1. The Central Processing Unit(CPU) has a Memory Data Register (MDR) and a Memory Address Register (MAR).
2. The Memory Data Register (MDR) keeps the data which is transferred between the Memory and the CPU. The Program Counter (PC) is a special register in the CPU which always keeps the address of the next instruction to be executed.
3. The Arithmetic and Logic unit of CPU places the address of the memory to be fetched, into the Memory Address Register.
4. A bus is a collection of wires used for communication between the internal components of a computer.
5. The address bus is used to point a memory location. A decoder, a digital circuit is used to point to the specific memory location where the word can be located.
6. The address register is connected with the address bus, which provides the address of the instruction. A data bus is used to transfer data between the memory and the CPU.
7. The data bus is bidirectional and the address bus is unidirectional. The control bus controls both read and write operations.
8. The read operation fetches data from memory and transfers to MDR. A single control line performs two operations like Read/Write using 1 or 0.
9. Also, the write operation transfers data from the MDR to memory. This organisation is shown below.

10. The word in the RAM has the same size (no.of bits) as the Memory Data Register (MDR). If the processor is an 8-bit RAM processor like Intel 8085, its MDR and the word in the both have 8 bits.
11. If the size of the MDR is eight bits, which can be connected with a word in the memory which is also eight bits size. The data bus has eight parallel wires to transfer data either from MDR to word or word to MDR based on the control(Read or write).

13. This control line is labeled as which becomes 1 means READ operation and 0 means WRITE operation. 

14. These pictures show the contents of MDR and the word before and after the READ operation.
i. The read operation transfers the data(bits) from word to Memory Data Register.
ii. The write operation transfers the data(bits) from Memory Data Register to word.

The main purpose of using an operating system:
(i) It controls and coordinates all the activities of a computer system.
(ii) It provides an environment for a computer user to execute programs on computer hardware in a convenient and efficient manner.
(iii) It enables the user to design the application, and also it provides an interface to interact with the computer and controls the execution of all kinds .of programs without knowing the internals of the hardware.
(iv) It interprets the command and instructions to perform the specified tasks.
(v) It coordinates and assigns the compilers, assemblers, utility programs to the users.
(vi) It detects errors present in the hardware and software.
(vii) It maintains the internal time clock.
(viii) It protects itself from being destroyed by any users.
(ix) It serves two major functions
1. Supervision (Prevent errors)
2. Management (Operation and control of I/O devices)
(x) It loads the program itself into memory so that user can interact with hardware and software.

98.46₁₀

2. Fractional part
0.46 x 2 = 0.92 = 0
0.92 x 2 = 1.84 = 1
0.84 x 2 = 1.68 = 1
0.68 x 2 = 1.36 = 1
0.36 x 2 = 0.72 = 0
0.72 x 2 = 1.44 = 1
98.46₁₀ = (1100010.011101...)₂

Read-only memory (ROM):
1. Read only memory refers to special memory in a computer with pre-recorded data at manufacturing time which cannot be modified.
2. The stored programs that start the computer and perform diagnostics are available in ROMs. ROM stores critical programs such as the program that boots the computer.
3. Once the data has been written onto a ROM chip, it cannot be modified or removed and can only be read.
4. ROM retains its contents even when the computer is. turned off. So, ROM is called as a non-volatile memory.
Programmable Read-Only Memory (PROM):
1. Programmable read-only memory is also a nonvolatile memory on which data can be written only once. Once a program has been written onto a PROM, it remains there forever.
2. Unlike the main memory, PROMs retain their contents even when the computer is turned off.
3. The PROM differs from ROM. PROM is manufactured as a blank memory, whereas a ROM is programmed during the manufacturing process itself.
4. PROM programmer or a PROM burner is used to write data to a PROM chip. The process of programming a PROM is called burning the PROM.
Erasable Programmable Read-Only Memory (EPROM):
1. Erasable Programmable Read Only Memory is a special type of memory which serves as a PROM, but the content can be erased using ultraviolet rays.
2. EPROM retains its contents until it is exposed to ultraviolet light. The ultraviolet light clears its contents, making it possible to reprogram the memory.
3. An EPROM differs from a PROM, PROM can be written only once and cannot be erased.
4. EPROMs are used widely in personal computers because they enable the manufacturer to change the contents of the PROM to replace with updated versions or erase the contents before the computer is delivered.
Electrically Erasable Programmable Read Only Memory (EEPROM)
1. Electrically Erasable Programmable Read Only Memory is a special type of PROM that can be erased by exposing it to an electrical charge.
2. Like other types of PROM, EEPROM retains its contents even when the power is turned off.
3. Comparing with all other types of ROM, EEPROM is slower in performance.

(i) Basic components of computer :
The Basic components are I/O Unit, CPU, ALU, Control Unit, Storage Unit.
Input unit:
Input unit is used to feed any form of data to the computer. It can be stored in the memory unit for further processing.
Ex. Keyboard, Mouse, Scanner, Retinal scanner, Track ball.
Central processing unit:
CPU is the major component and it controls the operation of all other components such as memory, input and output units. The CPU has three components namely control unit, Arithmetic and logic unit (ALU) and memory unit.
Arithmetic and logic unit:
The ALU is a part of the CPU where arithmetic operations like addition, subtraction, multiplication, divisions and logical operations will takes place.
Control unit:
The control unit controls the flow of data between the CPU, memory and I/O devices. It also controls the entire operation of a computer.
Output unit:
An output device is a hardware component that conveys information to the user in an understandable form.
Ex. Monitor, printer, plotter
Memory unit:
The memory stores everything that computer works with. The memory unit is of two types namely primary memory and secondary memory. The primary memory stores the data and instructions temporarily. Whereas the secondary memory stores the data permanently. The primary memory is volatile and secondary memory is non-volatile.

(a) Inkjet Printer:
(i) Inkjet printer use colour cartridges which combined magenta, yellow and cyan inks to create colour tones.
(ii) A black cartridge is used for monochrome output. Inkjet printer works by spraying ionised ink at a sheet of paper.
(iii) The speed of inkjet printers generally range from 1-20 ppm (page per minute)
(iv) An inkjet printer can spread millions of dots of ink at the paper every single second.
(v) They use the technology of firing ink by heating it so that it explodes towards the paper in bubbles or by using piezo electricity in which tiny electric currents are controlled by electronic circuits.
(b) Multimedia Projector:
(i) Multimedia projectors are used to produce computer output on a big screen.
(ii) These are used to display presentations in meeting halls or in class rooms.
(c) Barcode/ QR code Reader:
(i) A Bar code is a pattern printed in lines of different thickness.
(ii) The Bar code reader scans the information on the bar codes transmits to the computer for further processing.
(iii) The system gives fast and error free entry of information into the computer.
Quick response (QR) code:
The QR code is the two dimension bar code which can be read by a camera and processed to interpret the image.

x\(= {-b \pm \sqrt{b^2-4ac} \over 2a}\)
1. Quadratic solve (a, b, c)
2. -- inputs: b²-4ac > = 0 where a, b, c are real numbers, a ≠ 0
3. -- outputs: x₁ and x₂ are real numbers such that a(x₁)² + bx₁ + c = 0 and a(x_₂)² + bx_₂ + c = 0

1101010₂ + 101101₂
1101010
+101101
________
10010111
________
1101010₂ + 101101₂  = 10010111₂

A gate is a basic electronic circuit which operates on one or more signals to produce an output signal.
The three fundamental gates are AND, OR and NOT gates.
AND Gate
The AND gate can have two or more input signals and produce an output signal. The output is "true" only when both inputs are "true", otherwise, the output is "false". In other words the output will be 1 if and only if both inputs are 1; otherwise the output is 0. The output of the AND gate is represented by a variable say C, where A and B are two and if input boolean variables. In boolean algebra, a variable can take either of the values '0' or '1'. The logical symbol of the AND gate is

The Truth Table For AND Gate is

Input		Output
A	B	C
0	0	0
0	1	0
1	0	0
1	1	1

OR Gate;
The OR gate gets its name from its behaviour like the logical inclusive "OR". The output is "true" if either or both of the inputs are "true". If both inputs are "false" then the output is "false". In other words the output will be 1 if and only if one or both inputs are 1; otherwise, the output is 0. The logical symbol of the OR gate is

The truth table For OR Gate is

Input		Output
A	B	C
0	0	0
0	1	1
1	0	0
1	1	1

NOT Gate;
The NOT gate, called a logical inverter, has only one input. It reverses the logical state. In other words the output C is always the complement of the input. The logical symbol of the NOT gate is

The truth table for NOT gate is

Input	Output
A	C
1	0
0	1

S.No	Navigational method	Located on	Ideally suited for
1.	Start button	Task bar	Quick access common apps and settings
2.	My computer	Desktop	Exploring your disk drives and using system tools.
3.	Windows Explorer	Task bar	Seeing hierarchy of all computer contents and resources in one window.
4.	Quick Launch	Task bar	To open the programs quickly.

The logic gates like NAND, NOR, XOR and XNOR are derived gates which are derived from the fundamental gates AND, OR NOT.
(1) NAND gate:
The NAND is the combination of NOT and AND. The NAND is generated by inverting the output of an AND operation.
Output: y = \(\overline { \left( A.B \right) } \)

The truth table for NAND gate is

Input		Output
A	B	y = \(\overline { \left( A.B \right) } \)
0	0	1
0	1	0
1	0	0
1	1	0

(ii) NOR gate:
The NOR is the combination of NOT and OR. The NOR is generated by inverting the output of an OR operation.
Logic function: y = \(\overline { \left( A+B \right) } \)

the truth table for NAND gate is

Input		Output
A	B	y = \(\overline { \left( A+B \right) } \)
0	0	1
0	1	0
1	0	0
1	1	0

(iii) XOR gate:
The XOR (exclusive - OR) gate acts in the same way as the logical either /or.

the truth table 

Input		Output
A	B	C
0	0	0
0	1	1
1	0	1
1	1	0

(iv) XNOR gate:
XNOR (exclusive - NOR) gate is a combination of XOR gate followed by an inverter.
Logic function: y= \(\overline { A \ B } \)

the truth table 

Input		Output
A	B	C
0	0	1
0	1	0
1	0	0
1	1	1

Boolean function:
\(\mathrm{C} =\overline{\mathrm{A} \oplus \mathrm{B}} \)
\(=\overline{{\overline{\mathrm{A}}} \cdot \mathrm{B}+\mathrm{A} \cdot \overline{\mathrm{B}}} \)
\(=\overline{\overline{\mathrm{A}} \cdot \mathrm{B}} \cdot \overline{\mathrm{A} \cdot \overline{\mathrm{B}}} \)
\(=(\overline{\mathrm{A}}+\overline{\mathrm{B}})(\overline{\mathrm{A}}+\overline{\bar{B}}) \)
\(=(\mathrm{A}+\overline{\mathrm{B}})(\overline{\mathrm{A}}+\mathrm{B}) \)
\(=\mathrm{A} \overline{\mathrm{A}}+\overline{\mathrm{AB}}+\mathrm{AB}+\mathrm{B} \overline{\mathrm{B}}  \quad \mathrm{A \overline {A }}=\mathrm{O}\)
\(\mathrm{C} =\overline{\mathrm{A}} \overline{\mathrm{B}}+\mathrm{AB}\)

power (5,2) = 5 × 5  = 25
power (x, n) raise x to the power n
Algorithm :
power (x, n) 
If n = 0 -- base case
1
else -- rrecursion step
if n is odd
x * power (x, n - 1)
else 
p = power (x, n/2)
p * p
To find a ¹⁰ :

Let the variables a, b, c represent Glass A, Glass B and Glass C and a, b, c can store values APPLE, GRAPE or EMPTY.
Specification:
1 exchange (a, b)
2-inputs: a, b: APPLE, GRAPE
3-outputs: a, b: = GRAPE, APPLE
Algorithm:
1. exchange (a, b)
2. a, b, c :- APPLE, GRAPE, EMPTY.
3. c:=b
4. -- a, b, c :- APPLE, EMPTY, GRAPE,
5. b:= a
6. --a, b, c = EMPTY, APPLE, GRAPE
7. a: = c
8. --a, b, c = GRAPE, APPLE, EMPTY

Type of Error	Description
Syntax Error	Syntax errors occur when grammatical rules of C++ are violated.
Semantic Error	Semantic Error occur when there is wrong use of variable/ operator/order of execution etc. It is also called as Logical Error.
Run-time error	A run time error occurs during the execution of a program. It is occurs because of some illegal operation that takes place.

#include <iostream>
using namespace std;
int main()
{
int a1, b1 lem, ged-1, p;
cout << "\n Enter 1st no:";
cin>>a1;
cout << "\n Enter 2nd no:";
cin >> b1;
p=a1*b1;
for (int i = al; i<-p; i++)
if (i%al == 0) && (i%b1 == 0)
{
1cm=i;
break;
}
cin.get():
cout << "L.C.M. =" <<lcm<<endl;
gcd=p/LCM;
cout<<"G.C.D="<< ged;
cin.get():
return 0;
}

#include <iostream>
using namespace std;
#include <math.h>
int main()
{
int x, n;
float sum= 0;
cout<<"Enter the value for x:";
cin>>x;
cout<<"Enter the number of terms";
cin>>n;
for (int i=0; i<n; i++)
sum = sum + Pow(x,i);
cout<<"Sum="<< Sum<<endl;
cin.get();
return 0;
}

A function that calls itself is known as recursive function. And, this technique is known as recursion.
#include
using namespace std;
int factorial(int);//Function prototype//
int main ()
{
int no;
cout <<"\nEnter a number to find its factorial;";
cin>>no;
cout <<"\nFactorial of Number" < return 0;
}
int factorial(int m)
{
if (m>1)
{
return m*factorial(m-1);
}
else
{
return 1;
}
}
Output:
Enter a number to find its factorial: 5
Factorial of Number 5 = 120

Scope refers to the accessibility of a variable.
There are four types of scopes in C++
(i) Local Scope
(ii) Function Scope
(iii) File Scope
(iv) Class Scope
(i) Local Scope
1. A local variable is defined within a block. A block of code begins and ends with curly braces {}.
2. The scope of a local variable is the block in which it is defined.
3. A local variable cannot be accessed from outside the block of its declaration.
4. A local variable is created upon entry into its block and destroyed upon exit;
Example:
int main()
{
int a,b;    //Local variable
}
(ii) Function Scope
1. The scope of variable within a function is extended to the function block and all sub-blocks therein.
2. The lifetime of a function scope variable is the lifetime of the function block.
Example:
int sum(intx, int y);  //x and y has function scope.
(iii) File Scope
1. A variable declared above all blocks and functions (including main()) has the scope of a file.
2. The lifetime of a file scope variable is the lifetime of a program.
3. The file scope variable is also called as global variable.
Example:
#include<iostream>
using namespace std;
int x,y;   // x and y are global variable
void main()
{
,,,,,
}
(iv) Class Scope
1. Data members declared in a class has the class scope.
2. Data members declared in a class can be accessed by all member functions of the class.
Example:
Class example
{
int x,y;   //x and y can be accessed by print() and void():
void print():
void total();
};

An array of structures is declared in the same way as declaring and array with built-in data types like int or char. A class may contain many students. So, the definition of structure for one student can also be extended to all the students. If the class has 20 students, then 20 individual structures are required. For this purpose, an array of structures can be used
The following program read the details of 20 students and prints the same.
#include< iostream >
using namespace std;
struct Student
{
int age;
float height, weight;
char name[30];
};
void main()
{
Student std[20];
int i;
cout << "Enter the details for 20 students" << endl;
for(i=0;i<20;i++ )
cout << " Enter the details of student'' << i+ 1<< endl;
cout << " Enter the age:"<< endl;
cin >> std[i].age;
cout << "Enter the height:" << endl;
cin >> std[i].height;
cout << "Enter the weight" << endl;
cin >> std[i].weight;
}
cout << "The values entered for Age, height and weight are''< for(i=0;i<20;i++ )
cout << "Student'' << i+ 1<< "\t" << std[i].age << "\
cout << "std[i].height << "\t" << std[i].weight;
}

Call by reference :
In this method of passing the structures to functions, the address of a structure variable /object is passed to the function using address of (&) operator. So any change made to the contents of structure variable inside the function are reflected back to the calling function.
#include< iostream >
using namespace std;
struct Employee {
char name[50];
int age;
float salary;
};
void readData(Employee&);
void printData(Employee);
int main()
{
Employee p;
readData(p );
printData(p );
return 0;
}
cout << "Enter Full Name:";
cin.get(p.name,50);
cout << "Enter age:";
cir >> p.age;
cout << "Enter salary:";
cin >> p.salary:
}
void printData(Employee p)
{
cout << "\nDisplaying Information." << endl;
cout << "Name: " << p.narne << endl;
cout << "Age:" << p.age << endl;
cout << " Salary: " << p.salary;
}
Output.
Enter Full name: Kumar
Enter age: 55
Enter salary: 34233.4
Displaying Information.
Name: Kumar
Age: 55
Salary: 34233.4

#incluede< iostream >
using namespace std;
#include< string.h >
struct college
{
int prof.id;
char pname[20];
char dept[20];
} p[10];
int main()
{
int i;
for (i=0; i<10; i++)
{
cout << "Enter professor.id'' << endl;
cin >> p[i].prof_d;
cout << "Enter proferssor name'' << endl:
cin >> p[i].pname;
cout << "Enter department'' << endl;
cin >> p[i].dept;
}
for(i=0;i < 10; i++) 
{
int flag= 1;
if(p[i].dept== "COMP.SCI"&& p[i].pname='A')
cout << p[i].prof id << endl;
cout << p[i].pname << endl;
cout << p[i].dept << endl;
}
if(flag==0)
cout << "The given details not found" << endly
return 0;
}

Output:
First Student roll no: 1
name: Brown
phone no: 123443
Second Student roll no: 2
name: Sam
Phone no : 1234567822
Third Student roll no: 3
name :Addy
Phone no : 1234567844

The Object Oriented Programming has been developed to overcome the drawbacks of procedural and modular programming. It is widely accepted that object-oriented programming is the most important and powerful way of creating software.
The Object-Oriented Programming approach mainly encourages:
1. Modularization: where the program can be decomposed into modules.
2. Software re-use: where a program can be composed from existing and new modules.
Main Features of Object Oriented Programming
1. Data Abstraction
2. Encapsulation
3. Modularity
4. Inheritance
5. Polymorphism
Encapsulation
The mechanism by which the data and functions are bound together into a single unit is known as Encapsulation. It implements abstraction.
Encapsulation is about binding the data variables and functions together in class, It can also be called data binding.
Encapsulation is the most striking feature of a class. The data is not accessible to the outside world, and only those functions which are wrapped in the class can access it. These functions provide the interface between the object's data and the program. This encapsulation of data from direct access by the program is called data hiding or information hiding.
Classes use the concept of abstraction to define a list of abstract attributes and function which operate on these attributes. They encapsulate all the essential properties of the object that are to be created. The attributes are called data members because they hold information. The functions that operate on these data are called methods or member function.
Modularity
Modularity is designing a system that is divided into a set of functional units (named modules) that can be composed into a larger application.
Inheritance
Inheritance is the technique of building new classes (derived class) from an existing Class (base class). The most important advantage of inheritance is code reusability.
Polymorphism
Polymorphism is the ability of a message or function to be displayed in more than one form.

Visibility Modes :
An important feature of Inheritance is to know which member of the base class will be acquired by the derived class. This is done by using visibility modes. The accessibility of base class by the derived class is controlled by visibility modes. The three visibility modes are private, protected and public. The default visibility mode is private. Though visibility modes and access specifiers look similar, the main difference between them is Access specifiers control the accessibility of the members with in the class where as visibility modes control the access of inherited members with in the class.
Private Visibility Mode :
When a base class is inherited with private visibility mode the public and protected members of the base class become 'private' members of the derived class.

Protected Visibility Mode:
When a base class is inherited with protected visibility mode the protected and public members of the base class become 'protected members ' of the derived class.

Public Visibility Mode :
When a base class is inherited with public visibility mode, the protected members of the base class will be inherited as protected members of the derived class and the public members of the base class will be inherited as public members of the derived class.

Software Piracy is about the copyright violation of software created originally by an individual or an institution. It includes:
(i) stealing of codes / programs and other information illegally and creating duplicate copies by unauthorized means and utilizing this data either for one's own benefit or for commercial profit.
(ii) Downloading software from illegal network sources.
An entirely different approach to software piracy is called shareware, acknowledges the futility of trying to stop people from copying software and instead relies on people's honesty.
Shareware publishers encourage users to give copies of programs to friends and colleagues but ask everyone who uses that program regularly to pay a registration fee to the program's author directly.
To prevent unauthorized access, Firewalls, Intrusion Detection Systems (IDS), Virus and Content Scanners, Patches and Hot fixes are used.