Introduction to computers

FY - BAF
BALBHARTI’S
M. J. PANCHOLIA COLLEGE OF COMMERCE

INTRODUCTION TO COMPUTERS
 What is a Computer?
 Advantages/Features of Computer
 Definition of Computer
 History of Computer
 Generations of Computers
 Types of Computer
 Hardware & Software
 Parts of Computer (Block Diagram)
 Storage (I/O) Devices
 Software – System Software & Application Software
 Operating Software

What is a Computer?

The computer is one of the greatest
inventions in the history of
humankind. Computers have
applications in all fields of
knowledge and therefore touch all
aspect of our life whatever may be
our field of activity.

The computer can be defined as a
machine that can do calculations,
comparisons, reading and writing on
a given set of data at a very high
speed, logically and intelligently in a
desired manner.

Advantages / Features of Computers

Speed – A computer performs operations with
great speed.
Accuracy – The computer gives accurate
results according to the instruction provided.
Storage – The storage capacity of the
computer is very large
Versatility – Computers are used in vide areas
of human activities.
Automatic – The computer performs all the
instructions provided to it automatically.
Diligence – After long hours of work human
being gets tired but a computer never gets tired.

Definition of a Computer

A computer is an electronic
device, which can perform
arithmetic and logical operations
with a high speed as per
instructions given.

History of Computer

 1642 – Pascal built Mechanical
Calculating Machine
 mechanical gears, hand-crank, dials and
knobs
 other similar machines followed

 1805 – First Programmable device,
Jacquard Loom
 wove tapestries with elaborate,
programmable patterns
 pattern represented by metal punch-
cards, fed into loom
 could mass-produce tapestries,
reprogram with new cards

History of Computer

 Mid 1800's – Babbage designed
"analytical engine"
 expanded upon mechanical calculators, but
programmable via punch-cards
 described general layout of modern
computers
 never functional, beyond technology of the
day

 1890 – Hollerith invented tabulating
machine
 used for 1890 U.S. Census
 stored data on punch-cards, could sort and
tabulate using electrical pins
 finished census in 6 weeks (vs. 7 years)
 Hollerith's company would become IBM

History of Computer

 1930's – several engineers
independently built "computers" using
electromagnetic relays
 physical switch, open/close via electrical
current
 Zuse (Nazi Germany) – destroyed in
WWII
 Atanasoff (Iowa State) – built with grad
student
 Stibitz (Bell Labs) – followed design of
Babbage

Generations of Computers

Generation 1: Vacuum Tubes (1945-1954)
 mid 1940's – vacuum tubes replaced relays
 glass tube w/ partial vacuum to speed electron
flow
 faster than relays since no moving parts
 invented by de Forest in 1906

 1940's – hybrid computers using vacuum tubes and
relays were built
COLOSSUS (1943)
 built by British govt.
(Alan Turing)
 used to decode
Nazi
communications
ENIAC (1946)
 built by Eckert &
Mauchly at UPenn
 18,000 vacuum
tubes, 1,500 relays
 weighed 30 tons,
consumed 140
kwatts


Generation 2: Transistors (1954-1963)
 mid 1950's – transistors began to replace tubes
 piece of silicon whose conductivity can be turned on
and off using an electric current
 smaller, faster, more reliable, cheaper to mass
produce
 invented by Bardeen, Brattain, & Shockley in 1948
(won 1956 Nobel Prize in physics)

 computers became commercial as cost dropped high-
level languages were designed to make programming
more natural

 FORTRAN (1957, Backus at IBM)
 LISP (1959, McCarthy at MIT)
 BASIC (1959, Kemeny at Dartmouth)
 COBOL (1960, Murray-Hopper at DOD)

the computer industry grew as businesses could
buy
Eckert-Mauchly (1951), DEC (1957)
IBM became market force in 1960's


Generation 3: Integrated Circuits (1963-1973)
 integrated circuit (IC)
 as transistor size decreased, could package many
transistors with circuitry on silicon chip
 mass production further reduced prices

1971 – Intel marketed first microprocessor, a chip w/ all
the circuitry for a calculator

 1960's saw the rise of Operating Systems
 an operating system is a collection of programs
that manage peripheral devices and other
resources

 allowed for time-sharing, where multiple users
share a computer by swapping jobs in and out

 as computers became affordable to small
businesses, specialized programming languages
were developed Pascal (1971, Wirth) C (1972,
Ritche)


Generation 4: VLSI (1973-1985)
 Very Large Scale Integration (VLSI)
 by mid 1970's, could fit hundreds of thousands of transistors
w/ circuitry on a chip
 could mass produce powerful microprocessors and other
useful IC's
 computers finally affordable to individuals

 Late 1970's saw rise of personal computing
 Gates & Allen founded Microsoft in 1975 Gates wrote BASIC
compiler for personal computer would grow into software giant,
Gates richest in world
http://www.webho.com/WealthClock

 Wozniak and Jobs founded Apple in 1977 went from garage to
$120 million in sales by 1980

 IBM introduced PC in 1980 Apple countered with Macintosh in
1984


Generation 5: Parallelism & Networking (1985-
????)

In this generation the computers are supposed to use
Artificial Intelligence.

Japan initiated the fifth generation computer project it
was also known as knowledge processing system. It
used a very large scale parallel processing
technologies and incorporated Artificial Intelligence.

Types of Computer

Computers can be classifies as
follows:

Analog Computers: are used for
processing data that vary continuously
such as speed, humidity etc. in such
computers data is given in continuous
form. These computers are not capable
of taking decisions but still are used in
scientific and industrial establishments.

Types of Computer

Digital Computers: Digital computers perform
calculations by counting and are used for
manipulating data with great accuracy. Digital
computers are further classified into:
a) General Purpose – computers are able to
handle many complicated problems by
using programs which are specially
prepared for solving complicated problems
b) Special Purpose – computers are found in
various consumer appliances, these are
different from the computers used by
business organization e.g. computers to
identify mobile problems.

Types of Computer

Hybrid Computer: It is a combination of
Analog and Digital computers. Hybrid computer
are used where continuous and digital
processing is required e.g. to monitor weather
the analog devices may measure the humidity,
temperature etc. the numbers are further
converted into numbers and supplied to digital
component of the system.

Types of Computer

Based on the other features of the computer
such as speed, memory, processing power and
cost computers are classified as follows:
a) Micro Computer (Personal Computer)
b) Desktops
c) Workstations
d) Multimedia
e) Laptops
f) Palmtops
g) Servers
h) Mini Computers
i) Mainframe Computers
j) Super Computers

Hardware & Software

i) Hardware : The hardware consist
of the physical parts of the
computer which can be touched,
seen and felt.
ii) Software: The full set of
instructions and procedures to be
used on the computer is called
software. Software’s can be
classified into:
i) System Software (Operating System)
ii) Application Software

Parts of Computer (Block Diagram)

ALU
Arthematic & Logical Unit

INPUT OUTPUT
CU
Control Unit

MU
Memory Unit
RAM & ROM

Input Devices

 You use an input device, such as a keyboard
or a mouse, to input data and issue commands
 Keyboard
 Mouse
 Game Controller (Joystick)
 Bar Code Reader
 Scanner
 Trackball
 Touch Screen
 Optical Mark Reader (OMR)
 Magnetic Ink Character Recognition (MICR)
 Pen Input
 POS Terminals (Point of Sales
 Digital Camera
 OCR (Optical Character Recognition)
 Microphone

CPU – Central Processing Unit

Data which is entered in the computer is processed in a component
of the system unit called Microprocessor.

The CPU consist of ALU (Arthematic & Logical Section which is
used for computations, CU (Control Unit for monitoring the sequence
of instructions or programs and controlling the other devices
connected to the computer.

The CPU also consist of MU (Memory Unit) which is used to store
data as well as the results given by the computer. The memory unit
is classified into two types:

RAM (Random Access Memory)
Volatile Memory
Data is lost when the lost is switched off.

ROM (Read Only Memory)
Permanent Memory
BIOS (Basic Input Output System)
CMOS (Complementary Metal Oxide Semiconductor)

Output Devices

 Output devices show you the results of processing data
 VDU (Visual Display Unit) or CRT (Cathode Ray
Tube) or Monitor
 LCD
 Sound System
 Printer
 Impact Printers

 Dot Matrix

 Non-Impact Printers

 Laser

 Inkjet / Bubble Jet

 Computer Output Microfilm(Com) Devices

 Plotters

 LCD Projectors
 Communication Device
 Modems

 ISDN

 Broadband Services (Cable Modems)

Data Representation

Computer understands only one language i.e. 8 Bits = 1 Byte
machine language. It is made up of Binary
Digits (0 & 1). 1024 Bytes = 1 KB

1024 KB = 1 MB
The computer stores data in form of Binary
Digits, each digit is known as Bit. Each 1024 MB = 1 GB
character stored in computer is a combination
of 8 Bits (see the table below for example) 1024 GB = 1 TB

ASCII
American Standard Code for
Information Interchange

Storage Devices

The device on which is stored permanently,
which can be used as future reference.
Storage devices are Input / Output devices.
The devices are:
Magnetic Tapes
Magnetic Disk
Floppy Disk
Hard Disk
Optical Storage device
CD
DVD (Digital Versatile Disk)
Flash Memory
Memory Card

Definition of Software

 Instructions and associated
data, stored in electronic format,
that direct the computer to
accomplish a task.

Software

SOFTWARE

Classification of Software

System Application

Hardware cannot work without a Software. System
software is used by the computer to interact with
hardware. Application Software (e.g. MS-Office) cannot
be executed without the installation of system software.
An operating system is system software.

INTRODUCTION TO COMPUTERS Components of OS
System Software File Manager
Stores information on
various secondary
 An Operating System (OS) is the storage devices e.g.
FDD, HDD…. etc
master controller within a computer. Process Manager
EX: Windows, MacOS, DOS (Disk To share several
programs / processes
Operating System), UNIX, Linux to run at the same
time the operating
 An operating system interacts with: system has to share
 All hardware installed in or connected to out microprocessor
time.
a computer system. Device Manager
 All software installed or running from a The device manager
handles
storage device on a computer system. communication
between the
peripherals and the
microprocessor.
Memory Manager
Various programs are
allocated memory in
such a manner that
no clash occurs.

System Software

 Types of Operating System
 CUI (Character User Interface)
Based Operating System
 GUI (Graphics User Interface)
Based Operating System
 Single Task Operating System
 Multitasking Operating System
 Single User Operating System
 Multi User Operating System

System Software - OS
 DOS (Disk Operating System)
 Developed by IBM
 Windows 95/98/XP/VISTA
 GUI
 Windows NT
 Multiuser
 Multitasking
 Networking
 Available in different languages
 Windows 2000
 Windows NT 5.0 – Windows 2000
 Provided more Security
 Available in different local languages.
 UNIX
 Developed by Bell Labs in 1969 – Dennis Ritchie &
Ken Thompson rewrote in C language
 CUI
 UNIX interface is called as Shell

System Software - OS

 LINUX
 Alternate to UNIX
 GUI
 Created by Linus Torvalds – University of Helsinki –
1991.
 Vendors are Red Hat, Caldera Systems, Mandarake …
etc.
 SOLARIS
 Sun Micro Systems deleoped in 1991
 Features of UNIX
 LINUX & Java are also Compatible
 MAC Operating System
 Introduced in 1983 by Apple
 GUI
 Used in Creative Works

Application Software

 Accomplishes specific tasks for users. Application
Software is further
 Enables a computer to become a Classified into:
multi-purpose machine.
1) Propriety

 Produce  Create flow charts 2) Off the Shelf
worksheets and and graphic
reports. organizers.
 Automate record  Communicate
keeping like worldwide.
attendance and
grades.

Personal Operating Software

 Word Processor
 Spreadsheet

 Presentation

 Financial Management

 ERP (Enterprise Resource Planning)

 Raw Material Planning
 Checking Stock & Inventory
 Production & Planning
 Finished Goods Planning
 Sales
 Delivery

Introduction to computers

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Introduction to computers