What is a Computer System?

What is it comprise of?How would you define it?

Robots = Computer Systems?

Computer Systems

Hardware Software

Hardware=The physical components (electrical circuits) that make up the computer

Software=The computer programs (sequences of instructions) that tell the computer what to do in response to a command or some event.

Components of a Computer

MAIN MEMORY

PROCESSORINPUT DEVICES

AUXILIARYSTORAGE

OUTPUT DEVICES

For reading data intoMain Memory

For processing the data

For printing, displayingOr out-put of info

For permanent storage of programs and data

The program currently being executed is stored here.(it is divided into storage units called BYTES)

Stored Program ConceptJohn von Neumann(December 28, 1903 – February 8, 1957) Hungarian Mathematician

Think of the Brain (System)

INPUT

PROCESSING

OUTPUTExam Results!

Information for the Exam….

How are computer systems different from a -HUMAN?

Human Beings: Body (Flesh) Soul (Mind, Emotions etc) Spirit (Spiritual)

Computer Systems are the same

Data is INPUT Data is PROCESSED Something is OUTPUT

GIGO (Garbage in…Garbage out..)

Types of Computer

Minicomputers Mainframe Computers Supercomputers

Minicomputers

Multi-user systems 100’s of workstations or terminals

attached to central minicomputer E.g. EPOS (Electronic Point of Sale)

Systems

Mainframe computers

Large Organisations –banks, building societies, airlines, governments

May have 1000’s of terminals –geographically remote locations

Could occupy a whole site 100’s of disk drives & hardware

units Location often kept secret!

(terrorist attacks)

Supercomputers

Largest Category of computer Cost Millions Mostly used by scientific and

industrial research departments NASA –government agencies Weather Centres Stock Exchanges Large Commercial Organisations

PC, Mini, Mainframe or Supercomputer?

PC, Mini, Mainframe or Supercomputer?

World’s Fastest Computer

Roadrunner (Los Alamos National Lab, New Mexico, US)

Jaguar (National Centre for Computational Sciences, Oak ridge, US)

Indian Scenario EKa (Computational Research Laboratories Ltd, Pune ) PARAM (CDAC, Pune)

PC, Mini, Mainframe or Supercomputer?

64-rack Blue Gene complex.

From picasaweb.google.com/.../KyPjMrKhtXMLpvIkZ4Jhtw

The processor

PROCESSES! Faster the processor, better the PC?

What is the equivalent (in humans) to the processor?

How does the Brain process?

-receives an instruction (stimulus) -decodes & produces an appropriate instruction-executes the instruction!

-slap on the cheek –anger/revenge etc logged-anger decoded –instruction to slap back-slap back!(OR TURN THE OTHER CHEEK?)

Processor

Brain of the computer Processes instructionsTHREE STEPS1) Fetches Instructions2) Decodes Instruction3) Executes Instruction

What is a Processor?

Most computers use integrated chips….or integrated circuits for their processors or main memory

A chip is about 1cm square…and can hold MILLIONS of electronic components such as transistors and resistors

CPU of a microcomputer is a microprocessor

Processor and MAIN MEMORY of a PC are held on a single board called a motherboard.

PROCESSORS

Either chips or integrated circuits

Integrated circuits are also found in almost every modern electrical device such as cars, television sets, CD players, cellular phones, etc.

CHIPA computer chip is an electronic circuit (consisting mainly of semiconductor devices, as well as passive components) that has been manufactured in the surface of a thin substrate of semiconductor material.

An electric circuit is made from different electrical components such as transistors, resistors, capacitors and diodes, that are connected to each other in different ways. These components have different behaviors.

The transistor acts like a switch Resistor –resists electricity –so you can control currentCapacitor –controls electricityDiode –also allows control of current and flow

Why Integrated Circuits (transistors)?

Before –there were VACUUM TUBE They were huge –costly –bulky –

easily burned out The first Computer –ENIAC –huge

30 ton monster! *use of 18000 or so vacuum tubes*

Types of Processors

INTEL

32 bit becoming obsolete

64 bit

Multicore Processors

Dual Core – AMD Phenom II X2, Intel Core DuoDual Core – AMD Phenom II X2, Intel Core DuoQuad Core – AMD Phenom II X4, Intel 2010Quad Core – AMD Phenom II X4, Intel 2010Hexa Core – AMD Phenom II X6 , Intel Core i7 Hexa Core – AMD Phenom II X6 , Intel Core i7

Extreme EditionExtreme Edition

MAIN MEMORY

The program currently being executed and the data used by the program is held in MAIN MEMORY

MM is divided into millions of individually addressable storage units called BYTES

One byte can hold one character Or one byte can hold a code representing

something –i.e a part of a picture, or a sound, or a program instruction.

The total number of bytes in MM = The computers MEMORY SIZE.

Computer Memory Sizes

1 KB (KB) =1024 Bytes 1 MB =1024KB 1 GB =1024MB 1Tb =1024GB (about 1

trillion bytes)

Main Memory

Processing power and Main Memory in a computer has increased exponentially in the past year! It has grown at a rate that no one could have predicted.

1980 –Microcomputers with 32K of memory were bought for thousands of homes and schools!

Bill Gates made the famous remark…

“640 K ought to be enough for anybody..” 1981….

Things have changed drastically!

2004 –PC with 512 MB of MM was standard….

Today?

System Unit

RAM and ROM

There are two kinds of Memory RAM –Random Access Memory (MM)(this is used for storing programs that are currently

running and data that is being processed)

ROM –Read Only Memory(its contents are PERMANENTLY etched into the

memory chip at the manufacturing stage. It is used –for example –to load the bootstrap loader (the program that loads as soon as you start the machine)

RAM

Random Access memory Main Memory Stores info about applications that

are open and data VOLATILE – When you switch off the machine, it

disappears!!!

ROM

Read only memory Non-Volatile (does not change) Programs that are necessary for the

computer to run Boot up program etc

Cache Memory

This is a very FAST type of memory that is used to improve the speed of a computer, DOUBLING it ….in some cases.

Acts as an intermediate store between CPU and MM

It works by storing most frequently or recently used instructions so that it is fast to retrieve them again.

Cache is usually between 1KB and 512KB

Disk Storage

Auxiliary storage is also called SECONDARY MEMORY BACKING STORE EXTERNAL MEMORY

The most common secondary memory (auxiliary storage) is DISK!

Hard disk & Floppy Disk

All standalone PC’s come equipped with an in-built hard disk –the capacity of which is also measured in BYTES.

A typical hard disk nowadays is several gigabytes - - is used for storing software including the OPERATING SYSTEM..and other systems software.

Other types of Storage

Flash Memory Cards Sticks Floppy discs Disks

INPUT AND OUTPUT devices

Input devices are the means whereby computers can accept data or instructions

Keyboards, magnetic strip cards, smart cards, magnetic ink character recognition devices,

Output –printer, VDU monitors, speakers, etc

QWERTY Keyboard

Photo: Pre-electric Typewriter

Christopher Latham Sholes (1819-1890)

Embedded Computers and special-purpose computers

Not necessarily all computers are general purpose compuers with a screen, keyboard and disk drive.

Special-purpose or dedicated computers can do all sorts of things from controlling the temperature in a greenhouse to controlling traffic lights or using a cash point

Embedded Computers are used in household goods automobiles and in industry

All Computer Systems

Have the same basic components(INPUT, OUTPUT, PROCESSING,

MEMORY)

Special-purpose computers however usually have the programs etched onto the ROM so that they cannot be altered. (Firmware)

What is this an example of?

Combined Washing machine-Toilet

Household goods…all examples of..?

Devices/Machines with Embedded Computers

Programs are in ROM (cannot be

altered)

All Examples of…!?

Wireless Temperature Control unit for Greenhouse

Special Purpose or Dedicated Computers.

Traffic Light Control Board

All Examples of?

INPUT DEVICES

Odd one out?

Scanner is INPUT, the rest are OUTPUT devices

Monitor

Printers

Scanner

Storage Devices

Edison cylinder phonograph ca. 1899. The Phonograph cylinder is a storage medium. The phonograph may or may not be considered a storage device.

Many different consumer electronic devices can store data.

The Future of Storage?

Genetics!

Storage Medium and Memory

Type MemoryFloppy Disc 1.44 MB

CD-Rom 650MB

Memory Stick (standard) 256 MB

DVD Up to 4 Gig

Hard Disc 40 Gig

Software

• Utility Programs– Small applications that handle important

tasks involved with computer management and maintenance

Software

• Utility Programs– Can be used to:

• Back up important files• Remove unwanted files or programs • Schedule various computer maintenance tasks

Software

• Application Software– Programs created to perform a specific

task or solve a specific need– Fall into one of several categories

• Financial and business• Graphics and multimedia• Educational and reference• Entertainment• Communication• Productivity software

Software

– Productivity software• Word processing• Spreadsheet• Database• Presentation• Communication

Computer Networks

ARPANET – Worlds First Operational Packet Switching Network

First Network

October 29, 1969 at UCLA Mission started with sending “login” Crashed the system after “lo”

Ethernet – Local Area Network

Topologies

Components

RJ 45 Connector

NIC Card

Ethernet Port

Components

Switch

Router

LAN

Ethernet Switching Speed

10 or 100 Mbps (Ethernet) 100 Mbps (Fast Ethernet) 1 Gbps (Gigabit Ethernet) 10 Gbps (10GigE) Ethernet uses Optical Fibre cable,

Twisted Pair cable

Protocol Stack (OSI and TCP/IP)

What is this?

Internet

Internet users in INDIA

Who is this?

Particle Physicist Worked for CERN It happened in 1989 Inventor of WWW

WWW

Tools?

Browsers

Services

Web Search Engines ( Google, Yahoo,

MSN, Bing) Wiki Blogs Social Networks ( Orkut ) Email ( gmail, Yahoo, Hotmail )

Services

Internet Telephony ( Skype ) Internet Radio, TV (wwit.com) Podcasting Chatting (text, audio, video) Youtube

Wireless Technologies

Wireless Technologies

WPAN (Wireless Personal Area Networks) Bluetooth, Zigbee, UWB

WLAN ( Wireless Local Area Networks) WiFi

WMAN ( Wireless Metropolitan Area Networks) WiMax

WRAN ( Wireless Regional Area Networks)

IEEE 802 Standards ProcessIEEE802

802.11WLAN

802.15WPAN

802.16WMAN

802.11g54 Mbit/s

802.11b11 Mbit/s

…

802.15.1Bluetooth

802.15.3High rate

802.11n100 Mbit/s

…

802.16dFixed802.16eMobile

…802.20WMANMobile

802.22WRAN802.22.1Enhanced

Part 74protection

802.22.2Recommended

Practice802.11jRelay

…

802.15.4Zigbee

Wi-Fi Wi-MAX

802.18Regulatory

Matters

Mobile/Cellular Technologies

CDMA GSM

CDMA

Code Division Multiple Access Uses Spread Spectrum technique High Security Operates at 450 MHz, 700 MHz,

800 MHz, 900 MHz, 1700 MHz, 1800 MHz, 1900 MHz, and 2100 MHz

CDMA2000 EV-DO (reliance, tata)

GSM

Global System for Mobile Communications

Operates at 850 MHz, 900 MHz, 1800 MHz, 1900 MHz

Supports Global Roaming GPRS, EDGE (Enhanced Data rate for

GSM Evolution)

Mobile Phone

SIM ( Subscriber Identity Module) for GSM

R-UIM (Re-Useable Identification Module) (for CDMA)

The IMEI (International Mobile Equipment Identity) is a unique 17 or 15 digit code used to identify an individual mobile station to a GSM

*#06#

ATM Networks

Asynchronous Transfer Mode Packet Switching technology for

WAN Cell Switching Gigabit Ethernet will replace ATM

Operating Systems

Windows 7 Ubuntu Linux Google OS

Debian Linux Windows Server 2008 Sun Solaris

Can we have more than one OS in Single System?

Virtualization Hardware, OS, Network, Memory,

Storage or anything VMWare Desktop runs MSWindows,

Linux and MAC OS X

Vmware workstation

Can we do computing with out having OS or Applications installed in our PC?

Cloud Computing

Operating System for Mobiles

Software Licenses

is a legal instrument (by way of contract law) governing the usage or redistribution of software

All software is copyright protected, irrespective of whether it is in the public domain

Proprietary Software software publisher grants a license to use one or more

copies of software, but that ownership of those copies

remains with the software publisher end-user must accept the software license

Free and Open Source licenses

grants recipients rights to modify and redistribute the software “Freedom”

Copyleft GNU Public License (GPL) Free Software Foundation (FSF)

Guarantee & Warranty

Guarantee is a formal assurance that certain conditions will be fulfilled, especially that a product will be of a specified quality

Warranty is a written guarantee promising to repair or replace an article if necessary within a specified period.

’Warranty’ has a time limit, e.g. for 12 months

’Guarantee’ is to a standard of quality and is not time bound... and is non-extendable

Warranty

The ’Manufacturer’s Replacement Warranty’

The ’Manufacturer’s Repair Warranty’

The ’Seller’s Replacement Warranty’

The ’Seller’s Repair Warranty’

Questions?