2018

COMPUTER
AWARENESS
PART I

BY: WWW.ANUJJINDAL.IN
 PART 1 COMPUTER AWARENESS

COMPUTER

A Computer is a General-purpose machine, commonly consisting of digital circuitry,

that' accepts (inputs), stores, manipulates, and generates (outputs) data as numbers,
text, graphics, voice, video files, or electrical signals, in accordance with instructions
called a program.

Father of the computer - Charles Babbage

Father of the modern computer - Alan Turing

Basic Architecture of Computer: John Von Neumann

First Programmer: Lady Ada Augusta

First Electronic Computer: ENIAC-I(1946) - J.P. Ekart & J.W. Moschley

First computer for the home use introduced - IBM in 1981

MAINS PARTS OF COMPUTER

Hardware- Computer hardware is what you can physically touch includes the
computer case, monitor, keyboard, and mouse. It also includes all the parts inside the
computer case, such as the hard disk drive, motherboard, video card, and many
others.

Input Devices - In computing, an input device is a peripheral (piece of computer

hardware equipment used to provide data and control signals to an information
processing system such as a computer or information appliance. Examples: keyboards,
mice, scanners, digital cameras and joysticks.

Keyboard -A Keyboard is the most fundamental input device for any

computer system. It helps to enter data in computer.

Mouse - A mouse is used to input data by sending a signal to the computer, based on
hovering the, cursor and selecting with the left mouse button. The left mouse acts as
a 'enter' button. The right mouse button can be selected and will often pop up a
window of choices. The scrolling wheel is used to move the view of the screen up or
down. By moving your mouse to a location in a document, on a digital photo or over a
choice of music, you can click the left mouse button to place the cursor.

Trackballs - A trackball is an input device used to enter motion data into computers
or other electronic devices. It serves the same purpose as a mouse, but is designed
with a moveable ball on the top, which can be rolled in any direction. Instead of
moving the, whole device. you simply roll the moveable ball on top of the trackball
unit with your hand to generate motion input.
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Barcode Reader - A barcode reader (or barcode scanner) is an electronic device that
can read and output printed barcodes to a computer. Like a flatbed scanner, it
consists of a light source, a lens and a light sensor translating optical impulses into
electrical ones,

Digital Camera- A camera which produces digital images that can be stored in a
computer and displayed on screen.

Gamepad - A handheld controller for video games.

Joystick - A lever that can be moved in several directions to control the movement of
an image on a computer or similar display screen. It is mainly used in playing gamers.

Microphone- An instrument for converting sound waves into electrical energy

variations which may then be amplified, transmitted, or recorded.

Scanner- A device that scans documents and converts them into digital data.

Webcam- A video camera connected to a computer, allowing its images to be seen

by Internet users.

Optical Character Recognition (OCR) - Is the mechanical or electronic conversion of

images of typed, handwritten or printed text into machine-encoded text.

Digitizer - It converts analog information into digital form.

Optical Mark Reading (OMR) - Optical Mark Readers reads pencil or pen marks made
in pre-defined positions on paper forms as responses to questions or tick list

BASIC STRUCTURE OF CPU

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CPU (Central Processing Unit)

A central processing (CPU) is the electronic circuitry within
a computer that carries out the instructions of a computer program by performing the
basic arithmetic, logical; control and input/output (I/O) operations specified
by the instructions.

• CPU — Heart of the Computer

• CPU Process:
1. Fetch the instruction
2. Interpret the instruction
3. Fetch the data
4. Process the data
5. Write the data

OUTPUT DEVICES
An output device is any device used to send data from one computer to another
device or user. Most computer data output that is meant for humans is in the
form of audio or video. Examples include monitors, projectors,
speakers, headphones and printers.

Monitor- A Monitor is a TV-like display attached to the computer on which the output
can be displayed or viewed. It can either be a monochrome display or
a colour display.
There are two kinds of monitors
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1. CRT (Cathode Ray Tube)- The cathode ray tube(CRT) is a vacuum tube
containing one or more electron guns and a phosphorescent screen used to view
images.

2. Thin-Film-Transistor Liquid- Crystal Display (TFT LCD)- A thin-film-transistor

liquid-crystal display (TFT LCD) is a variant of a liquid-crystal display (LCD) that uses
thin-film transistor technology to improve image qualities such as addressability and
contrast.

Printer- Printer is an output device for printing text or pictures.

1. Impact Printer- An impact printer is a printer that strikes a print head against an
ink Ribbon to mark the paper. Common examples include Dot Matrix and Daisy-wheel
printers.

2. Non-Impact Printers- A non-impact printer prints the characters without using

label. Two common type non-impact printers include inkjet printers, which spray
small drops of ink on to each page and Laser printers, which role ink onto the using a
cylinder.

MEMORY

PRIMARY MEMORY OR MAIN MEMORY

Register: Register is one of a small set of data holding places that are part of the
computer processor. Register may hold on instruction, a storage address, or any kind
of data (such as a bit sequence or individual characters). Some instructions specify
registers as part of the instruction.
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RAM (Random Access Memory) - Random Access Memory (RAM) is a type of data
storage used in computers that is generally located on the motherboard. This type of
memory is volatile and all information that was stored in RAM is lost when the
computer is turned off.

There are two types of Random Access Memory.

1. Dynamic Random Access Memory- Dynamic indicates that the memory must be
constantly refreshed (re-energized) or it will lose its contents.

2. Static memory- A Computer memory that contains fixed information and retains its
programmed state as long as the power is on.
Virtual memory is a feature of an operating system (OS) that allows a computer to
compensate for shortages of physical memory by temporarily transferring pages of
data from Random Access Memory to disk storage.

ROM (Read Only Memory) - Once data has been written onto a ROM chip it cannot be
removed and can only be read. Unlike main memory (RAM), ROM retains its contents
even when the computer is turned off. ROM is referred to as being a nonvolatile.

There are three types of Read Only Memory.

1. PROM- PROM stands for Programmable read only memory. R this form of ROM is
initially blank. The user or manufacturer can write data/program on it by using
special devices. However, once the program or data is written in PROM chip, it cannot
be changed. If there is an error in writing instructions or data in PROM, the error
cannot be erased. PROM chip becomes unusable.

2. EPROM- EPROM stands for erasable Programmable read only memory. This form of
ROM is also initially blank. The user or manufacturer can write program or data on it
by using special devices. Unlike PROM, the data written in EPROM chip can be erased
by using special devices and ultraviolet rays. So program or data written in EPROM
chip can be changed and new data can also be added. When EPROM is in use, its
contents can only be read.

3. EEPROM- EEPROM stands for electrically erasable Programmable read only

memory. This kind of ROM can be written or change with the help of electrical
devices. Show data stored in this type of ROM chip can be easily modified.

CACHE
A cache is a place to store something temporarily in a computing environment. Cache
memory, also called CPU memory, is Random Access Memory (RAM).
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RAM vs. ROM

RAM ROM
FUNCTION Stores the currently active Stores certain fixed routine
programs and their data such as the boot-up routines.
VOLATILITY RAM is volatile. When the ROM is non-volatile. When the
computer is switched off, the computer is switched off, the
contents are lost. contents are not lost.
CHANGEABLE The contents of RAM can be The contents of ROM cannot be
changed or deleted. changed or deleted.

MEMORY UNITS
Storage capacity is expressed in bytes. The data is represented as binary digits (0s and
1s)
Hierarchy- Nibble < bit < byte < KB < GB < GB < TB < PB < XB < ZB< YB
American standard code for information interchange (ASCII) is the standard code the
computer industry created to represent characters (more than 64 characters)

1 4 bit Nibble
2 8 bit 1 byte
3 1024 B 1 KB
4 1024 KB 1 MB
5 1024 MB 1 GB
6 1024 GB 1 TB
7 1024 TB 1 PB
8 1024 PB 1 XB
9 1024 XB 1 ZB
10 1024 ZB 1 YB

SECONDARY MEMORY
Secondary memory is a type of Computer memory that is not directly assessed by the
central Processing Unit (CPU) of a computer and is usually available as non-volatile
memory. One of the most common forms of this memory is the hard drive of a
computer, which is used to store the operating system (OS) and other programs. Other
forms of secondary memory include disk drives for compact discs (CDs) or Digital
versatile discs (DVDs), as well as removable flash memory.

Hard Drive- A rigid non-removable magnetic disk with a large data storage capacity.

Floppy Disk- A floppy disk, also called a diskette or just desk, is a type of disk storage
composed of a disc of thin and flexible Magnetic storage medium, sealed in a
rectangular plastic carrier lined with fabric that removes dust particles. Floppy disks
are read and written by a floppy disk drive (FDD).
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Magnetic Tape- Magnetic tape used in recording sound, pictures, and computer data.

Flash Memory- A kind of memory that retains data in the absence of a power supply.

Optical Disc - An electronic data storage medium that can be written to and read
using low power laser beam.

ü CD-ROM: "read only" (used for distribution of commercial software). Standard

storage capacity is 640 MB.

ü CD-R (or CD-WORM): "write once, read many" times

ü CD-RW: Rewritable multiple Times

ü DVD: Similar to CD, art with significantly large storage capacity (4.7 GB)

ü Write once read many (WORM) describes a data storage device in which
information, once written, cannot be modified.

MOTHERBOARD
A motherboard is the main circuit board inside a computer that connects the different
parts of a computer together. It has sockets for the CPU. RAM and expansion cards
(example discrete graphics cards, sound cards, network cards, storage cards, etc.)
and it also hook up to hard drives, and front panel ports with cables and wires, also
known as mainboard, system board.

DEVELOPMENT OF COMPUTER
Abacus- Abacus is known to be the first mechanical calculating device which was used
to perform addition and subtraction easily and speedily. Abacus is made up of wooden
frame in which rod which is fitted across with round beads sliding on the rod.

Pascal Calculator- In the year 1642, Blaise Pascal a French scientist invented and
adding machine called Pascal's calculator, which represents the position of digit with
the help of gears in it.

Analytical Engine- A scientist from England known to be Charles Babbage invented

such a machine. This device was called analytical engine and it being the first
mechanical computer. It included such feature which is used in today's computer
language. For this great invention of the computer, Sir Charles Babbage is also known
as the father of the computer.
GENERATIONS OF COMPUTER
GENERATION PERIOD MAIN ELECTRONIC MAIN COMPUTERS
COMPONENTS
 PART 1 COMPUTER AWARENESS

I 1940-52 Electronic Valve Vacuum EDSAC, EDVAC, UNIVAC

Tube
II 1952-64 Transistor IBM-700, IBM-1401, IBM-
1620,CDC-1604,CDC-
3600,ATLAS, ICL-1901
III 1964-71 Integrated Circuit IBM-360, IBM-370, NCR-
395, CDC-1700, ICL-2903
IV 1971-Present Largely Integrated Circuit APPLE, DCM
V Present & Optical Fibre
Beyond

CLASSIFICATION OF COMPUTERS

Classification on working system

1. Digital Computer- Digital computer is the most commonly used type of computer
and is used to process information with quantities using digits, usually using the
Binary System. Example- MacBook.

2. Analog Computer- A computer that operates with numbers represented by directly

measurable quantities (as voltages or rotations) - compare digital computer, hybrid
computer.

3. Hybrid Computer- A computer that combines the characteristics of a digital

computer and an analog computer by its capacity to accept Input and provide output
in either digital or analogue form and to process information digitally.

Classification on size
1. Mini Computer- A computer with processing and storage capabilities smaller than
those of a mainframe but larger than those of a microcomputer.

2. Micro Computer- A microcomputer is a complete computer on a smaller scale and

is largely a synonym for the more common term, personal computer or PC, computer
designed for an individual.

3. Mainframe Computer- A mainframe computer is a very large computer capable of

handling and processing very large amounts of data quickly. They are used by large
institutions, government Agencies and large corporations.

4. Super Computer- The fastest type of computer. Supercomputers are very

expensive and are employed for specialized applications that require immense
amount of calculations.

5. Quantum Computer- The development of this type is in final stage. Probably

quantum computers will be more advanced than that of human brain. In quantum
computers Q-Bit will be used in lieu of Binary Bits.
 PART 1 COMPUTER AWARENESS

SUPER COMPUTERS DEVELOPED IN INDIA

NAME MANUFACTURER
FLO SOLVER NAL, Bengaluru
PACE DRDO
PARAM-10000 C-DAC, Pune
CHIPP-16 C-DOT, Bengaluru
MULTIMICRO IIS, Bengaluru
MACH IIT, Bombay

SUPER COMPUTERS DEVELOPED IN THE WORLD

NAME MANUFACTURER
CRAY KIS CRAY K Research Co., USA
Deep Blue IBM Co., USA
Blue Gene IBM Co., USA
COSMOS Cambridge University, UK