Define Computer? Explain what are different types of Computer.

Semester :-1

Unit:-1

Define Computer? Explain what are different types of Computer.
Ans:-
          Computer is an electronic device, which stores data, process it and gives the results consistently, accurately at very high speed according to our instructions. The word computer is derived from the word "Compute". It means perform or calculate. That's way, the computer is also called as calculating device. The computers can broadly classified into three types namely
 a) Analog Computers
b) Digital Computers
c) Hybrid Computers
a) Analog Computers:-
                                            The analog computer operate by measuring instead of counting. The analog computer works on the supply on continuous electrical signals. The display is also continuous and its output is in the form of graphs.
                In Analog Computer, the input data is a continuously changing electrical or non-electrical information. Computations are carried out with physical quantities such as Voltage, length, Current, Temperature etc. The device measuring such quantities are called analog devices. The advantages of analog computer is that all calculation take place in parallel and hence it is very fast. It is used for engineering and scientific application. But their accuracy is poor as compared to digital computer.
Characteristics :-  

1. It operates by measuring.
2. It requires by measuring.
3. It function on continuously quantity.
4. The output is usually represented in the form of graph.
5. The accuracy of the output is poor.
6. It has limited memory space.
7. It is not versatile i. e. It has limited applications.
8. Speed is very low.
9. These computers are not suitable for business and industry.
10. The calculations are first converted into equations and later converted into electrical signals.

b) Digital Computers :-

                                             As the name implies, the digital computer with quantities represented as digits. In digital computer, both numeric and non-numeric information are represented as string of digits.

             In Digital Computer, the input data is discrete in nature. It is represented by binary notation in the form of "0"s and" 1"s digital computers are much faster than analog computers and are more accurate. Digital computers are largely used for business and scientific applications.

              The basic operation performed by a digital computer is addition. Hence, the other operation such as multiplication, division, subtraction and exponentiation are first changed into "Addition and then compute".

Characteristics :-

1. It operates by Counting
2. It functions on discrete numbers
3. The calculations are converted into binary numbers
4. The output is represented in the form of discrete values
5. Its accuracy is good
6. It has large memory space
7. It is versatile in nature
8. It is suitable for a number of applications
9. It processing speed is high
10. It is highly suitable for business applications

c) Hybrid Computers :-

                                             The Hybrid Computers combines the features of both the analog and digital computers. These are used for special Analytical applications. weather-monitoring system and device used in Intensive Care units (ICU) of the hospitals are example of hybrid Computers.

                 Further more, computers are classified depending on the application as: special purpose Computers and General purpose Computers.

       As the name implies the special purpose computers are designed to perform a specific task or a special application. 

Explain various Computer Generations in detail.

Semester :-1

Unit:-1

Explain various Computer Generations in detail.

The Computer Generation means step-by-step growth in the technology. Originally, the term generation was used to distinguish between varying hardware technologies. But nowadays, it has been extended to include both the hardware and the software, which together make up an entire computer system.
                                  There are totally five generations of computer till today. Each generation will be discussed in detail. The following table illustrates the generations of computer hardware :
S. No. 
Generations of computers 
Components used 
Operating speed 

1.
First Generation 
Vacuum tubes
Milli Seconds 

2.
Second Generation 
Transisters
Micro Seconds 

3.
Third Generation 
Integrated Circuits (IC) (or) SSI (or) MSI
Nano Seconds 

4.
Fourth Generation 
Micro processors (or) LSI (or) VLSI
1 to 10 
Nano Seconds 

5.
Fifth Generation 
Ultra LSI
1 to  100 
Nano Seconds 


a) 1st Generation Computers (1942-1955) :-
                                                                           The magnetic relays of the very first computer were replaced by vacuum tubes. The computers which were made of these vacuum tubes came to be known as the first generation computers. The ENIAC computer made use of 18,000 vacuum tubes and relays. It was capable of performing 5,000 additions in one second. It was bulky in size and needed heavy air conditioning.
Advantages :

1. Vacuum tubes were the only electronic components available at that time.
2. This technology made possible the advent of electronic digital computers.
3. These computers were the fastest calculating device of their time.
4. These computers could perform computations in milli seconds.

Disadvantages :

1. Very big in size
2. Occupies large space
3. High heat production
4. High power consumption
5. High cost
6. NO reliability
7. Vulnerable to frequent hardware failure.
8. Limited Commercial use.
9. Need Constant maintenance.

b) 2nd Generation Computers (1955-1964) :
                                                                            The transistor was invented in 1948 at the Bell laboratories and was capable of performing all the functions of a vacuum tube at a much faster rate. It consumed little power and generated less heat. The computers which were working with transistor came to be known as the second generation computers. These computers were much smaller, consumed less power and generated little heat and were more reliable. These had capability of performing 20,000 to 50,000 additions per second.
Advantages :

1. Small in size
2. Better reliability
3. Computational time is micro seconds
4. Less heat generated
5. Better speed
6. Better portability
7. Less prone to hardware failure.

Disadvantages :

1. Frequent maintenance required
2. Need Air-conditioning
3. Manual Assembly of individual components into a functioning unit was required.
4. High cost
5. Commercial production was difficult.

c) 3rd Generation computers (1964-1975):
                                                                          The new techniques of small scale Integration (SSI) and medium scale Integration (MSI) led to the evolution of Integrated Circuit (IC). As many as few hundred transistor can be housed on a single Integrated Circuit. This chip can be as small as 4 to 8 square centimeters in the area and weight few grams. It consumes very little power and its cost is very low. The computers using the integrated circuit came to be known as third  generation computers. The first computer came from IBM and is called as IBM 360. These computers were small in size and Greater in capacity and performed as many as ten million additions per second.
Advantages :

1. Small in size
2. More reliability
3. Less heat generated
4. Computational time is Nano seconds.
5. Less hardware failure.
6. Low maintenance cost
7. Easily portable
8. General purpose computers.
9. Less power required
10. Commercial production was easier and cheaper.

Disadvantages :

1. Need Air-conditioning
2. Highly sophisticated technology required for the manufacture of IC chips.

d) 4th Generation Computers (1975-1989):
                                                                           The beginning of 1970s saw a totally new face in the computer industry with the introduction of microprocessor. These microprocessor comprised of many LSI (Large scale Integration) and VLSI (Very large scale Integration) circuits having all elements to process the data. These microprocessors have thousands of transistors in them. The computers making use of these microprocessors are known as fourth generation computers.
Advantages :

1. These computers were much more small in size.
2. Very cheap as compared with previous generation computers.
3. Consumed less power
4. Mainframe and super computers fall in this generation.
5. Having more reliability
6. Having less hardware failures.
7. They had large and faster primary and secondary storage.
8. These are the general purpose computers.
9. Object oriented languages are supported.

Disadvantages :
     1. Highly sophisticated technology required for the manufacture of LSI chips.
5th Generation Computers (1989-present) :
                                                                           The fifth generation computers have a new technology called Artificial Intelligence incorporated in them. The computers which were made of these Ultra large scale Integration (USING) came to be known as the fifth generation computers. These computers require new architecture, new memory organizations and new programming languages. These will be the computers that can learn and make decisions.
Advantages :

1. The super computers fall under this generation.
2. Portable PC's also fall under this generation.
3. These computers consumes less power than the predecessors.
4. More user friendly
5. Supports wide operating system environments.
6. Supports newer and powerful applications
7. Having much faster and large primary storage capacity
8. The price range are affordable and very close to human being.
9. Supports parallel programming.

What are the characteristics of a computer? Explain.

Semester :-1

Unit:-1

What are the characteristics of a computer? Explain.

The main and most important characteristics of computer are.

1. Speed
2. Accuracy
3. Diligence
4. Versatility
5. Power of Remembering
6. No. I. Q.
7. No feelings

a) speed :-

                   A computer is a very fast calculating device. It can perform in a few seconds the amount of work that a human being can do in an entire year.

While talking about the speed of a computer, we do not talk in terms of seconds or even milliseconds. A powerful computer is capable of performing about 3 to 4 million instructions per second.

b) Accuracy :-

                         The accuracy of a computer is consistently high and the degree of accuracy of a particular computer depends upon its design. Each and every calculation is performed with the same accuracy.

                 Errors can occur in a computer, but these are mainly due to human than technological weakness, that is, due to imprecise thinking by the programmer or due to inaccurate data.

c) Diligence :-

                       Unlike human beings, a computer is free from tiredness, lack of concentration etc., and hence can work for hours together without creating any error and without grumbling.

d) Versatility :-

                         Versatility is one of the most wonderful things about the computer. One moment, it is preparing the result of particular examination, the next moment it is busy preparing electricity bills, and in between, it may be helping an office secretary to trance an important letter in seconds. In other words, a computer is capable of performing almost any task provided that the task Can be reduced to a series of logical steps. 

e) power of Remembering :-

                                                  A computer can store and recall any amount of information because of its secondary storage capability. Every piece of information can be retained as long as desired by the user and can be recalled as and when required. A computer forgets or looses certain information only when it is asked to do so. So it is entirely upto the user to make a computer retain or forget a particular information. 

f) No. I. Q ( Intelligent Quotient) :-

                                                           A computer is not a magical device. It can only perform tasks that a human being can The difference is that it performs these tasks with unthinkable speed and accuracy It possesses no intelligence of its own. Its I. Q. Is zero, at least till today. It has to be told what to do and in what sequence. Hence, only the user can determine what tasks a computer will perform. A computer cannot take its own decisions in this regard. 

g) No feelings :-

                            Computer have no feelings because they are machines. Although men have succeeded in building a memory for the computer, but no computer possesses the equipment of a human heart. Based on our feelings, taste, knowledge, and experience, we often make certain judgments in our day to day life. But computers cannot make such judgment on their own. Their judgment is based  on the instruction given to them in the form of programs that are written by us.

Define computer? Explain in detail logical organization of digital computer with neat diagram.

Semester :-1

Unit:-1

Define computer? Explain in detail logical organization of digital computer with neat diagram.? 

INTRODUCTION :
                   Computer is a electronic device which stores data, process it, and gives the result consistently, accurately at very high speed according to our instruction. The word computer is derived from the word "compute". It means perform or calculate. So a powerful computer can handle 3 to 4 million instruction per second (MIPS)
Input unit :-
           It is used to send data or programs into computer. There are several kinds of input units are available, they are keywor, light pen, joystick, and mouse, etc.
CPU :-
     Cpu stands for central processing unit. This is the main and most important part of the computer it is made up of three units. They are

• Memory unit
• CU (control unit)
• ALU (Arithmetic and logical unit)

a) memory unit :-
               The function of the memory unit is to store data or programs or information in the format of "ON" and "OFF" states. Because computer is an electronic device which identifies either "ON" and "OFF" states. That's why, all the information or data or programs will be stored inside the computer in the form of "ON" And "OFF" states.
b) CU :-
       CU stand for control unit. This unit to control the overall units either internally (i.e. Memory and ALU) and externally (i.e. Input - output units) connected to computer.
c) ALU :-
               ALU stand for Arithmetic logical unit. It will perform the arithmetic and logical operations.

Block Diagram of Digital computer

Output unit :-
           This unit is used to take the final results. There are two kinds of output units. They are a) Soft copy Device, Ex: monitor and b) Hardcopy Device, Ex: printer, plotter.
      Softcopy device are used to prepare the softcopies (monitor output). Prepare softcopy is used for temporary reference and it will save the stationery and printing cost whereas the hard copy device are used to prepare the hardcopier (paper output). Prepared hardcopy is used for further reference and it will waste the stationary and printing costs for unnecessary output is taken.
Secondary Storage Devices :-
                         This unit is used to store large amounts of data permanently. There are several kinds of secondary storage devices. They are magnetic tapes, magnetic disks, CDs etc.
Peripheral Devices :-
                  Whose devices are connected CPU externally then those devices are called peripheral devices.
Input and output units are called as peripheral devices. 

Define computer. What are advantages and limitations of computer

Semester:-1

Unit:-1

Define computer. What are advantages and limitations of computer?

INTRODUCTION :
                          Computer is a electronic device which stores data, process it, and gives the result consistently, accurately at very high speed according to our instruction. The word computer is derived from the word "compute". It means perform or calculate. So a powerful computer can handle 3 to 4 million instruction per second (MIPS)
Advantages of computer :

• They can help you automate various tasks that you cannot do manually.
• They can help you organize your data and information.
• They have much more computing and calculating power then an ordinary human.
• They can help you communicate with friends, coworkers and contacts.
• It saves you time.
• They may your work to be a lot easier
• They have many search engines to help you find information quickly.

Limitations of computer :

• They can have negative effects on your social life and interactions with other people if you do not maintain the balance between time online and offline.
• They may distract students from their studies.
• Too much time in front of monitor may adversely affect your eyesight.
• Sitting in front of a computer for too long without exercise can cause a weight gain and other health issues. 

What is computer

1st semester

Unit:-1

1.What is computer ?
INTRODUCTION :
                          Computer is a electronic device which stores data, process it, and gives the result consistently, accurately at very high speed according to our instruction. The word computer is derived from the word "compute". It means perform or calculate. So a powerful computer can handle 3 to 4 million instruction per second (MIPS)
PARTS OF COMPUTER :

• Monitor
• Keyboard
• Mouse
• Cpu

Monitor : output unit (soft copy and display result)

Keyboard : input unit (gives instructions)

Mouse : input unit (control Cussor)

Cpu : central process unit