Introduction to ComputersIntroduction to Computers & &

Management Information Management Information SystemSystem

Lesson 1Lesson 1

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Elements of Computer Systems 2/17

Topics to cover Topics to cover

Charecteristics of a ComputerCharecteristics of a Computer The Binary StoryThe Binary Story Computer System OrganisationComputer System Organisation Memory Memory History & classification of Computers History & classification of Computers

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Elements of Computer Systems 3/17

Charecteristics of a Charecteristics of a ComputerComputer

SpeedSpeed Process voluminous data at amazing Process voluminous data at amazing

speed speed StorageStorage

Important feature of Computing Important feature of Computing technology is storing the data technology is storing the data

AccuracyAccuracy Accurate alwaysAccurate always

VersatilityVersatility Can compute arithmetic, text & Logical Can compute arithmetic, text & Logical

operations too operations too

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Elements of Computer Systems 4/17

Charecteristics of a Charecteristics of a ComputerComputer

CompactnessCompactness From big Machines to palmtopFrom big Machines to palmtop

ReliabilityReliability More reliable than the human brainMore reliable than the human brain

RepititivenessRepititiveness Performs similar iterative task without Performs similar iterative task without

loosing speed or accuracyloosing speed or accuracy DiligenceDiligence

Does not loose concentration or get Does not loose concentration or get fatigued fatigued

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Elements of Computer Systems 5/17

The Binary StoryThe Binary Story

BITBIT BYTEBYTE WORDWORD

1 1 BIT1 1 BIT

2211 2 200

2 1 = 32 1 = 3

(3 )(3 )1010 (11) (11)22

Each symbol of 0 or 1 is known as a Each symbol of 0 or 1 is known as a BIT BIT

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

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

Binary to decimal Binary to decimal

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Elements of Computer Systems 7/17

ConversionConversion

Decimal to BinaryDecimal to Binary 15 = 2 15 - 1 L S D15 = 2 15 - 1 L S D

= 2 7 - 1 = 2 7 - 1

= 2 3 - 1= 2 3 - 1

= 2 1 - 1 M S D = 2 1 - 1 M S D

= 1 1 1 1 = 1 1 1 1 Binary to Decimal Binary to Decimal

1 1 1 1 = 21 1 1 1 = 233 2 22 2 2 211 2 200

8 +4 + 2 + 1 = 158 +4 + 2 + 1 = 15

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Elements of Computer Systems 8/17

BYTEBYTE

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

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

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

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Elements of Computer Systems 9/17

WORDWORD

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

1 byte = 8 bits1 byte = 8 bits

1 kilobyte(KB) = 1024 bytes1 kilobyte(KB) = 1024 bytes

1 Megabyte(MB) = 1024 KB1 Megabyte(MB) = 1024 KB

1 Gegabyte (GB) = 1024 MB 1 Gegabyte (GB) = 1024 MB

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The C P U The C P U

Input

Store

Retrive

Output

Storage Device

Auxiliary & Backup Store

Display

Main Memory

Control Unit

Arithmetic & Logic Unit Output

Central Processing Unit

( C P U )

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MemoryMemory ROM ROM

Masked ROMMasked ROM PROM - Programmable Read only PROM - Programmable Read only

Memory Memory EPROM – Erasable Programmable Read EPROM – Erasable Programmable Read

only Memory only Memory UVEPROM - Ultra Violet Erasable UVEPROM - Ultra Violet Erasable

Programmable Read only Memory Programmable Read only Memory EEPROM - Electrically Erasable EEPROM - Electrically Erasable

Programmable Read only Memory Programmable Read only Memory

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Elements of Computer Systems 12/17

Main MemoryMain 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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Elements of Computer Systems 13/17

R O MR 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

Random Access Memory

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4 Type of R O M4 Type of R O M Masked R O M – Masked R O M –

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

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

bit pattern - “Burning the PROM”bit pattern - “Burning the PROM”

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

Rays.Rays. Can be programmed again Can be programmed again Most commonly usedMost commonly used

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E E P R O M – Electricity Erasable - E E P R O M – Electricity Erasable -

Programmable Read Only MemoryProgrammable Read Only Memory Similar to EPROMSimilar to EPROM Info can be altered using electrical signalsInfo can be altered using electrical signals Manufacturing process is quite complexManufacturing process is quite complex Not commonly UsedNot commonly Used Very ExpensiveVery Expensive

E A P R O M - Electricity Alterable - E A P R O M - Electricity Alterable -

Programmable Read Only MemoryProgrammable Read Only Memory

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RAM - Random Access RAM - Random Access MemoryMemory

DRAM - Dynamic Random Access DRAM - Dynamic Random Access Memory ( uses capacitors)Memory ( uses capacitors)

Disadvantage - discharges slowly ie Disadvantage - discharges slowly ie memory requires refreshingmemory requires refreshing

SRAM - Static Random Access SRAM - Static Random Access MemoryMemory

uses Flip-Flop Registers uses Flip-Flop Registers Faster & Cheaper so widely Faster & Cheaper so widely

used used

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Types of ComputerTypes of Computer

Analog

Digital

Hybrid

Analog - Solves Problem by operating on Analog - Solves Problem by operating on contineous Variables.contineous Variables.

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

Combines features of Analog & DigitalCombines features of Analog & Digital