CHAPTER-1
COMPUTER SYSTEM
Name- Bhavya Agrawal
Class- 11thComm.
Submited to- Apurv Sir
INTRODUCTION
Computer:- Computer is an electronic
device which is used to manuplate the
data.
Computer System comprises of two parts:
 Hardware
 Software
I.P.O. CYCLE
I.P.O. stands for Input Process Output
 It receives the input from the user and after
processing, it gives the desire output.
DATA
Input
PROCESS
STORAGE
Output
INFORMATION
INPUT DEVICES
An INPUT UNIT fetches the input and
converts it into binary form which is directly
understood by the computer.
There are many types of Input Devices as
follow:KEYBOARD:- It directly enters the data in the
form of letters, digits, commands into the
computer.
MOUSE:- It is a pointing device with a roller at
its base, used for pointing on a computer monitor.
LIGHT PEN:- It is a pointing device that can
be used to select anything on the computer
screen simply by pointing at it.
OMR:- It stands for Optical Marker Reader. It
is capable of recognizing a pre-specified type
of mark made with a dark pencil or ink.
BAR CODE READER:- A machine which is
used to read the barcode is called Bar Code
Reader.
SCANNER:- It is an electronic machine that
can look at, send images or electrical
information.
OCR:- Optical Mark Recognisation.
It recognizes text within a digital image.
Used in scanned document and images. It
converts physical paper document into
electronic version with text.
OUTPUT DEVICES
Plotter:- It is a printer that interprets commands
from a computer to make line drawings
on paper with one or more automated pens.
Monitor:- It is an output device which is
used to display information in pictorial or
textual form.
LCD:- It stands for Liquid Crystal Display. It is a
type of flat panel display which uses
liquid crystals in its primary forms.
CENTRAL
PROCESSING UNIT
 CPU is a control center or brain of a computer.
 It consists of three components:ARITHMETIC LOGICAL UNIT (ALU)
CONTROL UNIT (CU)
REGISTERS
ALU:It stands for Arithmetical and logical unit.
It is used to carry out arithmetical instructions
like addition(+), subtraction(-), etc and logical
units like <, >, = .
CU:It stand for Control Unit.
It is used to control the processing of the
computer.
REGISTERS:They are high speed temporary storage areas
found in the C.P.U.
MEMORY UNIT
They are of two types:Primary unit
Secondary unit
PRIMARY UNIT:- It is the internal volatile
memory where data and instructions are
stored.
SECONDARY UNIT:- It is an external memory
which is used to store the data permanently.
PARTS OF PRIMARY UNIT
Random Access Memory (RAM)
Read Only Memory (ROM)
RAM:- The memory cells can be exist for
information transferred from any desire random
location. It is volatile in nature as when power
goes off, content gets deleted.
Types:- DRAM, SRAM
DRAM:- These are made up of transistors
and capacitors. The amount of time taken to
produce data required for memory,
from the start to excess until the
availability of data in all memory on time.
DRAM access time is btw 20-70 nano-seconds.
SRAM:- It stands for Static Random Access
Memory. They are made up of flip
locks and offers faster access time
about 10 nano-seconds.
ROM:- It stands for Read Only Memory.
It only performs the react operations and
Does not have the right capabilities.
There are various types of ROM:PROM
Flash ROM
EP-ROM
EEP-ROM
SECONDARY MEMORY
Hard Disk:- It is the secondary storage device
and used to store all the programs and data on
the device.
Compact Disk:- It is an optical device used for
storing digital data. They have 700 Mb of
storage.
Digital Versatile Disk:- It is also an optical disk
but faster then CD. It can hold 4.7 Gb to 17Gb
of data.
Blue-Ray Disk:- It is also an optical storage
device but use blue violet lase instead of a
red laser beam to store. It can sore up to 25 Gb
of data.
Types of Software:- System software
:- Application software
SYSTEM SOFTWARE:- It is a software that
controls internal computer operation.
Types of System Software
Operating System:- It is a type of program
which acts as an interface between a user and a
computer. E.g. :- Windows, Mac OS, etc.
Command Based Interface:- It provides the
user to type command to instruct the
operating system to perform the desire action.
E.g. :- Docs
Generating User Interface:- It is a type of user
interface that allow the user to interact with the
computer through images rather than the text
command. These images can be in the form of
icons, value at other option.
E.g. :- GUIR
Touch Based Interface:- These type of
interface accept input as touch as like the
mobile operating system. E.g. :- 8.1 windows
Voice Based Interface:- In this type of
interface, we don’t need any input unit like
mouse, keyboard, etc. They use only voice
commands to make a computer work in the
desired way.
Gesture Based Interface:- In this type of
interface, user interact with the device using
gesture slide, eye contact, shaking, etc. This
technology is involving faster and it has
promising potential for application mobile
gaming.
NEED FOR OPERATING SYSTEM
It provides user interface.
Programming execution.
Resource allocation
Manipulating of full system
Input / Output System
Input Operation
Error Detection
FUNCTIONS OF OPERATING
SYSTEM
Resource management
Process management
Memory management
File management
Device Management
Language Translator
Assembler:- It is used to translate the program
written in assembly language to machine
language.
ASSEMBLER
SOUCE
CODE
ASSEMBLER
OBJECT
CODE
Compiler:- The language processor that
process the complete source program as a
whole in one go into machine language is called
compiler.
E.g. :- Compilers of C and C++
Interpreter:- The language processor that
translates a single statement at once into
machine language and execute it immediately
before moving on to the next line.
Application Software
Application software are bought by the user to
perform applications or task.
They are of two types:General Purpose Application Software(GPAS)
Specific Purpose Application (SPA)
SPAS / Customized Software
This software is one which is tailor made as
per the user requirement. Such type of software
is customer specific.
UTILITY SOFTWARE
They are those application programs that
assists the computer by performing housekeeping functions like searching, removing
viruses, etc.
Examples of Utility Software
Backup Utility:- This utility helps in taking
backup of data, i.e., duplicating the disk
information. It creates a copy of complete or
partial data store in a disk or other external
device.
Anti-Virus Software:- It is a utility software
which detect and remove computer viruses
infected areas from the computer hardware for
smooth functioning.
E.g. :- Nortan, Abg, etc.
Device Drivers:- It is a program that controls a
particular type of device that is attached to
the computer. This device driver provide the
familiar environment to the new device for the
smooth working.
Thank you