पीरियड्स रुक रुक के आने का कारण- Period Ruk Ruk Ke Aane Ke Karan

Being a modern-day kid you must have used, seen, or read about computers. This is because they are an integral part of our everyday existence. Be it school, banks, shops, railway stations, hospital or your own home, computers are present everywhere, making our work easier and faster for us. As they are such integral parts of our lives, we must know what they are and how they function. Let us start with defining the term computer formally.

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The literal meaning of computer is a device that can calculate. However, modern computers can do a lot more than calculate. Computer is an electronic device that receives input, stores or processes the input as per user instructions and provides output in desired format.

Input-Process-Output Model

Computer input is called data and the output obtained after processing it, based on user’s instructions is called information. Raw facts and figures which can be processed using arithmetic and logical operations to obtain information are called data.

The processes that can be applied to data are of two types −

• Arithmetic operations − Examples include calculations like addition, subtraction, differentials, square root, etc.

• Logical operations − Examples include comparison operations like greater than, less than, equal to, opposite, etc.

The corresponding figure for an actual computer looks something like this −

The basic parts of a computer are as follows −

• Input Unit − Devices like keyboard and mouse that are used to input data and instructions to the computer are called input unit.

• Output Unit − Devices like printer and visual display unit that are used to provide information to the user in desired format are called output unit.

• Control Unit − As the name suggests, this unit controls all the functions of the computer. All devices or parts of computer interact through the control unit.

• Arithmetic Logic Unit − This is the brain of the computer where all arithmetic operations and logical operations take place.

• Memory − All input data, instructions and data interim to the processes are stored in the memory. Memory is of two types – primary memory and secondary memory. Primary memory resides within the CPU whereas secondary memory is external to it.

Control unit, arithmetic logic unit and memory are together called the central processing unit or CPU. Computer devices like keyboard, mouse, printer, etc. that we can see and touch are the hardware components of a computer. The set of instructions or programs that make the computer function using these hardware parts are called software. We cannot see or touch software. Both hardware and software are necessary for working of a computer.

Characteristics of Computer

To understand why computers are such an important part of our lives, let us look at some of its characteristics −

• Speed − Typically, a computer can carry out 3-4 million instructions per second.

• Accuracy − Computers exhibit a very high degree of accuracy. Errors that may occur are usually due to inaccurate data, wrong instructions or bug in chips – all human errors.

• Reliability − Computers can carry out same type of work repeatedly without throwing up errors due to tiredness or boredom, which are very common among humans.

• Versatility − Computers can carry out a wide range of work from data entry and ticket booking to complex mathematical calculations and continuous astronomical observations. If you can input the necessary data with correct instructions, computer will do the processing.

• Storage Capacity − Computers can store a very large amount of data at a fraction of cost of traditional storage of files. Also, data is safe from normal wear and tear associated with paper.

Advantages of Using Computer

Now that we know the characteristics of computers, we can see the advantages that computers offer−

• Computers can do the same task repetitively with same accuracy.

• Computers do not get tired or bored.

• Computers can take up routine tasks while releasing human resource for more intelligent functions.

Disadvantages of Using Computer

Despite so many advantages, computers have some disadvantages of their own −

• Computers have no intelligence; they follow the instructions blindly without considering the outcome.

• Regular electric supply is necessary to make computers work, which could prove difficult everywhere especially in developing nations.

Booting

Starting a computer or a computer-embedded device is called booting. Booting takes place in two steps −

• Switching on power supply
• Loading operating system into computer’s main memory
• Keeping all applications in a state of readiness in case needed by the user

The first program or set of instructions that run when the computer is switched on is called BIOS or Basic Input Output System. BIOS is a firmware, i.e. a piece of software permanently programmed into the hardware.

If a system is already running but needs to be restarted, it is called rebooting. Rebooting may be required if a software or hardware has been installed or system is unusually slow.

There are two types of booting −

• Cold Booting − When the system is started by switching on the power supply it is called cold booting. The next step in cold booting is loading of BIOS.

• Warm Booting − When the system is already running and needs to be restarted or rebooted, it is called warm booting. Warm booting is faster than cold booting because BIOS is not reloaded.

Computer – Operating System

The Operating System is a program with the following features −

• An operating system is a program that acts as an interface between the software and the computer hardware.

• It is an integrated set of specialized programs used to manage overall resources and operations of the computer.

• It is a specialized software that controls and monitors the execution of all other programs that reside in the computer, including application programs and other system software.

 

Objectives of Operating System

The objectives of the operating system are −

• To make the computer system convenient to use in an efficient manner.

• To hide the details of the hardware resources from the users.

• To provide users a convenient interface to use the computer system.

• To act as an intermediary between the hardware and its users, making it easier for the users to access and use other resources.

• To manage the resources of a computer system.

• To keep track of who is using which resource, granting resource requests, and mediating conflicting requests from different programs and users.

• To provide efficient and fair sharing of resources among users and programs.

Characteristics of Operating System

Here is a list of some of the most prominent characteristic features of Operating Systems −

• Memory Management − Keeps track of the primary memory, i.e. what part of it is in use by whom, what part is not in use, etc. and allocates the memory when a process or program requests it.

• Processor Management − Allocates the processor (CPU) to a process and deallocates the processor when it is no longer required.

• Device Management − Keeps track of all the devices. This is also called I/O controller that decides which process gets the device, when, and for how much time.

• File Management − Allocates and de-allocates the resources and decides who gets the resources.

• Security − Prevents unauthorized access to programs and data by means of passwords and other similar techniques.

• Job Accounting − Keeps track of time and resources used by various jobs and/or users.

• Control Over System Performance − Records delays between the request for a service and from the system.

• Interaction with the Operators − Interaction may take place via the console of the computer in the form of instructions. The Operating System acknowledges the same, does the corresponding action, and informs the operation by a display screen.

• Error-detecting Aids − Production of dumps, traces, error messages, and other debugging and error-detecting methods.

• Coordination Between Other Software and Users − Coordination and assignment of compilers, interpreters, assemblers, and other software to the various users of the computer systems.

 

Digital Drawing

Digital drawing is the act of using a computer to draw. Common methods of digital drawing include a stylus or finger on a touchscreen device, stylus- or finger-to-touchpad, or in some cases, a mouse. There are many digital art programs and devices.

Drawing is a form of visual art in which an artist uses instruments to mark paper or other two-dimensional surface. Drawing instruments include graphite pencils, pen and ink, various kinds of paints, inked brushes, coloured pencils, crayons, charcoal, chalk, pastels, erasers, markers, styluses, and metals (such as silverpoint).

The basic tools are a drawing board or table, pencil sharpener and eraser, and for ink drawing, blotting paper. Other tools used are circle compass, ruler, and set square. Fixative is used to prevent pencil and crayon marks from smudging. Drafting tape is used to secure paper to drawing surface, and also to mask an area to keep it free of accidental marks, such as sprayed or spattered materials and washes. An easel or slanted table is used to keep the drawing surface in a suitable position, which is generally more horizontal than the position used in painting.

The medium is the means by which ink, pigment or colour are delivered onto the drawing surface. Most drawing media are either dry (e.g. graphite, charcoal, pastels, Conte, silverpoint), or use a fluid solvent or carrier (marker, pen and ink). Watercolour pencils can be used dry like ordinary pencils, then moistened with a wet brush to get various painterly effects. Very rarely, artists have drawn with (usually decoded) invisible ink. Metal point drawing usually employs either of two metals: silver or lead. More rarely used are gold, platinum, copper, brass, bronze, and tin point.

Paper comes in a variety of different sizes and qualities, ranging from newspaper grade up to high quality and relatively expensive paper sold as individual sheets. Papers vary in texture, hue, acidity, and strength when wet. Smooth paper is good for rendering fine detail, but a more “toothy” paper holds the drawing material better. Thus a coarser material is useful for producing deeper contrast.

Newsprint and typing paper may be useful for practice and rough sketches. Tracing paper is used to experiment over a half-finished drawing, and to transfer a design from one sheet to another. Cartridge paper is the basic type of drawing paper sold in pads. Bristol board and even heavier acid-free boards, frequently with smooth finishes, are used for drawing fine detail and do not distort when wet media (ink, washes) are applied. Vellum is extremely smooth and suitable for very fine detail. Cold pressed watercolour paper may be favoured for ink drawing due to its texture.

There are several categories of drawing, including figure drawing, cartooning, doodling, and freehand. There are also many drawing methods, such as line drawing, stippling, shading, the surrealist method of entropic graphomania (in which dots are made at the sites of impurities in a blank sheet of paper, and lines are then made between the dots), and tracing (drawing on a translucent paper, such as tracing paper, around the outline of preexisting shapes that show through the paper).

A quick, unrefined drawing may be called a sketch.

A drawing instrument releases a small amount of material onto a surface, leaving a visible mark. The most common support for drawing is paper, although other materials, such as cardboard, wood, plastic, leather, canvas, and board, have been used.

In addition to its more artistic forms, drawing is frequently used in commercial illustration, animation, architecture, engineering, and technical drawing. A quick, freehand drawing, usually not intended as a finished work, is sometimes called a sketch. An artist who practices or works in technical drawing may be called a drafter, draftsman, or draughtsman.

Functions of OS

As you know, operating system is responsible for functioning of the computer system. To do that it carries out these three broad categories of activities −

• Essential functions − Ensures optimum and effective utilization of resources

• Monitoring functions − Monitors and collects information related to system performance

• Service functions − Provides services to users

Let us look at some of the most important functions associated with these activities.

Processor management

Managing a computer’s CPU to ensure its optimum utilization is called processor management. Managing processor basically involves allocating processor time to the tasks that need to be completed. This is called job scheduling. Jobs must be scheduled in such a way that −

• There is maximum utilization of CPU
• Turnaround time, i.e. time required to complete each job, is minimum
• Waiting time is minimum
• Each job gets the fastest possible response time
• Maximum throughput is achieved, where throughput is the average time taken to complete each task

There are two methods of job scheduling done by operating systems −

• Preemptive scheduling
• Non-Preemptive scheduling

Preemptive Scheduling

In this type of scheduling, next job to be done by the processor can be scheduled before the current job completes. If a job of higher priority comes up, the processor can be forced to release the current job and take up the next job. There are two scheduling techniques that use pre-emptive scheduling −

• Round robin scheduling − A small unit of time called time slice is defined and each program gets only one time slice at a time. If it is not completed during that time, it must join the job queue at the end and wait till all programs have got one time slice. The advantage here is that all programs get equal opportunity. The downside is that if a program completes execution before the time slice is over, CPU is idle for the rest of the duration.

• Response ratio scheduling − Response ratio is defined as

  ElapsedTimeExecutiontimereceivedElapsedTimeExecutiontimereceived

  A job with shorter response time gets higher priority. So a larger program may have to wait even if it was requested earlier than the shorter program. This improves throughput of the CPU.

Non-preemptive Scheduling

In this type of scheduling, job scheduling decisions are taken only after the current job completes. A job is never interrupted to give precedence to higher priority jobs. Scheduling techniques that use non-preemptive scheduling are −

• First come first serve scheduling − This is the simplest technique where the first program to throw up a request is completed first.

• Shortest job next scheduling − Here the job that needs least amount of time for execution is scheduled next.

• Deadline scheduling − The job with the earliest deadline is scheduled for execution next.

Memory Management

Process of regulating computer memory and using optimization techniques to enhance overall system performance is called memory management. Memory space is very important in modern computing environment, so memory management is an important role of operating systems.

As you know, computers have two types of memory – primary and secondary. Primary memory is fast but expensive and secondary memory is cheap but slower. OS has to strike a balance between the two to ensure that system performance is not hurt due to very less primary memory or system costs do not shoot up due to too much primary memory.

Input and output data, user instructions and data interim to program execution need to be stored, accessed and retrieved efficiently for high system performance. Once a program request is accepted, OS allocates it primary and secondary storage areas as per requirement. Once execution is completed, the memory space allocated to it is freed. OS uses many storage management techniques to keep a track of all storage spaces that are allocated or free.

Contiguous Storage Allocation

This is the simplest storage space allocation technique where contiguous memory locations are assigned to each program. OS has to estimate the amount of memory required for the complete process before allocation.

Non-contiguous Storage Allocation

As the name suggests, program and associated data need not be stored in contiguous locations. The program is divided into smaller components and each component is stored in a separate location. A table keeps a record of where each component of the program is stored. When the processor needs to access any component, OS provides access using this allocation table.

In a real-life scenario primary memory space might not be sufficient to store the whole program. In that case, OS takes the help of Virtual Storagetechnique, where program is physically stored in secondary memory but appears to be stored in primary memory. This introduces a miniscule time lag in accessing the program components. There are two approaches to virtual storages −

• Program paging − A program is broken down into fixed size pageand stored in the secondary memory. The pages are given logical address or virtual address from 0 to n. A page table maps the logical addresses to the physical addresses, which is used to retrieve the pages when required.

• Program segmentation − A program is broken down into logical units called segments, assigned logical address from 0 to n and stored in secondary memory. A segment table is used to load segments from secondary memory to primary memory.

Operating systems typically use a combination of page and program segmentation to optimize memory usage. A large program segment may be broken into pages or more than one small segments may be stored as a single page.

File Management

Data and information is stored on computers in form of files. Managing file system to enable users to keep their data safely and correctly is an important function of operating systems. Managing file systems by OS is called file management. File management is required to provide tools for these file related activities −

• Creating new files for storing data
• Updating
• Sharing
• Securing data through passwords and encryption
• Recovery in case of system failure

Device Management

The process of implementation, operation and maintenance of a device by operating system is called device management. Operating system uses a utility software called device driver as interface to the device.

When many processes access the devices or request access to the devices, the OS manages the devices in a way that efficiently shares the devices among all processes. Processes access devices through system call interface, a programming interface provided by the OS.

 

Types of OS

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As computers and computing technologies have evolved over the years, so have their usage across many fields. To meet growing requirements more and more customized software have flooded the market. As every software needs operating system to function, operating systems have also evolved over the years to meet growing demand on their techniques and capabilities. Here we discuss some common types of OS based on their working techniques and some popularly used OS as well.

GUI OS

GUI is the acronym for Graphical User Interface. An operating system that presents an interface comprising graphics and icons is called a GUI OS. GUI OS is very easy to navigate and use as users need not remember commands to be given to accomplish each task. Examples of GUI OS includes Windows, macOS, Ubuntu, etc.

Time Sharing OS

Operating systems that schedule tasks for efficient processor use are called time sharing OS. Time sharing, or multitasking, is used by operating systems when multiple users located at different terminals need processor time to complete their tasks. Many scheduling techniques like round robin scheduling and shortest job next scheduling are used by time sharing OS.

Real Time OS

An operating system that guarantees to process live events or data and deliver the results within a stipulated span of time is called a real time OS. It may be single tasking or multitasking.

Distributed OS

An operating system that manages many computers but presents an interface of single computer to the user is called distributed OS. Such type of OS is required when computational requirements cannot be met by a single computer and more systems have to be used. User interaction is restricted to a single system; it’s the OS that distributed work to multiple systems and then presents the consolidated output as if one computer has worked on the problem at hand.

Popular Operating Systems

Initially computers had no operating systems. Every program needed full hardware specifications to run correctly as processor, memory and device management had to be done by the programs themselves. However, as sophisticated hardware and more complex application programs developed, operating systems became essential. As personal computers became popular among individuals and small businesses, demand for standard operating system grew. Let us look at some of the currently popular operating systems −

• Windows − Windows is a GUI operating system first developed by Microsoft in 1985. The latest version of Windows is Windows 10. Windows is used by almost 88% of PCs and laptops globally.

• Linux − Linux is an open source operating system mostly used by mainframes an supercomputers. Being open source means that its code is available for free and anyone can develop a new OS based on it.

• BOSS − Bharat Operating System Solutions is an Indian distribution of Linux based on Debian, an OS. It is localized to enable use of local Indian languages. BOSS consists of −

• Linux kernel
• Office application suite BharteeyaOO
• Web browser
• Email service Thunderbird
• Chat application Pidgim
• File sharing applications
• Multimedia applications

Mobile OS

An operating system for smartphones, tablets and other mobile devices is called mobile OS. Some of the most popular OS for mobile devices includes−

• Android − This Linux-based OS by Google is the most popular mobile OS currently. Almost 85% of mobile devices use it.

• Windows Phone 7 − It is the latest mobile OS developed by Microsoft.

• Apple iOS − This mobile OS is an OS developed by Apple exclusively for its own mobile devices like iPhone, iPad, etc.

• Blackberry OS − This is the OS used by all blackberry mobile devices like smartphones and playbooks.

 

Utility Software

Utility Software

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Application software that assist OS in carrying out certain specialized tasks are called utility software. Let us look some of the most popular utility software.

Antivirus

A virus can be defined as a malicious program that attaches itself to a host program and makes multiple copies of itself, slowing down, corrupting or destroying the system. A software that assists the OS in providing virus free environment to the users is called antivirus. An anti-virus scans the system for any virus and if detected, gets rid of it by deleting or isolating it. It can detect many types of virus like boot virus, Trojan, worm, spyware, etc.

When any external storage device like USB drive is attached to the system, anti-virus software scans it and gives an alert if a virus is detected. You can set up your system for periodic scans or scan whenever you feel the need. A combination of both the techniques is advisable to keep your system virus free.

File management tools

As you know, file management is an important function of operating systems as all data and instructions are stored in the computer in form of files. Utility software providing regular file management tasks like browse, search, update, preview, etc. are called file management tools. Windows Explorer in Windows OS, Google desktop, Directory Opus, Double Commander, etc. are examples of such tools.

Compression tools

Storage space is always at a premium in computer systems. So operating systems are always looking at ways to minimize amount of storage space taken by files. Compression tools are utilities that assist operating systems in shortening files so that they take less space. After compression files are stored in a different format and cannot be read or edited directly. It needs to be uncompressed before it can be accessed for further use. Some of the popular compression tools are WinRAR, PeaZip, The Unarchiver, etc.

Disk Cleanup

Disk cleanup tools assist users in freeing up disk space. The software scans hard disks to find files that are no longer used and frees up space by deleting them.

Disk Defragmenter

Disk defragmenter is a disk management utility that increases file access speeds by rearranging fragmented files on contiguous locations. Large files are broken down into fragments and may be stores in non-contiguouslocations if contiguous ones are not available. When such files are accessed by the user, access speed is slow due to fragmentation. Disk defragmenter utility scans the hard disk and tries to assemble file fragments so that they may be stored in contiguous locations.

Backup

Backup utility enables backing up of files, folders, databases or complete disks. Backups are taken so that data may be restored in case of data loss. Backup is a service provided by all operating systems. In stand-alone systems backup may be taken in the same or different drive. In case of networked systems backup may be done on backup servers.

 

Number System

Number System

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The technique to represent and work with numbers is called number system. Decimal number system is the most common number system. Other popular number systems include binary number system, octal number system, hexadecimal number system, etc.

Decimal Number System

Decimal number system is a base 10 number system having 10 digits from 0 to 9. This means that any numerical quantity can be represented using these 10 digits. Decimal number system is also a positional value system. This means that the value of digits will depend on its position. Let us take an example to understand this.

Say we have three numbers – 734, 971 and 207. The value of 7 in all three numbers is different−

• In 734, value of 7 is 7 hundreds or 700 or 7 × 100 or 7 × 10²
• In 971, value of 7 is 7 tens or 70 or 7 × 10 or 7 × 10¹
• In 207, value 0f 7 is 7 units or 7 or 7 × 1 or 7 × 10⁰

The weightage of each position can be represented as follows −

In digital systems, instructions are given through electric signals; variation is done by varying the voltage of the signal. Having 10 different voltages to implement decimal number system in digital equipment is difficult. So, many number systems that are easier to implement digitally have been developed. Let’s look at them in detail.

Binary Number System

The easiest way to vary instructions through electric signals is two-state system – on and off. On is represented as 1 and off as 0, though 0 is not actually no signal but signal at a lower voltage. The number system having just these two digits – 0 and 1 – is called binary number system.

Each binary digit is also called a bit. Binary number system is also positional value system, where each digit has a value expressed in powers of 2, as displayed here.

In any binary number, the rightmost digit is called least significant bit (LSB) and leftmost digit is called most significant bit (MSB).

And decimal equivalent of this number is sum of product of each digit with its positional value.

11010₂ = 1×2⁴ + 1×2³ + 0×2² + 1×2¹ + 0×2⁰

= 16 + 8 + 0 + 2 + 0

= 26₁₀

Computer memory is measured in terms of how many bits it can store. Here is a chart for memory capacity conversion.

• 1 byte (B) = 8 bits
• 1 Kilobytes (KB) = 1024 bytes
• 1 Megabyte (MB) = 1024 KB
• 1 Gigabyte (GB) = 1024 MB
• 1 Terabyte (TB) = 1024 GB
• 1 Exabyte (EB) = 1024 PB
• 1 Zettabyte = 1024 EB
• 1 Yottabyte (YB) = 1024 ZB

Octal Number System

Octal number system has eight digits – 0, 1, 2, 3, 4, 5, 6 and 7. Octal number system is also a positional value system with where each digit has its value expressed in powers of 8, as shown here −

Decimal equivalent of any octal number is sum of product of each digit with its positional value.

726₈ = 7×8² + 2×8¹ + 6×8⁰

= 448 + 16 + 6

= 470₁₀

Hexadecimal Number System

Octal number system has 16 symbols – 0 to 9 and A to F where A is equal to 10, B is equal to 11 and so on till F. Hexadecimal number system is also a positional value system with where each digit has its value expressed in powers of 16, as shown here −

Decimal equivalent of any hexadecimal number is sum of product of each digit with its positional value.

27FB₁₆ = 2×16³ + 7×16² + 15×16¹ + 10×16⁰

= 8192 + 1792 + 240 +10

= 10234₁₀

Number System Relationship

The following table depicts the relationship between decimal, binary, octal and hexadecimal number systems.

HEXADECIMAL	DECIMAL	OCTAL	BINARY
0	0	0	0000
1	1	1	0001
2	2	2	0010
3	3	3	0011
4	4	4	0100
5	5	5	0101
6	6	6	0110
7	7	7	0111
8	8	10	1000
9	9	11	1001
A	10	12	1010
B	11	13	1011
C	12	14	1100
D	13	15	1101
E	14	16	1110
F	15	17	1111

ASCII

Besides numerical data, computer must be able to handle alphabets, punctuation marks, mathematical operators, special symbols, etc. that form the complete character set of English language. The complete set of characters or symbols are called alphanumeric codes. The complete alphanumeric code typically includes −

• 26 upper case letters
• 26 lower case letters
• 10 digits
• 7 punctuation marks
• 20 to 40 special characters

Now a computer understands only numeric values, whatever the number system used. So all characters must have a numeric equivalent called the alphanumeric code. The most widely used alphanumeric code is American Standard Code for Information Interchange (ASCII). ASCII is a 7-bit code that has 128 (27) possible codes.

ISCII

ISCII stands for Indian Script Code for Information Interchange. IISCII was developed to support Indian languages on computer. Language supported by IISCI include Devanagari, Tamil, Bangla, Gujarati, Gurmukhi, Tamil, Telugu, etc. IISCI is mostly used by government departments and before it could catch on, a new universal encoding standard called Unicode was introduced.

Unicode

Unicode is an international coding system designed to be used with different language scripts. Each character or symbol is assigned a unique numeric value, largely within the framework of ASCII. Earlier, each script had its own encoding system, which could conflict with each other.

In contrast, this is what Unicode officially aims to do − Unicode provides a unique number for every character, no matter what the platform, no matter what the program, no matter what the language.

 

Number System Conversion

Number System Conversion

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As you know decimal, binary, octal and hexadecimal number systems are positional value number systems. To convert binary, octal and hexadecimal to decimal number, we just need to add the product of each digit with its positional value. Here we are going to learn other conversion among these number systems.

Decimal to Binary

Decimal numbers can be converted to binary by repeated division of the number by 2 while recording the remainder. Let’s take an example to see how this happens.

The remainders are to be read from bottom to top to obtain the binary equivalent.

43₁₀ = 101011₂

Decimal to Octal

Decimal numbers can be converted to octal by repeated division of the number by 8 while recording the remainder. Let’s take an example to see how this happens.

Reading the remainders from bottom to top,

473₁₀ = 731₈

Decimal to Hexadecimal

Decimal numbers can be converted to octal by repeated division of the number by 16 while recording the remainder. Let’s take an example to see how this happens.

Reading the remainders from bottom to top we get,

423₁₀ = 1A7₁₆

Binary to Octal and Vice Versa

To convert a binary number to octal number, these steps are followed −

• Starting from the least significant bit, make groups of three bits.

• If there are one or two bits less in making the groups, 0s can be added after the most significant bit

• Convert each group into its equivalent octal number

Let’s take an example to understand this.

1011001010₁₂ = 2625₈

To convert an octal number to binary, each octal digit is converted to its 3-bit binary equivalent according to this table.

Octal Digit	0	1	2	3	4	5	6	7
Binary Equivalent	000	001	010	011	100	101	110	111

 

54673₈ = 101100110111011₂

Binary to Hexadecimal

To convert a binary number to hexadecimal number, these steps are followed −

• Starting from the least significant bit, make groups of four bits.

• If there are one or two bits less in making the groups, 0s can be added after the most significant bit.

• Convert each group into its equivalent octal number.

Let’s take an example to understand this.

10110110101₂ = DB5₁₆

To convert an octal number to binary, each octal digit is converted to its 3-bit binary equivalent.

 

Hardware and Software

Hardware and Software

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The following table highlights the points that differentiate a hardware from a software.

Hardware	Software
It is the physical component of a computer system.	It is the programming language that makes hardware functional.
It has the permanent shape and structure, which cannot be modified.	It can be modified and reused, as it has no permanent shape and structure.
The external agents such as dust, mouse, insects, humidity, heat, etc. can affect the hardware (as it is tangible).	The external agents such as dust, mouse, insects, humidity, heat, etc. cannot affect (as it is not tangible).
It works with binary code (i.e., 1’s to 0’s) .	It functions with the help of high level language like COBOL, BASIC, JAVA, etc.
It takes in only machine language, i.e., lower level language.	It takes in higher level language, easily readable by a human being.
It is not affected by the computer bug or virus.	It is affected by the computer bug or virus.
It cannot be transferred from one place to other electronically.	It can transfer from one place to other electronically.
Duplicate copy of hardware cannot be created.	A user can create copies of a software as many as he wishes.

 

Analog and Digital

Analog and Digital

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The following table highlights the basic differences between analog and digital −

Analog	Digital
Its functions on physical analog system.	It functions on discrete numbers system.
The calculations in this system are primarily converted to equations and later converted into electrical signals.	The calculations in this system are converted into binary numbers (i.e., 1s and 0s).
To function, it requires physical analog.	To function, it requires discrete numbers.
It gives output in the form of ‘graph’.	It gives output in the form of discrete values.
Accuracy comparatively is less.	Accuracy is very high.
Performs at a low speed.	It performs at a very high speed.
Difficult to make changes, as it is less flexible.	It is highly flexible.
It has memory of low capacity.	It has memory of high capacity.
Its application is limited to certain applications.	Its application is applicable to a number of applications.
It is hardly applicable for the business applications.	It is very much suitable for the business applications.
It cannot process alpha-numeric data.	It can process alpha-numeric data.
It requires RF technology.	It requires IP networking.
Static channel assignment.	Automatic channels exist as required.