SAN ACADEMY GROUP OF

SCHOOLS
PALLIKARANAI
CLASS – XI : SKILL SUBJECT
ELECTRONICS & HARDWARE
SUBJECT CODE : 847
 ELECTRONICS & HARDWARE
SUBJECT CODE : 847
MARKS DISTRIBUTION
PART – A : EMPLOYABILITY SKILLS - 10 MARKS
PART – B : SUBJECT SPECIFIC SKILLS - 50 MARKS
PART – C : PRACTICAL - 30 MARKS
PART – D : PROJECT / STUDENT PORTFOLIO - 10 MARKS
 PART-B
UNIT -1: BASIC ELECTRONICS AND COMPUTER
FUNDAMENTALS
Chapter 2: Computer System Fundamentals
Learning Objectives:
 Computer System
 Characteristics and Limitations of a
Computer
 Generations of Computer
 Hardware and Software
 The Input-Process-Output Concept
 Main Components of the Computer
System
 Introduction
♪ Computers are an essential tool of
information technology (IT).
♪ Multi-purpose machines.
♪ Analytical Engine was the first
computer which was invented by
Charles Babbage(Father of Computer)
in 1837. It used punch cards as read-
only memory.
♪ Computers have changed our daily
routine as the entire task performed
by us in our daily routine is
automated.
Analytical Engine
This calculating machine was also
developed by Charles Babbage in 1837.
It was a mechanical computer that used
punch-cards as input. It was capable of
solving any mathematical problem and
storing information as a permanent
memory.
World's first computer
 Computer system
♪ The term "computer" is derived
from the Latin word "computare"
which means to calculate.
♪ The components of a computer
such as machinery that includes
wires, transistors, circuits, hard
disk are called hardware.
Whereas, the programs and data
are called software.
♪ Computer, process the data as
per the given set of instructions.
 Characteristics and Limitations of a Computer
Characteristics:
Computers can execute millions of instructions per
second.
• Calculations are 100% error free • Fast device.
• Calculate large amount of data.
ACCURACY

STORAGE
AUTOMATION
CAPABILITY
More storage capacity.
an automatic machine.
 Store large amount of da
orm a given task based on the given instructions.
 Data such as images, vid
SPEED text, audio, etc.
• Speed in microsecond, nanosecond,
Picosecond.
PROGRAMMABIL
ITY
DILIGENCE
 Free from monotony, tiredne
 Computers can be programmed
and lack of concentration.
to  Work continuously.
execute predefined set of VERSATALITY
 Perform repeated tasks
instructions.
 Very flexible.
 Used to solve the problems related to various fields
 LIMITATIONS
Computers do not have emotions, knowledge,
experience, and feelings.
They can only perform tasks as per the instructions
given by the user and do not take their own
decisions. of Computers:
Generations
 A generation of computers refers to the specific
improvements in computer technology with time.
 In 1946, electronic pathways called circuits were
developed to perform the counting.
 It replaced the gears and other mechanical parts used
for counting in previous computing machines.
 In each new generation, the circuits became smaller and
more advanced than the previous generation circuits.
 The miniaturization helped increase the speed, memory
and power of computers. There are five generations of
computers.
 First Generation
Computers

Some of the popular first generation computers are:

ENIAC ( Electronic Numerical Integrator and
Computer)
EDVAC ( Electronic Discrete Variable Automatic
Computer)
UNIVACI( Universal Automatic Computer)
IBM-701
IBM-650
 Second Generation
Computers

Assembly language and programming

languages like COBOL and FORTRAN,
and Batch processing and
multiprogramming operating systems
were used in these computers.
Third Generation
Computers

The high-level
programming
languages like
FORTRON-II TO IV,
COBOL, PASCAL PL/1,
ALGOL-68 were used in
this generation.
 Fourth Generation
Computers

Some of the popular fourth

generation computers are:

• DEC 10
• STAR 1000
• PDP 11 The programming
• CRAY-1(Super Computer) languages like C, C++,
• CRAY-X-MP(Super DBASE were also used
 Fifth Generation
Computers

Some of the popular fifth generation computers are:

• Desktop
• Laptop
• NoteBook
• UltraBook
• ChromeBook
 Hardware and Software
Hardware:
It consists of mechanical and electronic devices which we can
see and touch
Software:
It consists of programs, operating systems, and the data that
resides in the memory and storage devices.
 Input-Process-Output Concept
A computer is an electronic device that accepts data, processes
data, generates output, and stores data.

Main Components of the Computer System

 A computer has the following three main
components are
(i) input/output unit
(ii) central processing unit

Input and output unit

(iii) memory unit

The input unit accepts data from the user,

converts it into computer understandable form.
Similarly, the output unit provides the output in

Central
a form that is understandable by the user.

 It processing unit
is the main component of the
computer.
 It performs all the processing of input
data and is responsible for activating
and controlling the operations of other
units of the computer.
 Internal architecture of a CPU consists of the
following parts :
(i) arithmetic logic unit (ALU) (ii)
registers
Arithmetic logic unit (ALU):
(iii) control unit (CU) (iv) buses (v)
This unit consists of two subsections namely,
clock
• Arithmetic Section • Logic Section
Arithmetic Section
Function of arithmetic section is to perform arithmetic
operations like addition, subtraction, multiplication, and division.
All complex operations are done by making repetitive use of the
above operations.
Logic Section
Function of logic section is to perform logic operations such as
comparing, selecting, matching, and merging of data.
Registers:
 They are high speed but have low storage in the CPU.
 They are referred to as the CPU’s working memory and
are directly accessed and manipulated by the CPU during
instruction execution.
 They store data, instructions, addresses, and
intermediate results of processing. The data and
instructions are brought in the registers processing.
 Registers:
 They are high speed but have low storage in the CPU.
 They are referred to as the CPU’s working memory and
are directly accessed and manipulated by the CPU during
instruction execution.
 They store data, instructions, addresses, and
intermediate results of processing. The data and
instructions are brought in the registers processing.
Control unit (CU):
 It controls the input, output, and processing activities inside the
computer.
 It directs the computer to carry out stored program instructions by
communicating with the ALU and the registers.
Buses:
 Data is stored as a unit of 8 bits in a register.
 Each bit is transferred from one register to another by means of a
separate wire.
 This group of eight wires which is used as a common way to
transfer
Clock:data between registers is known as a bus.
It is an important component of CPU which measures and
allocates a fixed time slot for processing each and every
micro operation.
 Memory Unit
 It stores all the data and the instructions required for
processing.
 It stores intermediate results of processing.
 It stores the final results of processing before these
results are released to an output device.
 All inputs and outputs are transmitted through the main
FUNCTIONS OF MEMORY UNIT
memory
o Store data & instruction received from input devices.
o Store the intermediate results generated by CPU.
o Store the final result generated by CPU.
Memory is primarily of three
types:
 Cache Memory
 Primary Memory/Main Memory
 Secondary Memory Cache Memory
Cache Memory
 Cache memory is a very high speed semiconductor memory
which can speed up the CPU.
 It acts as a buffer between the CPU and the main memory.
 It consumes less access time as compared to main memory.
 It stores the program that can be executed within a short
period of time.
 It stores data for temporary use.
 Primary Memory / Main
Memory:
 Primary memory holds only those data and instructions on which
the computer is currently working.
 It has a limited capacity and data is lost when power is switched
off.
 The primary storage is volatile. Whenever the power is turned off
the data is lost.
 These memories are not as fast as registers.
 TheTwo kinds of Primary Memory
data and instruction required to be processed resides in the
RAMmain are:
(Random Access Memory)
memory. ROM (Read Only Memory)

RAM means it is possible to randomly select and use any

storage location for storage and retrieval of data.
RAM is also called a read/write memory because data can
both be read from and written onto these units.
When the power is switched off the data stored in the RAM is
lost, so it is called as Volatile Memory.
ROM:
 In this type of memory the data is permanently stored.
 The information can only be read and new data cannot be written
onto this memory.
 However the contents of the ROM are not lost even when the
power is turned off i.e. this memory is non-volatile. Such
memories are also called as field stores, or permanent stores.
 It holds the boot up program called BIOS (Basic Input Output

Memory Management
System) required to boot the computer.

 Data is stored as a machine code.

 Machine code has only two states either 0 or 1.
 Binary digit or bit is the basic unit of memory. A bit is the smallest unit
of representation of data in a computer.
 A group of 8 bits form a byte.
1 Nibble = 4 bits
1 Byte (B) = 8 bits
1 Kilobyte (KB) = 210 = 1024 bytes
1 Megabyte (MB) = 220 = 1024KB
1 Gigabyte (GB) = 230 = 1024 MB = 1024*1024 KB
1 Terabyte (TB) = 240 = 1024 GB = 1024*1024*1024 KB
 Secondary Memory
Used for storing data/information permanently.
Also known as external memory or non-volatile or backup
memory.
CPU directly does not access these memories, instead they are
accessed via input-output routines. Slower than primary
memories.
The contents of secondary memories are first transferred to the
main memory, and then the CPU can access it. For example, disk,
CD-ROM, DVD, etc.
Secondary
Computer maymemory (storage
run without the devices)
secondary memory.
Data
A. Hard is permanently
Disk stored even
Drive (Local Disk) if power
Magnetic is switched
storage device. off.
High storage
capacity and
high data transfer rates.
B. Optical Storage Devices: (CD-R, CD-RW, DVD-R, DVD-RW ,Blue-ray
disk)  uses a low
power laser beam to read from and write data into it.
CD – Compact Disk  uses red laser beams for reading from and
writing data into CDs.
CD-R (Compact disc recordable)  Data can be written once and read
many times .
CD-RW (Compact disc rewritable)  It can be erased and rewritten at
C. Flash Drive(Pen Drive)  Small external storage device.
Faster and durable as compared to other
types of secondary
memory. Portable and rewritable.
Capacity
E. Floppy varies
Disks from 2 GB
F. Memory toG.
Cards 128 GB. Hard D
External
D. Zip Drive (Super disk)
 Classification of
On theComputers
basis of working principle , computers can be
classified into two types:
Computer

General Purpose Computers

Home

Educational Institute

Office

Special Purpose Computers

Analog

Digital

Hybrid
 Analog computers
Deal with analog data which represents the continuously varying
physical quantities, such as current, voltage, or frequency.
Examples are:

Digital computers
A computer that performs calculations and logical operations with
quantities represented as digits, usually in the binary number system.

Hybrid Computer (Analog +

Digital)
A combination of computers those are capable of
inputting and outputting in both digital and analog
signals.
A hybrid computer system setup offers a cost
effective method of performing complex simulations
 Classification of
On theComputers
basis of size, computers can be classified into two
types:
Computer

Super Computers

Mainframe Computers

Mini Computers

Micro Computers

Desktop

Laptop

Mobile

Palmtop
Workstations

Comput Noteboo
ers k
Smartph Tablets( Digital
ones e.g) iPad Dairy
PDA’s  Personal Digital
Assistant
 • Used for complex scientific
application.

Super • Used multiprocessor technology to

perform the calculation very speedy.
• cost of the super computer is

Comp depended on its processing

capabilities &
• Configuration.

uter • Mainly used in weather forecasting,

biomedical research, aircraft design,
remote sensing, and other areas of
science and engineering.
Mainfra •A very powerful computer which capable of
supporting thousands of user simultaneously.

me
•Contains powerful data processing system.
•Capable to run multiple operating systems.
•Mainly used to handle bulk of data & information for

Compute processing.
•Much bigger in size & needs a large rooms with
closely humidity & temperature.

r •Mainframes are very large & expensive computers .

 microprocessor chip as it central
processing unit.
Micro • Microcomputer is known as
personal computer.

Comp
• Designed to use by individual
whether in the form of pc’s,
workstation or notebook

uter computers.
• Small in size and affordable for
general people.
• This has the lowest speed and

Mini storage
•Less capacity.
expensive than mainframe computer.
•Mini computers are Lower mainframe in the terms
of processing capabilities.

Comp
•Capable of supporting 10 to 100 users
simultaneously.
•It uses Multiprocessing.
•This type of computer is generally used for

uter
processing a large volume of data. It is also used
as a server in Local Area Networks (LAN).
 Classification of
On theComputers
basis of Brand, computers can be classified into two
types:

• IBM PC began with the original IBM PC that was

introduced in 1981.
IBM • Other companies began manufacturing similar
computers which were called IBM Compatible.

• Macintosh introduced the first personal computer

Apple / with graphical user interface (GUI) in 1984.
Macintosch • Macs are made by Apple Inc., and use Mac OS X
(an operating system).