Computer: Basic Introduction
What is a computer?
People often think of a computer as a powerful
superhuman, but that is not the case. It is simply an automated electronic
machine that works at a fast pace and does not make mistakes. Its capacity is
limited. It is derived from the English word "compute," which means
to calculate. In Hindi, it is called a "sanganak." Its use is to
process and gather a lot of information.
A computer is a device that collects data and processes it according to software or a program to produce a result.
The computer is defined as artificial intelligence. Its memory power is higher than that of humans.
Elementary words
relating to the computer
• 1. Data: It is unorganized figures or facts. It is the initial stage of processing. Generally, data is divided into two parts.
(a) Numerical Data: This type of data consists of numbers from 0 to 9, such as employees' salaries, exam scores, census data, and numerical calculations.
(b) Alphanumeric Data: This type of data includes a combination of numbers, letters, and symbols, such as addresses.
2. Information: This is the organized result obtained after processing unorganized data.
Characteristics of
Computer
A. It operates at high speed, thus saving time.
B. It operates without errors.
C. It provides permanent and extensive storage capacity.
D. It is capable of making rapid decisions according to predefined instructions.
A.
Uses
of Computer:
a. In the field of Education
b. In Scientific Research
c. In Railway and Airlines Reservation
d. In Banks
e. In Medical Science
f. In the field of Defence
g. In Publication
h. In Business
i. In Communication
j. In Administration
k. In Recreation
§
Functions of Computer:
A. Data Collection
B. Data Storage
C. Data Processing
D. Data Output
Data Processing &
Electronic Data Processing:
Before the invention of computers, data collection, storage, processing, and output were done manually to achieve specific goals, which were known as data processing. As technology developed, computers began to be used for all these tasks, known as Electronic Data Processing (E.D.P.).
The main goal of data processing is to obtain organized information from unorganized data (Raw Data), which is used for decision-making.
Computer System:
It is a group of devices that work together to process data. A computer system has several units used in electronic data processing. The basic computer processing cycle includes input, processing, and output:
1. Input Unit: A unit that receives data from the user and transmits it to the Central Processing Unit in the form of electronic pulses. For example, when we go to withdraw money from an Automatic Teller Machine (ATM), we have to enter a Personal Identification Number (PIN). A keypad is used as the input unit for this purpose. GIGO (Garbage in, garbage out) is a concept in computer science that states the accuracy of the output depends on the accuracy of the input.
2. Central Processing Unit (CPU): Also known as the processor, it is an electronic microchip that processes data into information. It is referred to as the 'brain of the computer' and controls all functions of the computer system, converting input into output. Together with the input and output units, it forms the complete computer system.
Instruction Cycle: The basic operation process of any computer is also called the Fetch-Decode-Execute cycle. During this process, the computer retrieves program instructions from its memory and performs tasks as directed. This process continues from bootup until the computer is shut down.
Each computer's CPU may have different cycles based on different instructions, but the following are almost the same:
1. Fetch the instruction: The CPU retrieves the instruction from the memory address and places it in the instruction register. The program counter is then set to the address of the next instruction.
2. Decode the instruction: The encoded instruction in the instruction register is interpreted by the decoder.
3. Execute the instruction: The control unit of the CPU sends signals to the ALU to perform mathematical or logical operations, retrieve values from registers, and return the results to the registers. This cycle is repeated.
Central Processing
Unit:
(a) Arithmetic Logic Unit (ALU):
Used for arithmetic and logical calculations. Arithmetic calculations include addition, subtraction, multiplication, and division, while logical calculations include comparative operations such as less than, greater than, or equal to, and yes or no decisions.
(b) Control Unit:
Controls all operations of the computer and coordinates activities between all
parts
of the computer, such as input, output
devices, and processors.
(c) Memory Unit: Used for storing data and instructions. It is mainly divided into two categories: primary and secondary memory. Primary memory (registers) stores data and instructions currently in use. Secondary memory is used to store data and instructions for later use.
3. Output Unit: This is the unit that takes data from the Central Processing Unit and converts it into a form understandable by the user. For example, when we pay the bill at a supermarket, we receive a receipt, which is a form of output. This output is obtained from an output device like a printer.