Fundamentals of Computer Part - 2
Components of a Computer
A. Input
Unit
Computer accepts data for
users through these units. It converts the instruction of users to machine
language.
The input devices are
Keyboard, Mouse, Jaystick, OCR (Optical Character Reader), Bar Code Reader,
Bio-metric Sensor, Optical disk drive, Digital Camera, Scanner, Light Pen, MICR
(Magnetic Ink Character Recognition), OMR (Optical Mark Recognition), Track
Ball etc.
B. Central
Processing Unit
The work of data
processing of the computer done this part. It is called ‘the Brain’ of
a computer. There are three parts in it.
i. Arithmetic and
Logic Unit (ALU):
It performs all
arithmetic and logic operations. ALU has two parts – Arithmetic Section
& Logic Section.
ii. Control Unit:
This unit control all the
command coming from input device. Its makes the output data. The Control
Unit directs the ALU to perform specific arithmetic and logical functions on
the data.
iii. Memory:
Its hold the input and
output resulting data. Also hold the system and application software. There are
two types of memory,
Types
Computer Memory
a) Internal Memory
(Primary): RAM, ROM
b) External Memory
(Secondary): Hard Disk, CD, DVD, Pen drive.
Permanent
Memory
It is a storable non
volatile memory. It keeps all the data which store here even when power is off.
E.g. ROM (Read Only Memory). ROM is a non-volatile memory.
- Can’t read.
- Can’t be written or changed.
- Data not lost after the power
off.
Point to Remember: ROM is where all active
programs and data are stored. So, that they are readily available and easily
accessed by the CPU.
Temporary
Memory
It holds the all active
programs data and resulting data . this type of memory easily accessible by
CPU. E.g. RAM (Random Access Memory). RAM is a volatile memory.
- Can read.
- Can be written or changed.
- Data lost after the power off.
Point to Remember: RAM is logical then that data
stored on RAM can’t be changed.
Types of
ROM
There are some qualities
of ROM
- PROM- Programmable Read Only
Memory
- EPROM- Erasable Programmable Read
Only Memory
- EEPROM- Electrically Erasable
Programmable Read Only Memory (EEPROM is used for erasing
& reconstructing the contents of ROM)
Types of
RAM
There are some qualities
of RAM.
- DRAM- Dynamic Random Access
Memory (DRAM is used for Refresh)
- SDRAM- Synchronous Random Access
Memory
- EDORAM- Extended Data Output
Random Access Memory
- NVRAM- Non Volatile Random Access
Memory
Point to
Remember: Recycle Bin is a part of Hard Disk.
C. Output
Unit
It displays the result of
processed data to the user. E.g. VDU (Visual Display Unit), Speaker, Printer,
Plotter etc.
Software
Software is set of
instructions that maintains and directs the computer to perform and process the
input information. There are three type of software,
A. System
Software
This software directs and
makes a correlation among the various hardware of a computer. E.g. Windows
XP/Vista/7/8/10, Linux, Unix, MS-Dos.
B.
Application Software
It is a specific program
defined applications. E.g. Windows Office, Paint, Games, Tally, Corel Draw,
Adobe Photoshop etc.
C. Utility
Software
It is used to debug the
error in software and correct the data through the editor. E.g. Antivirus,
PKZIP etc.
Firmware
Firmware is the
technology which has the combination of both Hardware & Software. E.g. BIOS
(Basic Input/Output system) Chip inside a computer.
