What is Computer?
A computer is an electronic device that accepts the data as an input, operates on data based on the instructions stored in memory and generates the output. The general representation of the computer is shown below:
Some Important Computer parts:
A computer is made up of two components:
- Hardware and
Computer hardware is a physical device made up of electronic components such as registrars, transistors, capacitors etc.
The software is a collection of programs that allow hardware to serve its purpose. The purpose of the software is to use built-in hardware components.
The computer’s essential hardware components are:
- CPU (central processing unit).
- I / O (input / output) device.
Central Processing Unit (CPU):
CPU is the main hardware component of a computer. It is responsible for arithmetic calculation, the comparison between the data and the movement of data inside the system, such as movement.
The Central Processing Unit consists mainly of two components:
- Arithmetical Logical Unit (ALU) and
- Control Unit (CU).
Arithmetic Logical Unit:
ALU performs arithmetic and logical operations on data based on the instructions stored in memory.
Control unit: Control unit (CU) coordinates system components, such as transfer of data between components, time etc.
Memory: Memory is where the program and data are stored temporarily during processing. There are two types of memory in the computer system.
- Main memory or primary memory and
- Supportive memory or secondary memory.
This is where programs and data are stored temporarily during processing. When we shut down the computer or when we log off, data is erased in the main memory.
Supporting memory: This memory is where the program and data are stored permanently. When we shut down the computer, our programs and data live in the secondary storage, the next time we need them.
I / O device: Input device allows the user to give the data as input to the computer and the output device allows the computer to show information to the user. Examples of input devices are keyboard, mouse and scanner.
Hardware component inside the computer
The motherboard is the most important hardware component of the computer. The motherboard is a hardware component that puts together other hardware components as one another. A PC’s motherboard, or mainboard, is a large circuit board that is home to many of the most essential parts of a computer such as a microprocessor, chipset, cache, memory socket, bus, parallel and serial port, mouse and keyboard connector, hard disk and floppy Disk socket etc.
The microprocessor or processor or central processing unit is the heart of every computer. It is designed to perform all the mathematics, logic and other basic computing steps that make up the functions of your computer.
Whenever a user executes a word processor, computer game, browser or any other software program, the CPU also does hundreds or thousands of instructions. The microprocessor is a piece of electronic circuits that use digital logic for software instructions.
A microprocessor is an integrated circuit – a thin piece of silicon crystal packed with microscopic circuit elements: wire, transistor, capacitor, resistant etc.
Random Access Memory (RAM)
Random Access Memory (RAM) is used to store data, instructions, which are accessed by the CPU for execution. Ram is also known as main memory or primary memory. Data or instructions stored on the RAM can be accessed randomly. Hence the name Random Access RAM is known as an unstable memory device after the computer is switched off or the power is off, the data stored on the RAM is erased.
RAM is of two types, i.e.
- Static RAM (SRAM) and
- Dynamic RAM (DRAM).
SRAM:- Electronic components used in SRAM are flip-flops. Flip-flop size is usually larger than other electronic components such as capacitors and transistors. Therefore, the size of the SRAM is smaller than the DRAM. Saram is faster than DRAM. DRAM is made of capacitors and transistors.
DRAM:- To maintain the data, DRAM needs to be refreshed at regular intervals. Therefore, the DRAM is slow compared to SRAM. DRAMs are available in larger sizes than SRAM. Widely used RAM nowadays is DDR SDRAM (Double Data Rate Synchronous Dynamic Random Access Memory). There are various types of RAM in this type: DDR2 SDRAM and DDR3 SDRAM.
Read only memory (ROM)
There is only one non-volatile memory in the memory computer. It is used to store firmware (software that is tightly tied to the hardware). Since the name implies that this memory can be read only and stored on it.
There are only two types of memory:
- Mask ROM and
- Non-mask ROM.
Mask ROM:- Mask ROM has been programmed before being available in the market. Once they have been purchased, they can not be programmed again.
Non-Mask ROM:- Non-mask ROM can be programmed again even after being purchased from the market. There are three types of non-masked follicles. They are:
- Prom (Read Only Programmable)
- EPROM (irrespective programmable read-only memory)
- EEPROM (Read removable electronics removable programmable only)
PROM: Programmable read-only memory (prom) or once programmable ROM (OTP), also called prom programmer, can be written through a special device. Prom can be programmed only once.
EPROM: This type of memory can be erased by exposing it to strong ultra-violet rays. These ROMs can be programmed multiple times. With constant contact of UV rays, Rome is worn and it will be made unusable.
EEPROM: This type of permit allows for erasing and rebuilding electronically selected banks of entire Rome or memory. There is no need to remove EEPROM for programmed from the motherboard. EEPROMs can be programmed again many times.
Rome has to store the data permanently. The data should not be erased when the computer stops or power is switched off. To help Rome store its data permanently, there is a CMOS battery in the motherboard, which gives Rome continuous power.
Secondary memory or helpful memory:
Secondary memory is not directly available by the CPU. The secondary memory of the computer includes a hard disk, floppy disk, CD, DVD, Blu-ray disc, pen drive, SD card, tape device and other types of USB memory devices. Secondary storage is used to store data permanently. Secondary memory is the non-volatile memory.
When the primary memory (RAM) is filled with data and instructions, and there is no memory to allocate in RAM in the new process, then the CPU changes at least the recently used memory on memory and Allocates space in the new process. In memory of Ram, a memory is used as a primary memory, which is known as virtual memory. When virtual memory is used by the CPU, it takes the data out and out in virtual memory, which is usually slowed by accessing data from the RAM. Therefore, when virtual memory is used, then the performance of the system gets spoiled.
Floppy disks or diskettes are an example for secondary memory. It is usually available in 3.5 inches and 5.25 inches sizes. In the olden days, the floppy disk was the primary data storage device on the PC, but later it played the role of removable media for a small collection of files or files