Lesson 1

Introduction to Computers

&Management

Information System

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Topics to cover

Charecteristics of a Computer

The Binary Story

Computer System Organisation

Memory

Types & classification of Computers

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Charecteristics of a Computer

Speed Process voluminous data at amazing

speed Storage

Important feature of Computing technology is storing the data

Accuracy Accurate always

Versatility Can compute arithmetic, text &

Logical operations too

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Charecteristics of a Computer

Compactness From big Machines to palmtop

Reliability More reliable than the human brain

Repititiveness Performs similar iterative task without

loosing speed or accuracy Diligence

Does not loose concentration or get fatigued

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The Binary Story

BIT BYTE WORD 1 1 BIT 21 20

2 1 = 3 (3 )10 (11)2

Each symbol of 0 or 1 is known as a BIT

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B I T Binary Two-State-Operation A number system using the base of

2 Only 2 numeric symbols - 0 & 1 Conversion of Decimal to Binary &

Binary to decimal

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Conversion

Decimal to Binary 15 = 2 15 - 1 L S D = 2 7 - 1 = 2 3 - 1 = 2 1 - 1 M S D = 1 1 1 1

Binary to Decimal 1 1 1 1 = 23 22 21 20

8 +4 + 2 + 1 = 15

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BYTE

The alphabets or numbers are represented with 8 bits or 16 bits or 32 bits and so on

A group of BITs used to represent an alphabet or a numeral or a character is called a BYTE Ex in an 8 bit machine 1 alphabet or

numeral is represented using 8 BITS Here 1 BYTE = 8 BITS

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WORD

No. of bits needed by a computer memory to store one unit of information is called a WORD.

1 byte = 8 bits 1 kilobyte(KB) = 1024 bytes 1 Megabyte(MB) = 1024 KB 1 Gegabyte (GB) = 1024 MB

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The C P U

Input

Store

Retrive

Output

Storage Device

Auxiliary & Backup Store

Display

Main Memory

Control Unit

Arithmetic & Logic Unit

OutputCentral Processing Unit

( C P U )

Monitor or Display Unit

Key Board

Printer

CD Drive

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Memory ROM

Masked ROM PROM - Programmable Read only

Memory EPROM – Erasable Programmable Read

only Memory UVEPROM - Ultra Violet Erasable

Programmable Read only Memory EEPROM - Electrically Erasable

Programmable Read only Memory

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Main Memory

Main Memory

Control Unit

Arithmetic & Logic Unit

Random Access Memory ( R A M ) for Read & Write

Read Only Memory (R O M )

O/S Appln Prgm

Exec Prgm

BIOS

Supervisory Memory

User memory

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R O M

Control Unit

Arithmetic & Logic Unit

Main Memory

Random Access Memory ( R A M ) for Read & Write

(R O M )

O/S Appln Prgm

Exec Prgm

BIOS

Supervisory Memory

User memory

1. Masked ROM 2. P R O M 3. E P R O M 4. E E P R O M

D A T A

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4 Type of R O M Masked R O M –

A bit pattern is permanently recorded. Specialised Manufacturing Process. Very Expensive

P R O M - Programmable Read Only Memory Can be programmed by User Using PROM Prgm can burn the fuses according to

the bit pattern - “Burning the PROM”

E P R O M – Erasable Programmable Read Only Memory. Info stored is Semi-Permanent. Can be erased by exposing the memory to Ultra

Violet Rays. Can be programmed again Most commonly used

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E E P R O M – Electricity Erasable - Programmable Read Only

Memory Similar to EPROM Info can be altered using electrical

signals Manufacturing process is quite complex Not commonly Used Very Expensive

E A P R O M - Electricity Alterable - Programmable Read Only

Memory

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RAM - Random Access Memory

DRAM - Dynamic Random Access Memory ( uses capacitors)

Disadvantage - discharges slowly ie memory requires refreshing

SRAM - Static Random Access Memory

uses Flip-Flop Registers Faster & Cheaper so widely

used

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Types of Computer

Analog Digital Hybrid

Analog - Solves Problem by operating on contineous Variables.

Digital - performs arithmetic, logical & comparative functions on info in digital form

Combines features of Analog & Digital

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Grid Computer

Super Computer

Mainframes

Mini Computer

Microcomputer

Terminal Embedded Computer

Classification of Computer

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Questions ?

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END Lesson

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