Number System

Number System

A number system is the set of symbols which is used to express quantities as the basic of counting, determining order comparing amount, performing calculation and representing values. It is set of characters and mathematical rules which are used to represent a number. In the simple word number system which talks about the numbers and their representation in different system. There are 4 types of Number systems. They are:-

1. Binary Number System

2. Decimal Number System

3. Octal Number System

4. Hexadecimal Number System

a) Binary Number system:- The number system having based 2 is called binary number system. It is the combination of zero and one (0 and 1). Data is represented in a computer system either one or zero.

Eg;- (01001)2

b) Decimal Number system:- The Number system having base 10 is called decimal number system. It can contain 10 different digits.

(0,1,2,3,4,5,6,7,8,9)

c) Octal Number System:- The number system having base 8 is called octal number system. It include 8 digit that is 0…..7. All the numbers are represented as the combination of 0….7 only such numbers are known as octal number system.

(0,1,2,3,4,5,6,7) Eg. (0754)8

d) Hexadecimal Number system:- The number system having base 16 is called Hexadecimal number system. It include 0 to 9 and A to F. It is the combination of 16 digits that’s it is known as hexadecimal number system.

(0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F) Eg. (758D)16

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Types of Computers

Types of Computers

On the Basis of work: - 

A. Analog Computer
B. Digital Computer
C. Hybrid computer

A.          Analog Computer

Analog Computer measure temperature, voltage, current and pressure.
1. Accuracy low.
2. Storage capacity low.
3. Analog computer cannot re program or if we need to be re programmed the where circuit and hardware part to be required with news to ones.
4. Low cost.

Analog Signal

B. Digital Computer

1. Digital comput er work with binary digits.
2. Accuracy high then analog.
3. Storage capacity high then analog.
4. These computers are totally fixable and can be reprogrammed.
5. Digital computer converts the data in two digits. 

Fig No 3:- Digital Signal 

C. Hybrid Computer

1. Combination of analog and digital called hybrid.
2. It can perform the function of both analog and digital.
3. In hybrid computer have analog signals to digital and digital to analog convertor. Hybrid computers are used in hospital, Jet planes, Industry etc. 

On The Basic Of Size.

Super Computer:- 

Super computer are very powerful, multiprocessor or most expensive computers. These types of computers are used in supermarket, shopping mall etc. 

1. More processers are connected in super computer.
2. Expensive and powerful then other computer.
3. Processing speed high.
4. Storage capacity high.

Mainframe computer:-

They are medium or large machine made of several units connected together. Mainframe computers are generally used in big organization and government department for large scale of data processing. It can calculate millions of bytes per second. E.g. IBM1401.

1. Processing speed low then super computer.
2. More people communicate at a same time.
3. Used to engineering, scientific research etc.

Mini Computer:-

They are like a small mainframe computers. They consist of few separate unit connected together, they can maintained and operated by people who are not computer expert. They can process information at they are four million bytes per second. They are not so powerful and generally they are used in small organization, government department etc. E.g. Prime9755.

1. The third generation called minicomputer.
2. Small then super and mainframe but large then micro computer.
3. Less powerful then super and mainframe but more powerful then micro.
4. Used to data processing, programming. 

Micro Computers:-

They are the smallest general purpose computers. They are some size of type-writer; they contain a small CPU which is known as microprocessor. These computers are also known as personal computers and they are used by single person at a time.

1. Using single micro processor.
2. Manufactured with 16bit or 32bit micro processor.
3. Micro computer also called Personal computer.
4. Used in many fields in business, Education, Desktop designing, programming.

Based on Brand

Computers are classified in terms of brands also. Many companies are involved in manufacturing of computers throughout the world. On the basic of brand computers are divided in to three types.
1. IMP PC
2. IMP compatible
3. Apple/Macintosh
1. IBM PC: - It stands for international Business Machine Personal Computer. It is one of the leading companies in the world which was established in 1924 in USA. The computer manufacturing by IBM Company is called IBM computers and the micro computers manufactories by IVM computers called IBM PC.

1. Manufactured by IBM Company.
2. IBM Company called IBM computer.
3. IBM is one of the leading companies in computer manufacturing.
4. Quite expensive than other computer. 

2. IMB compatible: - A computer that has the same functional characteristics and principle of IBM computer. They are called IVM compatible. All the software and program which run in IBM compatible. These computers are cheaper and most popular because there parts are easily available in the market.

1. IBM companies clone are called IBM compatible.
2. Less powerful then original IBM.

3. Apple and Macintosh:- The computer manufactured by apple company with different architecture is called Apple Computers. It was established in 1970 in USA. The Apple computers uses their own hardware and own software. These computers are some way different from IBM computer because the software used in apple computer does not run in IBM computer. The advanced version of apple computer is known as Macintosh.

1. Manufactured by Apple Company.
2.  Used for desktop designing.
3. They are original and quite expensive then IBM and IBM compatible

On the Basic Of Model:-

1. XT
2. AT
3. PS/2


1. XT : - (Extra/Extended Technology)

Those computers which have 8086, 8088 microprocessor they are called XT computers. They had processing speed is 4.77 Mhz. and they cannot run advanced version of software.

2. AT: - It stands for Advanced Technology computers and those computers which have 80286, 80386, 80486, 80586 microprocessor, they are known as AT computers. They have large capacity of memory so they can run advanced version of software and mostly they are used to perform mathematical operation.

3. PS/2: - It stands for Personal Computer; IBM company started manufacturing next model of computer in 1990, which is small in size and they portable because they can run any types of software, because there speed is more than other computers.

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Characteristics of Computer

Characteristics of Computer

Speed:- Computer can do even perform exceptionally complex computation that individual … .. not have the capacity to do. The velocity of the PC is measured in mili second, smaller scale second, Pico second and nano second. 

Capacity:- Computer framework can store an extraordinary measure of data in it. PCs have inbuilt and assistant memory. Any information or data put away in its memory can be recover at whatever time later on as per necessities of the client. The limit of memory measured in KB, MB, GB, TB and so forth. 

Exactness:- If the given direction is 100% precise the PC give the exact result, if the given guideline is not 100% precise than the PC can't give 100% precise result which is known as the precision of PC. 

Adaptability:- The PC is a flexible machine. PC can impart to other framework and receive a few mod, similar to sound, video, representation. The computers are exceptionally adaptable in its operation. It has an extensive variety of utilization. It implies they are utilized as a part of various region like training, therapeutic, showcasing, promotion business. 

Amortization:- Once we give the proper information and direction a PC can do the operation naturally as it is now modified to do as such. 

Determination:- A PC is fit for doing the required undertaking over and over without influencing its pace and exactness and also proficiency. 

Electronic: - Computer is an electronic machine. All the equipment segments are absolutely reliant on power, without power PC can't boot. 

Preferences of Computer 

1. Performance given by the PC is 100% precise and it is dependable the other machine and person. 

2. Comparing with person it is much quicker. 

3. Computer can be exceptionally valuable in doing rehashed jos which man can not to do. 

4. Computer is adaptable machine so it can do numerous sorts of occupation once at once. 

5. Computer can use in different field like, training, exploration, science and innovation. 

Detriments of Computer 

1. Computer is costly and is past the span of destitute individuals. 

2. Computer is electronic machine, so all the taking care of is much. 

3. Danger electric stun and other physical harms. 

4. Computer expansion relies on upon machine. Notwithstanding for exceptionally basic figuring individuals need them. 

5. Although it helps in speedier and less expensive correspondence, there is much risk of security spillage by outsider by which validation gets to be inquiries. 

All 

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Generation of the Computer

Generation of the Computer

   GENERATION TECHNIC USED PERIOD
1st                                    Vacuum tubes                 1943-1956
2nd                                    Transistor                       1956-1964
3rd                        IC (integrated circuit)               1964-1971
4th             VLSI (Very large scale Integration)    1972- Present
5th            BIO – CHIPS (Parallel Processor)      Under development

The history of computer development is often referred to in reference to the difference generation of computing devices each generation of computer is characteristics by a measured technological development that fundamentally changed the way computer operate, resulting in increasing smaller, cheaper, efficient and more reliable. In the simple word the generation of computer means it started two thousand years ago and it rich the current stage to pass the different steps these steps are known as generation of computer. Depending on the device used, system architecture, processing mode and language used in the computer are categorized in the following 5 generation.

1st   Generation Computer (Vacuum Tubes)(1943-1956)

The first generation computer used vacuum tubes and magnetic drums for memory. They are placed and they taking the entire room. They work very expensive to operate as well as they using a great deal of electricity and it generated a lot of hits. These computers support and used machine language to perform operation and they can perform only one task at a time. Input was based on punched card and output was displayed on printout.

Features of 1st generation 

1.  Vacuum tubes were used for electronic circuits. 
2.  Storage capacity was limited(1KB-4KB)
3.  Slow processing speed.(Mili Second)
4.  Large in size(1500 square feet)

2nd    Generation Computer (Transistor) (1956-1964)

Transistor replaced vacuum tubes in the second generation computer. It was invented in 1947 and they are used in after 1950. The transistor was far superior to vacuum tube they allowing computers to become smaller, faster and cheaper than first generation. They use high level language and low level language and they used punch card at a input and print out s a output.

Features of 2nd generation 

1. Transistors were use instead of vacuum tubes. 
2. Processing speed is faster than 1st generation computer. (Micro second)
3. Smaller in size. (51 squire feet)
4. The input and output devices were faster.

3rd  Generation Computer (IC chips) (1964-1971)

The development of the integrated circuit was the hall mark of the third generation computer. They used silicon chips which increase the speed and efficiency of the computer and they use\s keyboard and monitor as well as interface with operating system. They can run more than two programs at the same time.

Features of 3rd generation 

1. ICs were used in place of transistor. 
2. processing speed is faster than second generation computer.( Nano second) 
3. Mini computers were introduced during this generation. 
4. Storage capacity increased in Megabyte. 

4th Generation Computer (1972- Present) (Microprocessor)

The microprocessor use the small silicon chip and thousand of integrated circuit work, built on to single chip. They decrease their size, they are fit on to palm. The Intel 4004 chip is 1991 and in 1981 IBM introduced first computer as a microprocessor and in 1984 Apple Company introduce the Macintosh. They are more powerful, reliable computers and they support GUI application.

Features of 4th   generation

1. VLSI and microprocessor are used.
2. Processing speed is very high in Pico second.
3. Storage capacity was very high in GB.
4. Very smaller size. Various from a desktop, to Laptop.

5th Generation Computer (Under development) (AI- Artificial Intelligence) 

Fifth generation computer device is Artificial Intelligence nd they are still in developing phase. These uses some application such as voice recognition which are being used today the artificial Intelligence is the branch of computer science concerned with intelligence. Such application is used in fifth generation computer.

Features of 5th generation

1. High performance, multiprocessor system.
2. Easy human computer interface.
3. There will be used BIO (Basic Input Output) chips, ULSI (Ultra Large scale Integration.)
4. Computer will understand natural language.
5. They have artificial intelligence. 

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Software

Software

Software: Software is a collection of program as well as set of information, which are design and developed by software engineer by using programming language to perform of specific task as well as general task. For example: Ms. Office package, PageMaker, Tally, Corel Draw etc.

There are two types of software applications. They are:-

1-      System Software

2-      Application Software

1)      System Software:

System software is a kind of software which is responsible for managing and controlling the complete computer system. It means it is responsible for managing all the resources (software and hardware) For example: - Operating system, Language processor. It is further divided into three types. They are:-

a)      Language Processor

b)      Operating System

c)       Utility Program

a)      Language Processor:

Language processor is a kind of system software which is responsible for translating as well as converting high level language and low level language into machine cone (o,1) instructions because computer hardware are only able to understand machine code instruction which is known as object code. For example: compiler, interpreter.

It is further divided into three types. They are as follows:-

i)                    Compiler

ii)                   Interpreter

iii)                 Assembler

I)                    Compiler:

Compiler is a translator as well as converter and system software which is responsible for translating high level language into machine code instructions because computer hardware are only able to understand machine code which is known as object code. The compiler executes or translates complete code once a time. For example: Turbo C, JAVA etc

II)                  Interpreter:

Interpreter is a kind of system software which is also known as translator, it is responsible for translating high level language into machine code instructions because computer hardware are only able to understand machine code instructions known as object code Interpreter translating high level language step by step, line by line, it means it reads the instructions line by line, word by word then execute a program.

III)                Assembler:

Assembler is a translator as well as kind of system software. But it is completely different from compiler as well as interpreter. It is responsible for translating low level language (Assembly Language) into machine code instructions because computer hardware are only able to understand machine code instructions which is known as object code.

b)      Operating System:

Operating system is kind of system software which is interface between computer user and computer hardware. It is the most important component of computer system because without operating system we can't boot (Start) computer system. It is also known as master control of the computer system. It is responsible for managing all the computer system. For example: LINUX, MAXC, Windows series (98/XP/Vista/7/8/10 etc.)

c)       Utility Program

Utility programs are also known as service program and housekeeping programs. There are collections of those programs that help the programmer in performing some specific task to reduce the overall programming effort of the programmer. It means by using utility program programmer increase their performance, efficiency and programming skills. For examples: Copy, Paste, Edit, Zoom etc.

2)      Application Software

Application software are those software which are designed and developed by programmer to solve a specific problem by using computer. For the development of application software one is required to use the system software available on computer. Because system software at as interface between computer as well as programmer. For example: Ms.Office, PageMaker, Tally, FreeHand, mercury etc. It is further divided into two types:-

1-      Packaged Software

2-      Tailored Software

Packaged Software:

Packaged software are those software which are journalized set of program designed and development for general purpose. They are used to solve the general problem and they are used to perform multiple types of jobs in multiple fields like banking, financial sector, hospital and research center etc. 

Tailored Software

Tailored software are those software which are specially designed and developed to solve a specific jobs within specific time period for example: To view the result of HSEB Nepal.

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Definition of Computer

Definition of Computer

PC is an advanced programmable electronic machine which recognizes data from the customer and assume that data as showed by predefined heading and give the ached for result. "PC" is gotten from the Latin word "Computer" which means to determine.

Vital Terms used as a piece of Computer

1.   Input: data is the data and heading which is nourishment to the PC.

2.  Input Devices: Input contraptions are those devices which are used to give data and course to the PC. For example: Mouse, console, Scanner et cetera.

3. Output: Output is a result, which is taken from rule memory (RAM).

4. Output Devices: Output contraptions are those devices which are used to show the result. For example: Monitor, Printer, Speaker et cetera.

5. Software: Software is an aggregation of framework furthermore set of information, which are plan and made by programming engineer by using programming vernacular to perform of specific undertaking furthermore wide task. For example: Ms. Office group, PageMaker, Tally, Corel Draw et cetera.

6.   Hardware: Hardware is the physical parts of PC which can be touched and seen. Case in point: Microprocessor, CPU fan, Monitor, RAM et cetera.

7.    Data: Data is a get-together of unrefined materials.

8.   Information: Information is a get-together of data and also took care of data which is significance full.

9.   Program: Program is a course of action of bearing which are use to play out some specific errand.

10.  CPU: It stays for Central Processing Unit. It is a hart and also cerebrum of the PC. It has three crucial parts. They are:

A.  ALU: it stays for Arithmetical and Logical unit which is responsible for playing out all key numerical and intelligible operations like, extension, subtraction, division and duplications.

B.   CU: it stays for Central Unit which is responsible for bringing the rule from rule memory (RAM).

C.   MU: It stays for Memory Unit it is generally called Resister Array which is responsible for securing widely appealing result between time since it is a temporary zone in the CPU.

11.  Microprocessor: It is a processor of CPU which is natural single chip. It is made by Silicon metal. For example: 80286, 80386, Dual Core, i3, i5 et cetera.

12.  Memory: Memory is a chip, contraption, space where we can store data and course.

13.  RAM:- It stands the Random Access Memory it is a key memory which is used to store data brief and it is in like manner used to fabricate the rate of PC and it is also knows as insecure memory since it loses its substance when power supply is off.

14. ROM:- it stays for Read Only Memory it is generally called non-eccentric memory since it doesn't loses its substance when power supply is off. It is for the most part used to store pre portrayed bearings used to execute working system known as firmware.

15.    Firmware:- Firmware are the predefined heading set away on RAM while creation of RAM, use execute working system.

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