6
Expected Etiquettes
o You
shall
now
become
a
professional person. Demonstrate
behavior of a professional.
o Make yourself your parents and
then the organization proud with
your conduct and achievements.
o You will require class attendance
REGULARLY otherwise you shall
struggle to understand this subject.
Attending classes is for your own
good.
o Graphic Era lab exams of a very high
standard. You are expected to run
the code and answer viva-voice
questions.
7
Expected Etiquettes
o Very, Very important to learn
programming basics to secure a
good life and job.
o Execute the code on a
computer/smart phone then only
your understanding shall increase.
o You need to bring to my attention
any issues regarding the course at
the earliest to the attention of your
class teacher, anything you feel
should be looked into.
o Show professional behavior to your
teachers.
8
Words of positive Advice
o Stress, Emotional problems. Feel free
to contact your faculty. They shall help
you connect to resources.
o For God’s sake stay away from Drugs
and other harmful substances.
9
*****
1
Introduction to Computers
o Introduction to Computers
o Software & Hardware
o Input / Output Devices
o Computer memory
o RAM/ROM
o Understand bit, byte, KB, MB, GB
and their relations to each other
o Generation of computers
o Operating System
o Computer Networks
2
What is a Computer ?
RAW DATA
I NFORM ATI ON
COM PUTER
I NPUT
OUTPUT
PROCESSI NG
• Computer is an electronic machine
that takes in raw data as input,
processes it and gives out useful
information as output.
o A computer is a machine that takes
instructions and performs operations
based on those instructions.
3
Why use Computers?
• Increases the productivity and
efficiency.
• Can crunch data at lightning speed
• Can store vast amounts of data
• Helps sort, organize, and search
through information.
• Connects to the vast world of
information thru the Internet.
• Get a better understanding of data.
• Can help in making a decision using
the vast data.
6
Some Applications of Computers
 Word Processing
 Internet
 Digital Audio or Video Composition
 Desktop Publishing
 e-Business
 Bioinformatics
 Health care
 GIS and Remote Sensing
 Meteorology
 Multimedia and Animation
 Legal System
 Retail Business
 Video Games
 Entertainment
 Sports
1
Software & Hardware
COMPUTER
HARDWARE
SYSTEM
SOFTWARE
SOFTWARE
APPLICATION
SOFTWARE
SOFTWARE
UTILITIES
o Broadly the electronic circuitry is called
the Hardware and programs and data
the Software.
o The Software is instructions in form of
programs along with data manage the
computer system and control the
hardware components.
Example:
The antivirus, chrome browser, Linux
OS that protects the computer system
is a type of Software.

2
Hardware and Software both Necessary
 The computer on its own is of no use.
 The hardware needs a software (a set
of programs & data) to instruct what
has to be done.
 A program is a set of instructions that
is arranged in a sequence to guide a
computer to find a solution for the
given problem.
 The process of writing a program is
called programming.
Computer software is written by computer
programmers
using
a
programming
language.
Examples of computer software include:
 Browsers, Windows, Linux
 Computer Games
3
* Courtesy ASUS
*
4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Birds Eye View of PC Hardware
Scanner
CPU (Microprocessor)
Main memory (RAM)
Expansion cards
Power supply unit
Optical disc drive
Hard disk drive (HDD)
Motherboard
Speaker
Monitor
System software
Application software
Keyboard
Mouse
External hard disk
Printer
***
/* Most Humbly and Gratefully Acknowledge to all the Wonderful People making
Content Freely Available
Description : A stylized personal computer, with as many parts as possible
shown and labeled
Link :
https://commons.wikimedia.org/wiki/File:Personal_computer,_exploded_6.svg
License Type: Creative Commons Attribution 2.5 Generic license.
Author: User:HereToHelp
*/
* ASUS Motherboard used for representational purpose only. Image credits ASUS.
5
Computer
Hardware
represents
the
physical and tangible components of a
computer, i.e. the components that can be
seen and touched.
 Examples of Hardware are the following
 Input devices − keyboard, mouse, etc.
 Output devices − printer, monitor, etc.
 Secondary storage devices − Hard disk,
CD, DVD, etc.
 Internal components − CPU,
motherboard, RAM, etc.
6
Types of Software's
• Depending on function and application
desired, Software can be divided into
three major types:
– System Software
– Application Software
– Utility Software
7
System Software
Application Software
It is a collection of
programs that
enable the users to
interact with
hardware
components
efficiently
It is a collection of
programs written for
a specific
application. Like, we
have library system,
inventory control
system, etc
It controls and
manages the
hardware
It uses the services
provided by the
system software to
interact with
hardware
components
System software is
machine dependant
It is machine
independent
8
System Software
Application Software
The programmer
must understand the
architecture of the
machine and
hardware details to
write a system
software
The programmer
ignores the
architecture of the
machine and
hardware details to
write an application
software
Interacts with the
hardware directly
Interacts with the
hardware indirectly
through system calls
provided by system
software
Writing a system
software is a
complicated task
Writing application
programs is relatively
very easy
Example: compiler,
operating system
Example: MS-WORD,
PAINT
1
Block or Functional Diagram of a
Computer
A computer is an electronic device which
basically performs five major functions
namely…
o accepts data or instructions (input) via
Input Devices
o stores data (Primary and Secondary
Memory)
o process data (via CPU)
o displays results (output) (via Output
Devices)
o controls and co-ordinates all operations
inside a computer (via Control Unit)
2
3
WorkStation / Server
** All images courtesy ASUS computers
computers. Images for representational purpose only.
4
Functional Block Diagram of a Computer
*****
8
Software Utilities
Utility software is software designed to
help to analyze, configure, optimize or
maintain a computer. It is used to support
the computer infrastructure - in contrast
to application software, which is aimed at
directly performing tasks that benefit
ordinary users.
Anti-virus utilities scan for computer
viruses and block or remove them.
Diagnostic programs determine and
report the operational status of
computer hardware and software.
Memory testers are one example
Cryptographic utilities encrypt and
decrypt streams and files.
9
Backup software makes copies of all
information stored on a disk and restores
either the entire disk (aka Disk cloning)
in an event of disk failure or selected
files that are accidentally deleted or
corrupted. Undeletion utilities are
sometimes more convenient.
Data conversion utilities transform data
from a source file to some other format,
such as from a text file to a PDF
document.
10
Operating System
 The primary goal of an operating system
is to make the computer system
convenient and efficient to use.
(Computer Usable)
 An operating system ensures that the
system resources (such as CPU, memory,
I/O devices, etc) are utilized efficiently
i.e. Resource Manager.
For example, there may be many service
requests on a web server and each user
request need to be serviced. Similarly, there
may be many programs residing in the main
memory.
Therefore, the system needs to
determine which programs are active and
which need to wait for some I/O operation.
11
12
Functions / Objectives of Operating
System
o Manages the computer hardware
o Process Management
o Memory Management
o I/O Device Management
o File System
o Protection / Security
o Network Management
o
Network Services (Distributed
Computing)
o
User Interface.
13
Examples of Operating System
 MS DOS System
 Windows Operating System
 UNIX
 LINUX
 Mobile Operating Systems
iOS, Android, Windows Phone ,
BlackBerry OS
** Students can find out about Open Source Software and
Commercial Software with examples.
 Freeware, Free Software, License etc
*****
1
Modern Electronic Computer
Architecture
Von Neumann Architecture
2
Von Neumann Architecture or the
Princeton Model
Proposed design architecture for an
electronic digital computer with these
components:
o Processing unit contains arithmetic
logic unit and processor registers
o Control unit that contains an instruction
register and program counter
o Main Memory that stores data and
instructions
o External mass storage. Secondary
device.
o Input and output facility
Also referred to as stored-program digital
computer keeps both program instructions
and data in read–write, random-access
memory (RAM)
3
Intro to Computer Memory
Computer’s memory is used to store
data and programs. Two Major types
o Primary or Main memory
o Secondary or Auxiliary memory
MAIN MEMORY:
Instructions and
data of a program in execution.
Volatile, so retains content when
power is on. Additionally, is expensive
and limited in capacity.
SECONDARY MEMORY: Data and
programs not currently in use. Place
of permanent data storage.
4
Secondary memory
o Data and/or instructions stay
permanently. Not reliant on power.
o Cheaper and can store very large
data quantity.
o Certain device like pen drives etc
data is portable, copied from one
machine to another.
o Slower speed of access compared to
main memory.
o Memory is organized into a number
of partitions called as cells. Each cell
has an address. Just like a housing
colony.
5
Primary Memory (Main Memory)
 Contains data and instructions the
computer is currently processing.
 Very less capacity compared to
secondary memory. Example Hard
Disk 1024 GB, main memory generally
4 to 16 GB
 Made up of semiconductors.
 Very fast compared to secondary
memory but slower than Internal CPU
memory (Registers).
 Volatile, and Required for program
execution.
6
Types of RAM
Static RAM (SRAM)
 Flip Flop (latch) is used to represent 1
and 0’s
 The word static indicates memory
refresh is not required. Simpler Design.
 Faster and Used as cache memory
 Highly Reliable
 Expensive and Long life
 Finds use in digital Cameras, high end
mobile phones.
** Image courtesy of Hyundai. Used for representational purpose only.
7
Dynamic RAM (DRAM)
 Consists of a Capacitor and Transistor
Combo.
 Capacitor gradually discharges. Must be
continually refreshed in order to
maintain the data.
 Done by a refresh circuit that rewrites
the data several times per second.
 As it is cheaper, smaller, higher
capacity, forms major part of Main
memory.
 Short data lifetime
 Slower as compared to SRAM
 Used as RAM
 Smaller/Denser in size, Less expensive
 More power consumption
** Image courtesy of Samsung. Used for representational purpose only.
Samsung 16GB
8
Read Only Memory
 ROM stands for Read Only Memory.
Data stored in ROM also known as
firmware.
 Generally used in PC to store
instructions needed to Boot-up** a
computer.
 Non-volatile.
Information
programmed/stored permanently
such memories
is
in
ROM extensively used in electronic items
like
washing
machine,
Dishwasher,
Cameras and microwave oven among
others.
** ROM Role in Computer Booting Process
subsequent video
9
Types of ROMs and their characteristics
MROM (Masked ROM)
 Hard-wired* devices that contain preprogrammed set of data or
instructions.
PROM (Programmable Read Only
Memory)
 PROM can be modified only once by
the user/manufacturer.
 It can be programmed only once and
is not erasable.
EPROM (Erasable and Programmable
Read Only Memory)
 EPROM can be erased by ultra-violet
light.
* Electronic circuitry that is designed to perform a specific task.
10
EEPROM (Electrically Erasable and
Programmable Read Only Memory)
 EEPROM is programmed and erased
electrically.
 Can be erased and reprogrammed about
ten thousand times.
 Selective location can be modified and
programmed.
 They can be erased one byte at a time,
rather than the entire chip.
13
Sequential Data
Access
Random Data
Access
To reach a specific
data item all items
prior to it need to be
traversed.
Irrespective of the
location of the data
element, time taken
to reach it is a
constant for that
media
Examples: Magnetic Main Memory (RAM)
Tape, Old Cassette
players
Devices are more
Expensive and
economical and
lesser capacity
generally have more
capacity
Depends upon
Searching for a
application:
particular employee
Example processing information
salary of each
employee
14
Sequential vs Random Access
/* Most Humbly and Gratefully Acknowledge to all the Wonderful People making Content Freely Available
Description : File:Random vs sequential access.svg
Link : https://commons.wikimedia.org/wiki/File:Random_vs_sequential_access.svg
License Type: I, the copyright holder of this work, release this work into the public domain. This applies
worldwide.
Author: Me (User:Intgr)
*/
18
Secondary Memory /Auxiliary Memory
 Known as external memory
 Slower than the Primary memory.
 Stores data/information permanently.
 Huge Capacity based on need
 Cost per unit of storage is cheaper
compared to RAM
 CPU can utilize secondary memory
only when the contents are moved to
the RAM.
 Devices are highly stable and Reliable
 Data permanent till deletion
 Modify, Delete data
Example: Hard disk, CD-ROM, DVD,
Pen Drive etc.
19
HARD DISK
o Thought of as Circular plates (called
as platters) stacked upon each other
with suitable gaps.
o Platters coated with magnetic
medium for data recording.
20
Hard Disk Drive
/* Most Humbly and Gratefully Acknowledge to all the Wonderful People making Content Freely Available
Description : Diagram of a computer hard disk drive
Link : https://commons.wikimedia.org/wiki/File:Hard_drive
https://commons.wikimedia.org/wiki/File:Hard_drive-en.svg
License Type: Creative Commons Attribution
Attribution-Share Alike 3.0 Unported license.
Author: Surachit
*/
21
Platter Structure
track (A), a geometrical sector (B),
(B) a
track sector (C) and a cluster of sectors
(D).
/*
Most Humbly and Gratefully Acknowledge to all the Wonderful People making Content Freely Available
Description: Disk structure showing a track (A), a geometrical sector (B), a track sector (C) and a
cluster of sectors (D). The term "sector" in the context of computer engineering usually refers to
(C).
Link: https://commons.wikimedia.org/wiki/File:Disk
https://commons.wikimedia.org/wiki/File:Disk-structure2.svg
Author: Heron2/MistWiz
License Terms: I, the copyright holder of this work, release this work into the public domain. This
applies worldwide.
*/
22
Hard drive geometry cylinder/head/sector
/* Most Humbly and Gratefully Acknowledge to all the Wonderful People making Content Freely Available
Description : hard drive geometry - cylinder/head/sector (per track) (CHS)
This is an information graphic about a common early method for giving addresses to each physical
block of data on a hard disk drive.
Link : https://commons.wikimedia.org/wiki/File:Hard_drive_geometry_
https://commons.wikimedia.org/wiki/File:Hard_drive_geometry_-_English_-_2019
_2019-05-30.svg
License Type: Creative Commons Attribution
Attribution-Share Alike 4.0 International, 3.0 Unported,
orted, 2.5
Generic, 2.0 Generic and 1.0 Generic license
Author:
Henry Mühlpfordt, png version from 2010: Bagok */
16
Bits, Nibble, Bytes
Bit (Binary Digit)
0 or 1 in binary system
Nibble
Group of 4 bits.
Byte
8 bits is called byte.
Word
A computer word represents
number of bits processed as
a unit. Can vary from 8 bits
to 64 bits to even more.
17
Typical Memory Units Encountered
Seq. #
Name
Size
1
Bit
1 bit
2
Nibble
4 bits
3
Byte
8 bits
4
Kilobyte (KB)
1024 bytes
5
Megabyte (MB) 1024 KB
6
Gigabyte (GB)
1024 MB
7
Terabyte (TB)
1024 GB
21
Cache Memory
 Challenge is CPU is extremely fast. RAM
is unable to cope up with CPU speed.
 Solution Cache memory. Placed
between CPU and RAM
 CPU looks for Instructions and Data
FIRST in Cache memory then to RAM.
 Cache memory much faster than RAM.
 Made up of expensive SRAM (Static
RAM)
 Very very small compared to RAM
 Key concept is to HOLD frequently
used data and instructions to provide
faster access to CPU.
22
Cache Memory Conceptual Diagram
* Temporal & Spatial Locality
23
Understanding Temporal and Spatial
Locality
number [5]
Location
Value
0
1
2
3
4
45
65
99
0
33
Keep adding number from location 0 to
location 4 to sum
{
sum = sum + number [ i ]
i
=i+1
}
// i = 0 , 1, 2, 3, 4
15
Computer Memory Hierarchy
1
Computer Languages



Machine Language
Assembly Language
High Level Language
Machine Level Language
o Program is a set of instructions
o Instructions executed by the CPU
using data to achieve an objective
o CPU
fetches
an
instruction,
decodes or figures it out and then
executes the instruction
o Binary means ON/OFF represented
by 1s and 0s
Please do some discovery as to why binary numbers are used in
computers. Later on in the comments section, the best answer shall be
put on top by me with my comments if required.
2
Machine Level Language (cont’d)
o Instructions are written in terms of
1s and 0s only
o Differs from Computer to Computer
based on hardware architecture
o Fastest execution & Efficient Code
o Extremely difficult to write
o Can make mistakes
o For example
Stop 0000
Start 0001
Error 1111
Add 1010
https://chortle.ccsu.edu/java5/Notes/chap04/ch04_4.html
(Nice example of a machine language Code)
 Binary devices are Simple and easy to build.
 Binary signals are Unambiguous (which gives them noise immunity).
•
•
•
•
Word Size
Number of Registers
Little Endian Big Endian
Harvard vs. Von Neumann
3
Assembly Language
o Uses Mnemonics (symbols to
represent) Opcode (instructions)
o Therefore human readable,
understandable compared to machine
language
o For example
0000 STOP
0001 Start
1111 Error
1010 Add
o Start, Stop, Error, Add are all examples
of Mnemonics
o Considered low level programming
language
o Needs Software called as Assembler for
conversion
o Still used critical parts. Code runs fast.
o Highly dependent on the computer
architecture
4
High Level Language (HLL)
o Uses English like language
o Simpler to write code compared to
Assembly or machine language
o Knowledge of Hardware not required
o Needs software tools like Compiler to
transform to machine code
o Faster development and completion of
coding tasks
o The nature of HLL permits code to be
used
across
different
machines
without major changes.
o Code written is generally portable and
hardware architecture Independent.
o Examples: FORTRAN, COBOL, C, C++,
JAVA etc
o C Compilers generate code comparable
to assembly language
5
Hardware, Machine Language,
Assembly Language and High Level
Language Relationship
6
Translators





Assembler
Compiler
Interpreter
Linker
Loader
Need for Translators and Support Tools
o Computers understand only machine
language
o Support system software’s to take a
program in high level language and
help it execute on a given machine
Assembler
o System program that transforms code in
Assembly language to Machine language
(object code)
Assembly Language
MOV A, B
Machine Language
0010 1100 0011
7
Compiler
Translates a computer program
written in a high level programming
language to an executable for a
target machine. i.e. Source Code to
Assembly or machine code.
High Level Language
A=B
Assembly Language
MOV A, B
Machine Language
0010 1100 0011
Example: GNU C Compiler
8
Interpreter
o Reads a program in high level language
and executes the instructions without
having to compile the program first.
o Takes a line of source code and executes
that line. Then proceeds to do the same
with the subsequent line.
Examples: Python, PERL, BASIC
languages
9
Compiler vs Interpreter Major Differences
Compiler
Interpreter
Translates the entire
program into
machine code and
then allows linking
and loading for
execution.
Compiled program
runs faster
Produces complete
error/warning list
Converts one line of
the source program
and then executes
that line. Proceeds to
the next statement in
this manner.
Comparatively slower.
Compile once run
many times
Source code required
each time.
Ex: C, C++
JAVA, Python etc
Halts at the first error.
10
Linker
o Referred alternatively as binder, link
editor
o Let us say we write some code that uses
SQRT code already available.
o Linker joins or patches your code with
the externally available code, libraries.
o Combines the output of a compiler or
assembler to a single executable file.
11
Loader
o
o
o
Executable
program
from
the
secondary memory needs to be loaded
into the RAM (main memory) for the
CPU to execute the code.
Verifies memory permissions
permissions,, memory
availability etc
Hands over to the CPU the starting
address for execution.
12
*****
1
Generation of computers
Background
o We live in an information age or the
age of Computers
o Younger generation bought up in this
age
needs
to
develop
an
understanding and appreciation of
computer technology evolution over
a period of past 70-80 years
o Broadly
classified
into
five
generations of development based
on technology improvement, faster
processing ability, and smaller size,
more reliable, efficient, cheaper and
capable of doing more things.
o Over a period of time they have
moved from Corporations to homes
to all around.
2
First Generation – Vacuum Tubes
(1940 to 1956)
o Vacuum Tubes Based Circuits
o Magnetic Drums For Memory
o Enormous Size Filled Many Rooms
o Consumed lot of electricity, Generated a
lot of heat, and as a result excess of
heat suffered Regular Breakdowns.
o Machine language (Direct
Communication with Computers)
o Handled only one task at a time
o Input was based on punched cards and
paper tape
o ENIAC (Electronic Numerical Integrator
and Computer machines)
3
o UNIVAC (Universal Automatic
Computer) the first every commercial
computer purchased in 1951 by the US
Census Bureau
Link: https://commons.wikimedia.org/wiki/File:Used_Punchcard_(5151286161).jpg
License : This file is licensed under the Creative Commons Attribution 2.0 Generic license.
Author : Pete Birkinshaw from Manchester, UK
Description : This card was used to load software into a mainframe computer. Each byte (the letter 'A', for
example) is entered by punching out a column of holes.
Link: https://commons.wikimedia.org/wiki/File:PaperTapes-5and8Hole.jpg
License : I, the copyright holder of this work, release this work into the public domain. This applies
worldwide.
Author : TedColes
Description : Five hole and eight hole perforated paper tape as used in telegraph and computer applications
4
English: ENIAC (Electronic Numerical Integrator And Computer) in Philadelphia,
Pennsylvania. Glen Beck (background) and Betty Snyder (foreground) program the
ENIAC in building 328 at the Ballistic Research Laboratory (BRL).
https://commons.wikimedia.org/wiki/File:Eniac.jpg
UNIVAC 1
https://www.thocp.net/hardware/univac.htm
5
Second Generation – Transistors
(1956 – 1963)
o Vacuum tubes replaced by transistors
o Very Significant Development.
Smaller, Faster, Cheaper, Less Power
consumption
o Punched card for input and printouts.
o Development of Assembly Language
using Mnemonics
o Languages like ALGOL, FORTRAN,
COBOL were being developed (HLL)
o Instructions and Data were being
stored in Main Memories called
magnetic Cores (1955 – 1975)
6
Link: https://commons.wikimedia.org/wiki/File:KL_CoreMemory.jpg
License : This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
Author : Konstantin Lanzet
Description : Core Memory Module
IBM 1401
https://commons.wikimedia.org/wiki/File:BRL61-IBM_1401.jpg
7
Third Generation – Integrated
Circuits (1964 – 1971)
o Dawn of the Silicon based Chips
o Transistors fabricated and densely
packed on these chips
o Huge gains in speed, reliability
o Advent of Keyboards and Monitors
along with OS for managing Hardware
o End of Punched Cards and Paper Tapes
o With modern OS, multiple applications
could be executed simultaneously
o Cheaper, more compact machines led
to usage in more organizations, like
banks and other financial institutions.
8
Link: https://commons.wikimedia.org/wiki/File:IBM_System360_Model_30.jpg
License : This file is licensed under the Creative Commons Attribution 2.0 Generic license.
Author : Dave Ross
Description : An entry-level IBM System/360 system, on display at the Computer History Museum.
9
Fourth Generation –
Microprocessors (1972 – 1989)
o Revolutionary Intel 4004 Processor
o Housed CPU, RAM, I/O and CU on single
chip
o Transformed Size from a ROOM to a
PALM
o Landmark 1981 IBM PC for Personal
use. 1984 Apple McIntosh
o Microprocessors and ICs got into all
aspects of life. VLSI
o Faster, Affordable, mass market, wider
adoption from business to homes
o Powerful machines helped spawn the
growth of the Internet
o GUI, Laptops, Palmtops etc
10
PDP-11
Link: https://commons.wikimedia.org/wiki/File:Pdp-11-40.jpg
License : This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported
license.
Author : Stefan_Kögl
Description : PDP11/40 as exhibited in Vienna Technical Museum
11
Fifth Generation – Artificial
Intelligence, Parallel Computing,
Networking (1990 till date)
o Ultra Large Scale Integrated
Technologies (ULSI)
o High Capacity Hard disks, Main
memories
o Serious attempts to use Computers to
do tasks human do using AI
o Massively Parallel Computers
Cloud Computing
o Data Centers, Internet in all domains
and aspects of life
o Truly the dawn of the Information age
using Computers
o Challenging applications like Natural
Language Processing (NLP) being
addressed
12
IBM Blue Gene P supercomputer
Link: https://commons.wikimedia.org/wiki/File:IBM_Blue_Gene_P_supercomputer.jpg
License : This file is licensed under the Creative Commons Attribution-Share Alike 2.0 Generic license.
Author : Argonne National Laboratory's Flickr page
Description : The IBM Blue Gene/P supercomputer installation at the Argonne Leadership Angela Yang Computing
Facility located in the Argonne National Laboratory, in Lemont, Illinois, USA.
*****
1
Overview of Computer Networks
o What is a Computer Network?
o Need for a Computer Network
o LAN, WAN
o Common Networking Hardware at
home or labs (Self Discovery).
Million miles high overview of computer
networks
2
What is a Computer Network?
o An interconnection of nodes via means
of digital technology for resource
sharing and provision of services
o Connectivity may be established by
the means of Physical cables, Optical
wires or Wireless technologies.
o They communicate by the means of
established rules called as Protocols
o Nodes may be Computers, Printers,
Scanners, Servers etc
o Example of Resource sharing may be
a high speed printer
3
o Resources are services (information
information or
Physical devices) provided by the
Network Nodes.
o Devices are identified by names and
addresses for unique identification
o Unique identification is required for
locating and communicating to the right
node.
Descr:: An anchor chart (large poster for classroom display) which is based on the key Network theory content
from OCR's GCSE in Computer Science J276. Teaches: Network hardware devices, packet switching, VPNs,
Client Server Networks, Network Topologies, LAN vs WANS and Wifi vs Wired networks
License:: This file is licensed under the Creative Commons Attribution
Attribution-Share
Share Alike 4.0 International license.
Author:
Mrlaulearning
Link: https://commons.wikimedia.org/wiki/File:Computer_Networks_anchor_chart.svg
7
Common Networking Hardware
o A Network interface card (network
interface controller) connects a
computer to a computer network,
usually a LAN.
o Modern computers support an internal
NIC embedded on the motherboard
Link: https://commons.wikimedia.org/wiki/File:Ethernet_NIC_100Mbit_PCI.jpg
Description: 100MBit Ethernet NIC PCI card
Author: afrank99
License: This file is licensed under the Creative Commons Attribution-Share Alike 2.0 Generic license.
8
Conceptual Diagram of a Com
mputer
Network
Link: https://en.wikipedia.org/wiki/File:Sample
https://en.wikipedia.org/wiki/File:Sample-network-diagram.png
Descr: Depicts a sample, hypothetical network diagram.
Author: SilverStartalk
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Attribution-ShareAlike
ShareAlike 3.0 License
9
Network Switch
o Connects other devices together.
o Manage the flow of data across a
network by transmitting only to the
devices addressed.
https://commons.wikimedia.org/wiki/File:Netgear_Gigabit_Switch_5-port.jpg
Author Simon A. Eugster
License: This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
Description: A 5-port gigabit ethernet switch by Netgear. The LED above the red plug indicates an existing link (i.e. it is
connected to some other device), the yellow cable is unconnected.
10
Router
o At home provides Wi-Fi connectivity
and is connected to a modem.
Broadcasts
information
from
the
internet
to
other
devices,
like
computers, phones, and tablets.
o In the networking scheme of things it
forwards data packets from one router
to another router through the networks
based
on
the
address
of
the
destination.
Link: https://commons.wikimedia.org/wiki/File:Netgear-Nighthawk-AC1900-WiFi-Router.jpg
Description: A Netgear Nighthawk WiFi router, model AC1900. This is a wireless router first released in 2013
with a list price of $249. It is a dual band router with a 1GHz dual core
Author Evan-Amos
License: I, the copyright holder of this work, release this work into the public domain. This applies
worldwide.
11
Firewall
o A network security system that
monitors, controls to and from traffic
from the network based on rules of
security established. Acts as barrier
between a trusted network and an untrusted network, like the Internet.
English: Firewall separating zones of trust
Author Luis F. Gonzalez
I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
https://commons.wikimedia.org/wiki/File:Firewall_(networking).png
12
Modem
o Stands for "modulator-demodulator" –
is a hardware device. Transforms Analog
signals coming from networks like
Telephone, Cables etc to Digital Signals
and vice versa.
https://commons.wikimedia.org/wiki/File:BSNL-ADSL_Modem.JPG
Description: Picture of BSNL ADSL Modem
Author: Lijorijo at Malayalam Wikipedia
License: This file is licensed under the Creative Commons Attribution 2.5 Generic license.
13
Proxy Server
o A server application that acts as an intermediary for requests
from clients seeking resources from servers that provides
those resources. A proxy server thus functions on behalf of the
client when requesting service, potentially masking the true
origin of the request to the resource server.
o Instead of connecting di
directly
rectly to a server that can fulfill a
requested resource, the client directs the request to the proxy
server, which evaluates the request and performs the required
network transactions. With benefits such as load balancing,
privacy, or security
security*
* Information Courtesy Wikipedia
https://commons.wikimedia.org/wiki/File:CPT
https://commons.wikimedia.org/wiki/File:CPT-Proxy.svg
Author Milesjpool,
Description: Diagram of a blocked web request, and a successful request via a proxy
License: This file is licensed under
nder the Creative Commons Attribution
Attribution-Share
Share Alike 4.0 International license.
*****
4
Why do we need a Computer Network?
o Share the resources (Physical and
Software) and in communication.
o Users can exchange information through
file sharing.
o Some applications can be submitted to
high-powered machines. Following a
client-server model
o Communicate via email, blogs, chats,
and social media.
o Voice calls using Internet Protocol (IP)
o Education during Covid-19
o Sharing of Hardware devices such as
printers, scanners, secondary memory
i.e. Storage, processor etc
5
Types of Computer Networks
Local Area Networks (LAN)
o Generally a network owned and
operated by a single entity
o Restricted are small office,, lab,
building, school or our university
campus
Link : https://commons.wikimedia.org/wiki/File:Ethernet_LAN.svg
Author :
T.seppelt, derivate work from File:Ethernet.png,
Description : ethernet network
License : This file is licensed under the Creative Commons Attribution
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International license.
6
Wide Area Networks (WAN)
o Across Wide Geographical Area
o Composed on multiple LAN’s
interconnected
o Best example the Internet
Link : https://commons.wikimedia.org/wiki/File:Lanwan.gif
License: This file is licensed under the Creative Commons Attribution-Share Alike 4.0
International license.
Author: Audit3
Description: Wide Area Network
1
Computer Booting Process in
Simple Words
Background
o A computer requires an Operating system
to become usable
o The Operating system to work must be
loaded into the main memory
o Booting involves getting the hardware
activated and….
o Broadly to load and hand over charge of
the Computer to the Operating System
o Very General and broad overview of the
Booting Process is provided. Technical
accuracy has been adjusted for conceptual
clarity.
/* Acknowledgement of the Image Source next slide…
Link : https://commons.wikimedia.org/wiki/File:Power_On_-_texture.jpg
Description:
The power button of an ASUS laptop with surrounding concentric pattern.
Attribution : (required by the license) © User:Colin / Wikimedia Commons / CC BY-SA 4.0
Changes: Image Cropped
*/
2
Step 0
o Switch on the Main Power Supply to
the Computer
o Switch on the PC/Laptop Power Button
o Power is supplied to all components on
the motherboard and other hardware
to allow them to work.
o It is possible that the power supply
may have some problems leading to
incorrect voltage levels, this leads to a
power failure message and the starting
is aborted.
Information: On a Computer Motherboard
there is a special ROM called as the ROM
BIOS (Basic Input Output System). This
ROM called as BIOS is an EPROM (to allow
future upgrades) comes pre-installed with
the Computer
3
Step 1
o CPU (Pre-Configured) goes to a
specific location in the RAM and
executes a Jump to the ROM BIOS
address
o The CPU first loads data from a ROM,
which executes a Power on Self Test
(POST). In this phase a diagnosis is
run to see if all the major hardware
components are working normally.
o Checks keyboard connection, video
cards, speakers, main memory; etc
Data is written and read back from
main memory to see if RAM is
functioning properly.
o For example informs through beeps
any known problems. Generally one
beep to say all is well or two beeps to
indicate some issue.
4
Step 2
o Only on successfully completing the
POST process, Bootstrap loader
executes.
o Its job is to locate and load the
Operating system into the Computer
Boot Strapping: Pick up one self or in
simple words self improvement by one’s
own efforts
1
Course Outcomes
Guaranteed PATH to being a
multimillionaire and a career in a
top notch company
2
o First step into the Wonderful world
of programming
o Master
Programming
Logic
Algorithms and then flowcharts (
MOST IMPORTANT )
o Sound
skills
programming
in
computer
o Be able to write code on your own
o Follow the lecture sequence
o Religiously follow the sessions and
complete suggested assignments
3
/* Images Acknowledgement and Credits from Wikimedia Commons */
Author: Videoplasty.com
Trophy Flat Icon.svg from Wikimedia Commons
License: Creative Commons Attribution-ShareAlike 4.0
Credit line example: "Trophy Flat Icon.svg from Wikimedia Commons by Videoplasty.com, CC-BYSA 4.0"
Descr: Success road sign.
License: This file is licensed under the Creative Commons Attribution-Share Alike 2.0 Generic license.
Author: Keith Ramsey (RambergMediaImages)
Link: https://commons.wikimedia.org/wiki/File:Success_sign.jpg
*****