, there
are two types of number system.
1) Non-Positional Number Systems:- In early days,
human beings counted on fingers. When counting beyond ten fingers, they used
stones, pebbles, or sticks to indicate values. This method of counting uses
known as non-positional number system. In this system, we have symbols such as
I for 1, II for 2, III for 3, IIII for 4, IIIII for 5 etc. Each symbol
represents the same value regardless of its position in a number, and to find
the value of a number, one has to count the number of symbols present in the
number. Since it is very difficult to perform arithmetic with such a number
system, positional number systems were developed.
2) Positional Number System:- In a positional
number system, there are only a few symbols called digits. These symbols represent
different values, depending on the position they occupy in a number. The value
of each digit in such a number is determined by three considerations:
a) The digit itself,
b) The position of
the digit in the number, and
c) The base of the
number system(where base is defined as the total number of digits available in
the number system).
In our day-to-day life, we use
decimal number system. In this system, base is equal to 10 because there are
altogether ten symbols or digits (0, 1, 2, 3, 4, 5, 6, 7, 8, and 9). You know
that in decimal number system, successive positions to the left of the decimal
point represent units, tens, hundreds, thousands, etc. However, notice that
each position represents a specific power of the base (10). For example,
decimal number 2586(written as 258610) consists of digit 6 in unit’s
position, 8 in tens position, 5 in hundreds positions, and 2 in thousands
positions, and its value can be written as:
(2*103)+(5*102)+(8*101)+(6*100)=2000+500+80+6=2586
The principles that apply to decimal number system, also
apply to any other positional number system. It is important to keep track of
only the base of the number system in which we are working. The value of the
base in all positional number systems suggests the following characteristics:
- The value of
the base determines the total number of different symbols or digits
available in the number system. The first of these choices is always zero.
The maximum value of a
single digit is always equal to one less than the value of the bases
Binary- Binary number system is like
decimal number system, except that the base is 2, instead of 10. You can use
only two symbols or digits (0 and 1) in this number system. Note that the
largest single digits are 1(one less than the base). Each position in a binary
number represents a power of the base (2). Hence, in this system, the rightmost
positions is units (20) position, the second position from the right
is 2’s (21) and so on. Therefore, decimal equivalent of binary
number 10101(written as 101012) is:
(1*24)+(0*23)+(1*22)+(0*21)+(1*20)=16+0+4+0+1=21
Hence, we can write
101012=2110
The
short form of “binary digit” is bit. Hence, a bit in computer terminology means
either a 0 or 1. An n-bit number is a binary number consisting of ‘n’ bits. All
3-bit numbers along with their decimal equivalent is shown in table.
|
Binary |
Decimal Equivalent |
|
000 |
0 |
|
001 |
1 |
|
010 |
2 |
|
011 |
3 |
|
100 |
4 |
|
101 |
5 |
|
110 |
6 |
|
111 |
7 |
Remember that we have only
two digits, 0 and 1, in binary number system and hence, binary equivalent of decimal
number 2 has to be stated as 10(read as one, zero). Another important point to
note is that with 3 bits (positions), only 8(23) different patterns
of 0s and 1s are possible, as shown in table. In fact, any decimal number in
the range 0 to 2n-1 can be represented in binary form as an n-bit
number. Every computer stores numbers, letters, and other special characters in
binary form. There are several occasions when computer professionals need to
know the raw data contained in a computer’s memory. A commonly used way of
doing this is to print memory contents on a printer. This printout is called a
memory dump. Memory dumps, which are in binary numbers, would have many pages
of 0s and 1s. Working with these numbers would be very difficult and error
prone for computer professional. Hence, two number systems- octal and
hexadecimal are often used as shortcut notations for binary.
Octal- In octal
number system, the base is 8. Hence, there are only eight symbols or digits:
0,1,2,3,4,5,6 and 7. The largest single digit is 7(one less than the base 8).
Each positions in an octal number represents a power of the base (8).
Therefore, decimal equivalent of octal number 2057(written as 20578)
is:
(2*83)+(0*82)+(5*81)+(7*80)=1024+0+40+7=1071
Hence, 20578=107110
Observe that there are only
8 digits in octal number system, 3 bits( 23=8) are sufficient to
represent any octal number in binary.
Decimal-The decimal numeral system (also called base-ten positional
numeral system, and occasionally called denary
is the standard system for denoting integer and non-integer numbers.
It is the extension to non-integer numbers of the Hindu–Arabic numeral
system[2] The way of denoting numbers in the decimal system is often
referred to as decimal notation.[3]
A decimal numeral (also often just decimal or,
less correctly, decimal number), refers generally to the notation
of a number in the decimal numeral system. Decimals may sometimes be identified
by a decimal
separator (usually "." or ","
as in 25.9703 or 3,1415).[4][5] Decimal may also refer specifically to the digits
after the decimal separator, such as in "3.14 is the approximation of π to two decimals".
The numbers that may be represented in the decimal system
are the decimal
fractions. That is, fractions of the form a/10n, where a is
an integer, and n is
a non-negative
integer.
The decimal system has been extended to infinite
decimals for representing any real number, by using an infinite sequence of
digits after the decimal separator (see decimal representation). In this context, the decimal numerals with a finite number of
non-zero digits after the decimal separator are sometimes called terminating
decimals. A repeating decimal is
an infinite decimal that, after some place, repeats indefinitely the same
sequence of digits (e.g., 5.123144144144144... = 5.123144).[6] An infinite decimal represents a rational number if and only if it is a repeating decimal or has a finite
number of non-zero digits.
Hexadecimal their conversion-In hexadecimal
number system, the base in 16. Hence, there are 16 symbols or digits. The first
10 digits are the same digits of decimal number system- 0, 1, 2, 3, 4, 5, 6, 7,
8, and 9. The remaining six digits are denoted by the largest single digit is F
or 15(one less than the base 16). Each position in hexadecimal number system
represents a power of the base (16). Therefore, decimal equivalent of
hexadecimal number 1AF (written as 1AF16) is:
(1*162)+(A*161)+(F*160)=(1*256)+(10*16)+(15*1)=256+160+15=431
Hence, 1AF16=43110
Observe that since there are
only 16 digits in hexadecimal number system, 4 bits (24=16) are
sufficient to represent any hexadecimal number in binary
Inter Conversion: Numbers
expressed in decimal number system are much more meaningful to us, than are
numbers expressed in any other number system. However, you can represent any
number in one number system in any other number system. Because the input and
final output values are to be in decimal, computer professionals are often
required to convert numbers in other number system to decimal and vice-versa.
Many methods or techniques can be used to convert numbers from one base to
another.
Converting
to Decimal from Another Base:-- The following three steps are used to convert to
a base 10 value from any other number system:
Step 1: Determine the column
value of each digit(this depends on the position of the digit and the base of
the number system).
Step 2: Multiply the
obtained column values by the digits in the corresponding columns.
Step 3: Sum the products
calculated in step 2. The total is the equivalent value in decimal.
For Example: 110012=?10
Step 1: Determine Column Values
Column Number Column
Value
1
20 = 1
2
21 = 2
3
22 = 4
4
23 = 8
5
24 = 16
Step 2: Multiply column
values by corresponding column digits
16 8 4 2 1
*1 *1 *0 *0 *1
Step 3: Sum the products
16+8+0+0+1=25
Converting from a Base 10 to
a new base(Division-Remainder Technique):
The following four steps are
used to convert a number from base 10 to a new base:
Step 1: Divide the decimal
number to be converted by the value of the new base.
Step 2: Record the remainder
from step 1 as the rightmost digit(least significant digit) of the new base
number.
Step 3: Divide the quotient
of the previous divide by the new base.
Step 4: Record the remainder
from step 3 as the nest digit, (to the left) of the new base number.
For Example: 2510
= ?2
Steps 1 & 2: 25/2= 12
and remainder 1
Steps 3 & 4: 12/2= 6 and
remainder 0
Steps 3 & 4: 6/2= 3 and
remainder 0
Steps 3 & 4: 3/2= 1 and
remainder 1
Steps 3 & 4: ½= 0 and
remainder 1
Hence, 2510=
110012
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