Transcript Chapter_04

Chapter No: 04
Chapter No: 04
Course Title:
IT IN BUSINESS
Course Instructor:
ADEEL ANJUM
BY ADEEL ANJUM (MCS, CCNA,WEB DEVELOPER)
1
Course Contents
Chapter No
1.
2.
Chapter Name
INTRODUCTION TO IT
INPUT & OUT PUT DEVICES
Page No
01
251
3.
SOFTWARE
117
4.
HARDWARE
117
5.
COMMUNICATIONS & NETWORKS
309
6.
INTERNET
49
BY ADEEL ANJUM (MCS, CCNA,WEB DEVELOPER)
2
3
MEASURING CAPACITY
BIT
In binary number system each 0 or 1 is
called
bit which is short for binary digit.
BYTE
A group of 8 bit is called byte and a byte
represents one character,digit,or other
value. The capacity of a computer’s
memory is expressed in number of bytes.
4
KILOBYTE
A kilobytes (KB) is about 1024 bytes.
MEGABYTE
A megabyte is about 1 million bytes or
1024 kilobytes.
GIGABYTE
A gigabyte is 1 billion or bytes or 1024
megabytes
TERABYTE
A terabyte represent 1 trillion bytes 0r
1024 gigabytes
5
1. POWER SUPPLY
The power supply is a device that
converts AC voltage to DC voltage to run
the computer.AC voltage can burn out the
low voltage DC circuitry in your computer.
6
POWER SUPPLY
7
2. UPS
A UPS (Un-interruptible power supply) is a
battery that provides a computer with
electricity if there is a power failure. The
UPS will keep a computer going for 5-30
minutes or more.
power supply unit is joule.0ne 100 joule of
energy keep a 100 watt light giving for 1
second.
8
3. BUSES
Buses are electrical data road ways
through which bits are transmitted within
cpu and between the cpu and other
components of the motherboard.
9
4. PORTS
A Port is a connecting socket into which
cables of different kind are plugged. it
allows you to connect peripheral devices
such as monitor ,keyboard, mouse
,printer ,scanner, modem etc.
we have different types of ports like serial
port, parallel ports etc.
10
11
5. MOTHERBOARD
it is main circuit board in the system unit.
it contain non removable components,
slots for components that can be
removed.
like microprocessor,RAM,Various cards
etc.
12
motherboard
13
14
6.CPU
The brain of computer is CPU.CPU stands
for central processing unit. it control
different devices. All calculations are
made inside the cpu.
PARTS OF CPU
1.control unit
2.ALU arithmetic logic unit
15
1. ALU
The arithmetic/logic unit performs
arithmetic operations and logical
operations. and controls the speed of
these operation.
arithmetic operation are addition
,subtraction,multiplication,and division.
logical operations are comparisons,
like greater than >,equal than ==, less than
< less than or equal than etc.
16
2.CONTROL UNIT
It controls the movement of electrical
signals between main memory and the
ALU.It also directs these signal between
main memory and input and out put
devices.
17
cpu
18
FUNCTIONS OF CPU
Performs all arithmetic and logical
operation in the arithmetic and logical unit
ALU
sends the result to output devices
control the activities of other units.
19
7.STORAGE DEVICE

TEMPORARY STORAGE DEVICE
1.
RAM
CACHE MEMORY
REGISTERS
2.
3.
20

PERMANENT STORAGE DEVICES
1.
ROM (read only memory)
CMOS(complementary metal oxide semiconductor)
FLOPPY DISK
HARD DISK
OPTICAL DISK
MAGNETIC TAPE
FLASH MEMORY
2.
3.
4.
5.
6.
7.
21
1.RAM
RAM (random access memory) or Primary or
main memory, temporarily hold data before it
is processed by the cpu. when you open file a
copy of file is transfer from hard disk to RAM.
when you save file it is transferred from RAM
to hard disk. RAM is said to be volatile, the
contents are lost when the power is goes off
or it is turned off.
22
RAM
23
Types Of RAM
1.
2.
3.
4.
DRAM (Dynamic RAM)
SDRAM (Synchronous dynamic RAM)
SRAM (Static RAM)
DDR-SDRAM
(Double data rate synchronous dynamic
RAM.)
24
2.CACHE MEMORY
1.
2.
3.
As cpu runs much faster than main
memory.cpu wait for instructions so to
reduce this wait we use cache. Cache is
temporary memory. It store instructions for
short time. It speed up processing.
There are three type of cache.
Level 1 cache
Level 2 cache
Level 3 cache
25
cache



Level 1
It is part of processor also called internal
cache. its size is 256 kb.
Level 2
it is out side processor not part of processor it
is also called external cache. its size is 2 MB.
Level 3
it is on motherboard near ram.
26
3.REGISTER
Register are high speed storage areas that
temporarily store data during processing.
for example ,if two numbers are multiplied
both number must be in register and
result is also placed in register.
27
1.ROM
ROM read only memory cannot be written
on or erased by the computer user
without special equipment.ROM chips
contain fixed start up instruction. the
contents of ROM are permanent.
28
2.CMOS MEMORY
complementary metal oxide semiconductor
chips are power by a battery and thus do
not lose their contents, when the power is
turned off.
CMOS Chips contain instruction such as
time,date,calender.unlike ROM chip CMOS
chip can be reprogrammed as when you
need to change. your system software
allow you to change time and date stored
on CMOS.
29
3.VIRTUAL MEMORY
virtual memory is some free space on
hard disk, it is used to extend RAM. The
processor searches for data in this order
first in level 1 cache then L2 cache then
L3 cache then main memory then virtual
memory. then hard disk.
30
4.FLOPPY DISK
It is removable flat plastic case which
store data permanently. it store about 1.45
mega byte data. Super disk can store 120
megabyte.
31
32
5.HARD DISK
Hard disk provide a very big storage
capacity and are very fast. it store data
permanently. it consist of metal platter
fixed on vertical spindle. platter is coated
with magnetic material on which data is
recorded
33
6.OPTICAL DISK
An optical disk is removable disk which
store data permanently. To read data laser
light is used. Pitted area are not reflected
and are interpreted as 0 bits smooth area
are reflected and are interpreted as 1 bits.
Example:
CDs (compact disks)
DVDs (digital versatile disk)
34
35
7.FLASH
Flash is non volatile memory. it holds up
to 4 gigabyte of data.
example USB universal serial bus, also
called flash drive or keychain drive.
36
37