Fundamental of computers by Neeraj Bhandari ( Surkhet.Nepal )

Fundamentals of Computer Applications

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Assistant Professor

CSE

SHARDA University

Defining Computers

Defining Computers 3

The Computer Defined Electronic device Converts data into information Modern computers are digital

Two digits combine to make data (0, 1)

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The Computer Defined Older computers were analog

A range of values made data

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The Computer Defined Older computers were analog

A more manageable type -- the old-fashioned slide rule

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Basic Organization of ComputerShaveta


CPU It is a core component of the computer. It executes

user’s instructions and processes calculations. Like the chief commander of the army, the CPU

controls and coordinates various devices in the computer system.

Without the CPU, the devices cannot work together and so the computer cannot function.

It is often a etched on a chip and is usually called a microprocessor.

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Basic units of CPUIt has basically to main units CU(Control Unit) ALU(Arithmetic and Logic Unit)

Control unit

Control unit

Arithmetic and logic

unit

Arithmetic and logic

unitSome

registersSome

registers

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Control Unit

The control unit executes the instructions, sends control signals to and receive control signals from peripheral devices.

The control unit executes the instructions, sends control signals to and receive control signals from peripheral devices.

In other words, it controls the whole computer, and directs the entire system to carry out instructions.

In other words, it controls the whole computer, and directs the entire system to carry out instructions.

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Arithmetic and Logic Unit



Arithmetic unitArithmetic unit

Logic unitLogic unit

handles arithmetic calculations

performs logical calculations and makes judgement like “if A > B is true”.

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Registers When the control unit and the arithmetic and logic

unit operate, they store the information and instruction temporarily in registers.

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Program Executions

The diagram shows how the CPU executes an instruction:

The diagram shows how the CPU executes an instruction:

Main memory

Fetch

Arithmetic and logic unit

Control unit

ExecuteDecode

This is called machine cycle.

This is called machine cycle.

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Before a computer executes instructions, they are first placed in the main memory.

Before a computer executes instructions, they are first placed in the main memory.


Fetching

Fetching

Program Executions

The control unit gets the next program instruction from the main memory.

The control unit gets the next program instruction from the main memory.

Decoding

Decoding

The control unit decodes what the instruction means.

The control unit decodes what the instruction means.

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Executing

Executing

Program Executions

The ALU executes arithmetic and logical instructions. It means that the ALU controls and performs the actual operation on the data.

The ALU executes arithmetic and logical instructions. It means that the ALU controls and performs the actual operation on the data.

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Classification of Computers

Defining Computers

Computers for Individual Use

Computers can

be shared by

multiple users

but can be used

by only one

person at a time.

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Defining Computers

Computers for Individual Use Although PCs are used by individuals,

they also can be connected together to create networks.

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Defining Computers

Computers for Individual Use Desktop computers

The most common type of computerSits on the desk or floorPerforms a variety of tasks

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Defining Computers

Computers for Individual Use Desktop computers

Different design types

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Defining Computers

Computers for Individual Use Workstations

Specialized computersOptimized for science or graphicsMore powerful than a desktop

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Defining Computers

Computers for Individual Use Notebook computers

Small portable computersWeighs between 3 and 8 pounds

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Defining Computers

Computers for Individual Use Notebook computers

About 8 ½ by 11 inchesTypically as powerful as a desktop

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Tablet computersNewest

development in portable computers

Input is through a pen

Run specialized versions of office products

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Defining Computers

Computers for Individual Use Handheld computers, palm computer

Very small computersPersonal Digital Assistants (PDA)Note taking or contact managementData can synchronize with a desktop

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Defining Computers


Smart phonesHybrid of cell

phone and PDA

Web surfing, E-mail access

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Defining Computers

Computers for Organizations Network servers

Centralized computerAll other computers connect

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Defining Computers


Flexibility to different kinds of tasks

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Computers for OrganizationsComputers for Organizations

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Defining Computers


Users use the Internet as a means of connecting even if away from the offices.

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Computers for Organizations

MainframesUsed in large organizationsHandle thousands of usersUsers access through a terminal

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Defining Computers

Computers for Organizations Mainframes

Large and powerful systems

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Defining Computers

Computers for Organizations Minicomputers

Called midrange computersPower between mainframe and desktopHandle hundreds of usersUsed in smaller organizationsUsers access through a terminal

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Computers for Organizations

SupercomputersThe most powerful

computers madeHandle large and

complex calculations

Process trillions of operations per second

Found in research organizations

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Defining Computers

Computers in Society More impact than any other invention

Changed work and leisure activitiesUsed by all demographic groups

Computers are important because:Provide information to usersInformation is critical to our societyManaging information is difficult

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Defining Computers

Computers in Society Impact of computers

Like the Impact of automobile

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Defining Computers

Computers in Society

The benefits of using computersAs varied as users

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Defining Computers

Computers in Society Computers at home

Many homes have multiple computersComputers are used for Communication

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Defining Computers

Computers in Society Computers at home

Computers are used forBusinessEntertainmentSchoolworkFinances

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Defining Computers

Computers in Society Computers in education

Computer literacy required at all levels

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Defining Computers

Computers in Society Computers in small business

Makes businesses more profitableAllows owners to manage

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Defining Computers

Computers in Society Computers in

industryComputers are used to design productsAssembly lines are automated

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Defining Computers

Computers in Society Computers in government

Necessary to track data for populationPolice officersTax calculation and collection

Governments were the first computer users

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Defining Computers

Computers in Society Computers in health care

Revolutionized health careNew treatments possibleScheduling of patients has improvedDelivery of medicine is safer

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Memory Memory refers to the physical devices used to store programs

(sequences of instructions) or data (e.g. program state information) on a temporary or permanent basis for use in a computer or other digital electronic device.

Primary memory is used for the information in physical systems which are fast (i.e. RAM), as a distinction from Secondary memory, which are physical devices for program and data storage which are slow to access but offer higher memory capacity. Primary memory stored on secondary memory is called "virtual memory".

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The term "storage" is often (but not always) used in separate computers of traditional secondary memory such as tape, magnetic disks and optical discs (CD-ROM and DVD-ROM). The term "memory" is often (but not always) associated with addressable semiconductor memory, i.e. integrated circuits consisting of silicon-based transistors, used for example as primary memory but also other purposes in computers and other digital electronic devices.

There are two main types of semiconductor memory: volatile and non-volatile. Examples of non-volatile memory are flash memory (sometimes used as secondary, sometimes primary computer memory) and ROM/PROM/EPROM/EEPROM memory (used for firmware such as boot programs). Examples of volatile memory are primary memory (typically dynamic RAM, DRAM), and fast CPU cache memory (typically static RAM, SRAM, which is fast but energy-consuming and offer lower memory capacity per area unit than DRAM) .

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Classification of MemoryMemory

Volatile Non-Volatile

computer memory that requires power to maintain the stored information.

computer memory that can retain the stored information even when not powered.

•RAM•DRAM (e.g., DDR SDRAM)•SRAM•Cache

•ROM•PROM•EPROM•EEPROM•Flash memory

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Full Form Type FunctionRAM Read and Write

MemoryVolatile RAM is a form of data storage that can be

accessed randomly at any time, in any order and from any physical location.

DRAM Dynamic RAM Volatile that stores each bit of data in a separate capacitor within an integrated circuit.

SRAM Static RAM Volatile Each bit in an SRAM is stored on four transistors (M1, M2, M3, M4) that form two cross-coupled inverters

CACHE Volatile Cache is a kind of RAM which a computer system can access more responsively than it can in regular RAM.

ROM Read only Memory Non-Volatile Read-only memory or ROM is also a form of data storage that can not be easily altered or reprogrammed.

PROM Programmable read-only memory

Non-Volatile is a form of digital memory where the setting of each bit is locked by a fuse or antifuse.

EPROM Erasable programmable rea

d only memory

Non-Volatile is a type of memory chip that retains its data when its power supply is switched off

FLASH Non-Volatile which is intended to contribute to portable storage and a convenient transfer of data from one computer to another.

Fundamental of computers by Neeraj Bhandari ( Surkhet.Nepal )

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Transcript of Fundamental of computers by Neeraj Bhandari ( Surkhet.Nepal )