Generation Of Computer (Explained-In-Details)

Generation Of Computer (Explained-In-Details)

Generation of Computer

Intensive research and countless experiments on computers led to the sophistication, versatility, and reduced costs of what had once been expensive and huge machines with limited functions. The growth and availability of electronic components have enhanced the possibility of a drastic reduction in size, cost, and failure of components. From the early 40s to date the reliability of computer has increased by 100 folds and the speed of operation has also increased by 10000 folds. Hence, the computers belonging to different times used electronic components with subsequent improvements. Four distinct generations of computers can be recognized.

The First Generation Computers

This generation roughly covers the period 1945-1955. The main components in use were vacuum tubes. The first generation computers had the following characteristics:

1. Large in size.
2. Rigid in operation.
3. Limited memory and computing capacity. Slow- operating speed (millisecond). Contained vacuum tubes.
4. Used machine language to program. Generated more heat.
5. Too many maintenance problems.
6. Very expensive.

The Second Generation Computers

The second generation of computers covers the period of 1956-1965. This generation of computers is distinguished by the use of transistors. A transistor is a tiny semiconductor device. The computers of this generation had the following characteristics:

1. Considerable reduction in physical size. Comparatively more reliable.
2. Comparatively large memory.
3. Greater operating speed (microsecond).
4. Contained transistors as the essential component and consumed less power.
5. Improved computing capacity.
6. Generated less heat as compared to the first generation computers.
7. Faster and better input-output devices.

The Third Generation Computers

As the next step, functions of several transistors were put together on a single chip (wafer) of silicon. These chips are called Integrated Circuit (IC) chips. In the third generation computers, the main component in use was ICs. This generation of computers covers the period of 1965-1975. The computers of this generation had the following characteristics:

1. Greater miniaturization.
2. Flexible in operation.
3. Large memory.
4. High operating speed (nanoseconds). Very reliable.
5. Contained ICs (Integrated Circuits). Random access is possible.
6. Time-sharing and multiprocessing.
7. Higher-level languages like COBOL, FORTRAN, etc. were used. Compatibility with other systems.

The Fourth Generation Computers

The advancement in computer electronics could pack thousands of components into very small assemblies known as LSI (Large Scale Integration) and this led to the production of fourth-generation computers. The microprocessor was developed where an entire CPU was accommodated on a single chip. Intel 4004 was the first microprocessor that was updated to Intel 8080 and this invention led to the beginning of the usage of compact design and is still used in a major way. These systems provide increased input-output capabilities and storage capacity, longer component life, greater reliability, modular design, and increased speed. This generation of computers includes the computers developed from 1975 to the present day. Characteristics of the Fourth Generation Computers are as follows:

1. Used Large Scale Integration (LSI) and Very Large Scale Integration (VLSI).
2. Increased input-output capabilities. High processing speed.
3. User-friendly.
4. Comparatively more diminutive in size and more reliable.

The Fifth Generation Computers (Future Generation)

Many attempts have been made for several years to develop more efficient processors by using genetically engineered proteins. It is expected that the computers having such processors will understand natural languages and have knowledge processing capabilities called Artificial Intelligence.

Till the fourth generation computer, the significant stress was on improving the hardware to achieve processing speed, but scientists began feeling the lack of intelligence in computers, so they are trying to give new artificial intelligence to the fifth generation computers. These computers will then have the thinking power and capability to make decisions like human beings and prove better than a man in certain areas. These machines will be capable of knowledge processing, handling billions of instructions per second, and unimaginable storing capacity. High-level languages will become obsolete for these machines, and new computer languages and related software will be developed. The fifth-generation computers are expected to have the following characteristics.

1. Artificial Intelligence.
2. High-performance multiprocessors.
3. Thinking power and capability to understand natural languages and make decisions like human beings.
4. Very high processing speed and storage capacity
5. Intelligent programming Knowledge-based system.

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Number System In Computer

Number System In Computer

Number System

A computer is a man-made electronic device. It does not have its own intelligence but is capable of carrying out different operations. The operation of the computer is based on certain principles, methods, and logic. This deals with the conceptual aspect of data representation within the computer and conversion among binary, octal, and hexadecimal number systems.

In modern computers, memory and processing units are made up of a set of silicon chips, each of them containing a large number of transistors, A transistor is a two-state device like a switch having an OFF state and an ON state. The OFF state can be represented by 0 and the ON state is represented by 1. These 0 and 1 are called Binary Digits or BITS. Thus, a computer does not understand anything other than 0 and 1 i.e. computer circuits can respond only to the binary state. So data and program must be coded in a binary form before it goes into the computer.

ON    OFF   ON    OFF   ON    OFF   ON   OFF

1        0        1         0        1         0        1       0

The collection of eight such switches each representing a bit is called a Byte.

i. e. 8 bits = 1 byte

A byte is equivalent to one ASCII character i.e. a number, a letter, a mathematical symbol, or a punctuation mark.

Binary Coding

The normal character (alphabet, number, etc.) as we know has to be broken down to a set of simple codes, so a computer can understand it. All the characters have been coded for the sake of easy exchange of information between the different systems and to make communication possible between users and the machine. ASCII (American Standard Code for Information Interchange) coding system specifies all the lower and upper case letters, numbers, punctuation symbols, and special control commands. The system uses 8 bits to code each character, the first 7 bits represent the character and the eighth bit (called parity bit) enables the computer to check the information we have put in. A maximum of 256 characters can be coded under the ASCII coding system.

For example, the ASCII code for A = 65 when A is pressed the binary equivalent of 65 i.e. 1000001 is transmitted as pulses.

 Digit: A single character in a numbering system or counting system having a specific radix or base.

Bit, Nibble, Byte, and Computer Word 

Computers do not understand normal alphabets and numbers in the form we understand. It has to be broken down into computer understandable code with the help of a coding system so that communication between the user and computer is possible. Previously, computers were based on EBCDIC (Extended Binary Coded Decimal Interchange Code) coding system (eight bits coding system), but most of the modern computers are based on ASCII (American Standard Code for Information Interchange) coding system. ASCII coding system uses 7 bits to represent a character or a number and one bit is added before seven bits to form eight bits code. The additional bit is called the parity bit. The parity bit allows the computer to double-check the information we have input in.

Bit: It stands for Binary digiT. A single digit in a binary number a 0 or 1 is called a bit. Within the computer, a bit is physically a memory cell, a magnetic spot on a disk or tape, which can represent a binary state (0 or 1). 

Nibble: It is a combination of four bits i.e. one Nibble consists of four bits. 

Example: 0101 is one Nibble.

Byte:  It is a common unit of computer storage. It is made up of eight bits. 

Byte: Example: 01001101 is one byte. 

Computer Word:

It is the computer's internal storage unit that refers to the number of bits the computer uses for processing at one time. It differs from computer to computer. 

FOR example, A 16-bit computer processes two bytes at the same time i.e it uses two bytes of words. A 32-bit computer processes four bytes at a time, so the word length for that computer is four bytes.

Binary to Hexadecimal Conversion 

The method for conversion of a binary number to hexadecimal number is similar to that of conversion of a binary number to octal number except the grouping is done using four bits as the hexadecimal digit is represented in terms of four bits.

Hexadecimal to Binary Conversion

The method for conversion of hexadecimal number to binary number is similar to that of conversion of octal number to binary number except for the binary representation of each hexadecimal digit is done in terms of four bits.

Octal to Hexadecimal Conversion 

An octal number can be converted into its equivalent hexadecimal number by, first converting to binary and then the decimal equivalent to hexadecimal number.

Hexadecimal to Octal Conversion

A hexadecimal number can be converted into its equivalent octal number by, first converting to binary and then the binary equivalent to octal number, or first converting to decimal and then the decimal equivalent to hexadecimal number.

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Q-BASIC Program (WAP to find a factor, reverse order, series, palindrome, Armstrong, prime, and composite)

Q-BASIC Program (WAP to find a factor, reverse order, series, palindrome, Armstrong, prime, and composite)

Write a program to display the following series:

1.   3  9  27  81............. up to 10th terms

CLS

FOR X=1 TO 10

N=3^X

PRINT N;

NEXT X

END

2. 100  97.5  95  92.51....up to 10th terms

CLS

N=100

FOR I = 1 TO 10

PRINT N;

N = N-2.5

NEXT I

END

3.  7    77    777     7777    77777

CLS

A=7

FOR I=1 TO 5

PRINT A;

A-A*10+7

NEXT I

END

4.   2   1   3    4    7   -------------- UP TO 10TH TERMS. (FIBONACCI SERIES)

CLS

A=2

B=1

PRINT A; B;

FOR 1=1 TO 8

C=A+B

PRINT C;

A=B

B=C

NEXT 1

END

Or

CLS

A=2

B=1

FOR 1-1 TO 5

PRINT A; B;

A=A+B

B=A+B

NEXT I

END

5.    55555    5555   555   55    5

CLS

P=55555

X=1

WHILE X<=5

PRINT P;

P=P\10

X=X+1

WEND

END

6. Write a program to display the factorial of a given number.

CLS

INPUT "Enter a number"; N

P=1

FOR I=1 TO N

P=P*I

NEXT I

PRINT "Factorial is;" ;P

END

7. Write a program to input any input number and print it in reverse order.

CLS

INPUT "Enter any number"; N

WHILE N<>0

R=N MOD 10

S= (S*10)+R

N=N\10

WEND

PRINT "Reverse of the given number is"; S

END

8. Write a program to input any number and display the sum of individual digits of the given number.

CLS

INPUT "Enter any number"; N

WHILE N<> 0

R=N MOD 10

S=S+R

N=N\10

WEND

PRINT "The sum of individual digits is"; S

END

9. Write a program to display the factors of the given number.

CLS

INPUT "Enter a number"; NUM

FOR I= 1 TO NUM

IF NUM MOD I=0 THEN

PRINT I;

END IF

NEXT I

END

10. Write a program to enter a number and check whether the number is palindrome or not.

CLS

INPUT "Enter a number"; N

P=N

DO WHILE N<>0

 R=N MOD 10

S=S*10+R

N=N\10

LOOP

IF P=S THEN 

PRINT "The number is a palindrome"

ELSE

PRINT "The number is not a palindrome"

END IF

END

11. Write a program to input a number and check whether the number is Armstrong or not. The number is called Armstrong if the sum of the cubes of each individual digit is equal to the given number]

CLS

INPUT "Enter a number"; N

P=N

WHILE NO

R=N MOD 10

A=A+R^3

N= N \ 10

WEND

IF A =P THEN

PRINT "The number is Armstrong"

ELSE

PRINT "The number is not Armstrong"

ENDIF 

END

12. Write a program to input any number from the user and then display whether it is prime or composite.

CLS 

INPUT "ENTER ANY NUMBER"; N

FOR I=1 TO N

R=N MOD I

IF R=0 THEN

C=C+1 

ENDIF

NEXT I

IF C=2 THEN

PRINT "THE GIVEN NUMBER IS PRIME"

ELSE

PRINT "THE GIVEN NUMBER IS COMPOSITE"

ENDIF 

END

13. Write a program to display all the prime numbers from 2 to 100.

CLS 

FOR I = 2 TO 100

C=0

FOR J = 1 TO I

R = I MOD J

IF R = 0 THEN

C=C+1

ENDIF

NEXT J

IF C=2 THEN 

PRINT I;

ENDIF

NEXT I 

END

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Q-basic programs (To Find name, odd, even, series, multiplication table, divisible, a sum of even or odd numbers)

Q-basic programs (To Find name, odd, even, series, multiplication table, divisible, a sum of even or odd numbers)

1. How do you write a flowchart and QBasic code to generate series 5, 10, 15, 20, up to 10 terms?

CLS
A=5
FOR I = 1 TO 10
PRINT A;
A=A+5 
NEXT I 
END

2. How do you write a program in QBasic to write a table of 1 to 10 number

CLS

FOR I = 1 TO 10

FOR J = 1 TO 10

PRINT J ;"*"; I ;"="; (J*I)

NEXT J

NEXT I

END

3. How do I write a QBASIC program for multiples of 9?

CLS

A =9

FOR I = 1 TO 10 

PRINT A; "*";I; "="; ( A*I)

NEXT I 

END

4. WAP To print my school name 100 times?

CLS
A$ = "ENTER YOUR SCHOOL NAME"
FOR I =1 TO 100
PRINT A$ 
NEXT I 
END

5. WAP To print my name 20 times?

CLS
A$ = "ENTER YOUR NAME"
FOR I =1 TO 100
PRINT A$ 
NEXT I 
END

6. How do you write a QBasic program to check whether a number is exactly divisible by 3 or 7?

CLS 
INPUT ''ENTER A NUMBER"; N
IF N MOD 3 = 0 AND N MOD 7 = 0 THEN
PRINT "THE NUMBER IS DIVISIBLE BY 3 OR 7"
ELSE 
PRINT ''THE NUMBER IS NOT DIVISIBLE BY 3 OR 7"
ENDIF

END

7. How do I write a QBasic program to print a table of 15?

CLS

A = 15

FOR I = 1 TO 10

PRINT A; "*"; I; "=" (A*I)

NEXT I 

END

8. How would you write QBasic programs to print the first ten even numbers?

CLS 

A = 2

FOR I = 1 TO 10

PRINT A

A = A+2

NEXT I 

END

9. What is the program for even numbers between 1 to 20 in QBasic?

CLS 

A = 2

FOR I TO 20

PRINT A

A = A+2

NEXT I

END

10. What is a program in QBASIC to find the sum of even numbers between 10 and 50?

CLS

FOR I = 10 TO 50     STEP-2

PRINT I

S = S+ 1 

NEXT I 

PRINT "THE SUM IS "; S

END

11. What are the steps to find the sum of 100 natural numbers in Q basic?

CLS

FOR I = 1 TO 100   

PRINT I

S = S+ I

NEXT I

PRINT "THE SUM OF NATURAL NUMBER IS"; S

NEXT I

END

12. What is the sum of the first 100 even numbers?

CLS

FOR I = 2 TO 1OO     STEP-2

PRINT I

S = S + I

NEXT I

PRINT " THE SUM OF FIRST 100 EVEN NUMBER IS"; S

END

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Guided media and Unguided media with example (Explained-In-Details)

 Guided media and Unguided media with example (Explained-In-Details)

Wired or bounded media (Guided Media)

Bounded media is the type of transmission media in which data and signals are transferred in a closed conductor through the use of cables or wires. Two or more devices that are near to each other can be connected directly using cables. This is an easy, fast and secure way to transfer data and information from one computer to another. The three types of cables that are used in a computer network are:

1. Twisted pair Wire
2.  Co-axial Cable
3. Fiber Optic Cable

Twisted pair cable

Twisted pair cables are used only for lower bandwidth. It consists of two isolated strands of copper wire twisted around each other. It is also widely used in landline telephone. The RJ-45 connector is the most popular connector used in twisted pair cables. There are two types of twisted-pair cables. They are UTP (Unshielded Twisted Pair) and STP (Shielded Twisted Pair).

UTP (Unshielded Twisted Pair)

UTP cables do not have metal shields except plastic coating. It contains several twisted pairs of wires with a simple plastic casing. It is commonly used to transfer data and information in telephone and LAN connections. It is cheaper and easier to work with, but does not offer high bandwidth and good protection from interference. Its grade starts from cat1 to cat7. It can support data transmission rates from 10 to 100 Mbps.

STP (Shielded Twisted Pair)

STP cable is shielded with a metal sheath along with a plastic coating. It offers high bandwidth and good protection from interferences. Cabling is more difficult to install and more expensive than UTP. Its bandwidth is 10 to 500 Mbps (Megabits per second). RJ 45 connector is used in STP. It is cheaper than fiber optic cable. It provides better protection against EMI(Electromagnetic Interference) than UTP.

Co-axial cable

Co-axial cable is made up of copper or aluminum wire with an inner conductor surrounded by an insulating layer and again surrounded by conducting shield. So it consists of two conductors inner and outer conductors. It carries higher bandwidth and noise immunity. It does not bend readily. This cable consists of one or more small cables in a protective covering. It offers a very high data transfer rate and can be placed underground and laid on the floors of lakes and oceans. BNC and T connectors are the most popular connector used in co-axial cable. 

Fiber optic cable

Fiber optic cable is a thin filament of plastic or glass fiber wrapped in a protective jacket to transmit data. It consists of strands of glass-like thread, each about the diameter of a human hair. It offers a high-speed data transmission rate because data travel as high-speed pulses of light. So it is a widely used cable especially in ISP (Internet Service Provider). ST (Straight Tip) connector, SMA (Screw Mounted Adaptors), SC (Subscriber Connector), etc. are the common connectors used in fiber optic cable.

Wireless or unbounded media (Unguided Media)

Unbounded media is the type of transmission media in which data and signals are transferred through the help of air. It is used to transfer data within large geographical areas or globally without the use of interconnecting wires or cables. It uses other components such as radio signals, microwaves, or infrared to connect networks for receiving and transmitting electronic data. The types of wireless communication are:

1. Radio wave
2. Microwave System
3. Infrared
4. Satellite Communication

1. Radio Wave

The radio wave is an electronic magnetic wave. It is used in rural and hilly areas. The data and information can be changed into audio signals using high-frequency waves based on frequency, amplitude, and phase modulation. It is a wave or RADIO WAVES pattern received after the modulation of signals. The types of modulation signal are FM (Frequency Modulation): The waves are modulated due to their frequency change. AM (Amplitude Modulation): The waves are modulated due to their amplitude change. PM (Phase Modulation): The waves are modulated due to their phase change.

2. Microwave Systems

Microwave signals are similar to radio and television signals and are used to transmit data signals through the atmosphere. It provides high-speed data transmission. It is also known as the line of sight communication as signals cannot be bent and cannot pass through obstacles like hills and tall buildings. So, very high towers are used to mount the signals that should be in a clear line of sight. Chain of towers I required to transmit the microwave signals in a long distance. Repeaters are used to amplify the signal. The other important devices are the digital modem and antenna.

3. Infrared

Infrared light is an electromagnetic form of radiation. It comes from heat and thermal radiation, and it is not visible to the naked eyes. In infrared transmission, senders can be simple Light Emitting Diode (LED) or laser diodes. Photodiode act as receivers. Infrared is used in wireless technology devices or systems that convey data through infrared radiation. It is used for short-range communications and control. Infrared technology is used in instruction detectors; robot control systems, medium-range line of sight laser communication, cordless microphone, headsets, modems, etc.

4. Satellite communication

Both microwaves signals and telephone signals can be relayed to an earth station for transmission to a communication satellite. Satellite communication is used to transfer data wirelessly worldwide. The earth station consists of a satellite disk that functions as an antenna communication equipment to transmit and receive data from satellites passing overhead. It is not disturbed by hills and tall buildings and is visible from any point. So sender and receiver can easily communicate with each other using antenna by aiming the satellite. It is very expensive for placing satellites along the earth's orbit. It is an artificial satellite placed in outer space and most of the countries are using their own satellite to communicate.

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Computer Network Components

Computer Network Components

Different network component

The basic elements of a computer network include hardware, software, and protocols. The hardware used in the network is a modem, routers, switches, bridges, hubs, etc.

MODEM

MODEM stands for Modulation and Demodulation. The modem is a device that directly converts the digital signal from a computer into analog form for transmission over an analog link such as a telephone line which is called the modulation phase. It receives analog signals from the phone line and converts them into digital signals for the computer which is called the demodulation phase. So, it is a device that connects computers to ISP (Internet Service Provider) with the help of a telephone line or router device. The modem which is placed inside the CPU Casing is called an internal modem. The modem which is placed outside the Casing is called an external modem. Wireless modems convert digital data into radio signals and vice versa. Modems came into existence in 1960. The main features of modem are:

1. Automatic cable sensor and calling card dialing
2.  Call progress detection and caller ID
3. Analog Cellular and GSM communications
4. Dialing stored phone numbers and digital line guard
5. Exclusive line probing and redialing the last dialed number

NIC

It is a Network Interface Card, which connects each computer to the wiring to the network. NIC is placed in motherboard expansion slots. It provides a port on the back of the computer to connect to the network. It controls the flow of data to and from computers in a network environment. It is used in LAN. Token ring and Ethernet are examples of NIC cards.

Hub

Hub is a connectivity device. It contains multiple ports for connecting to network components. It connects the computers in a star topology. It is simple, easier to install, low in cost, as compared to other devices. It can receive or send information data, so data packets are sent to all connected devices.

Switch

The switch is a connective device that is capable of forwarding packets directly to the ports associated with particular network addresses. It coordinates file servers and computers. The selected computer can get information through the switch. The switch is new technology and intelligent as compared to the hub. It works faster than a hub.

Connector

Connectors attach components together that are used to connect communication media with network devices. Several types of connectors are available, serving various purposes. It connects NIC cards such as an Ethernet card. It connects cable segments. RJ-45 connector for UTP cable, ST connector for fiber optics cable, BNC connector for co-axial cable, etc. is the different types of connectors. Bridge and gateway are the two connectors that link between two network systems.

Bridge

Bridge connects networks using the same communication protocols or similar networks so that information can be passed from one to the other. The signals are inspected by the bridge and decide whether to forward.

Gateway

The gateway connects networks using different communication protocols or dissimilar networks. It is also called a protocol converter and sends data in any network layer. It is more complex than a switch or router.

Repeater

The repeater is a network device that accepts weak signals and regenerates the signal over the same network to extend the length to which the signal can transmit. It makes it possible for long-distance data transfer. It does not amplify the signal. When the signal becomes weak, they copy the signal bit by bit and regenerate it at the original strength. It is a two-port device.

Router

A router is a device that is used to connect different LANs and WANs in the network. It receives transmitted messages and forwards them to their correct destinations over the most efficient available route. It is a device that routes data packets based on their IP addresses. It has a dynamically updating routing table based on which they make decisions on routing the data packets.

NOS

NOS stands for Network Operating System. It is the Operating System that can support controls and manage the computer network environment. Examples of Network Operating systems are Windows XP, Windows NT, server, UNIX, LINUX, Novel Netware, etc. The most popular Network Operating System is Novell Netware. The major functions of a Network Operating System are  

1. It is used to set up and install a computer network.
2. It enables users to have access, manages, and control all the resources. 
3. It allows adding or removing users from the network.

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