Computer Fundamentals 1st Semester Electrical Engineering Fall 2010 Lecture 1: Components of a Computer System

8/4/2019 Computer Fundamentals 1st Semester Electrical Engineering Fall 2010 Lecture 1: Components of a Computer System

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Computer FundamentalsComputer Fundamentals1st Semester

Electrical EngineeringFall 2010

Lecture 1: Components of a Computer System


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Computers for Individual UseComputers for Individual Use

Desktop computers

The most common type of computer Sits on the desk or floor

Performs a variety of tasks

Workstations

Specialized computers Optimized for science or graphics

More powerful than a desktop


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Computers For Individual UseComputers For Individual Use

Notebook computers Small portable computers

Weighs between 3 and 8 pounds About 8 by 11 inches

Typically as powerful as a desktop


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Tablet computers

Newest development in

portable computers

Input is through

a pen

Run specialized

versions of officeproducts



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Handheld computers Very small computers

Personal Digital Assistants (PDA) Note taking or contact management

Data can synchronize with a desktop

Smart phones Hybrid of cell phone and PDA

Web surfing, e-mail access



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Computers for OrganizationsComputers for Organizations

Network servers Centralized computer

All other computers connect Provides access to network resources

Multiple servers are called server farms

Often simply a powerful desktop


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Mainframes Used in large

organizations Handle thousandsof users

Users access

through a terminal



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Minicomputers Called midrange computers

Power between mainframe and desktop Handle hundreds of users

Used in smaller organizations

Users access through a terminal



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Supercomputers The most powerful

computers made Handle large andcomplex calculations

Process trillions of

operations per second Found in researchorganizations



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Computers in SocietyComputers in Society

More impact than any other invention

Changed work and leisure activities Used by all demographic groups

Computers are important because: Provide information to users

Information is critical to our society Managing information is difficult


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Computers at home Many homes have multiple computers

Most homes in Pakistan have Internet Computers are used forBusiness

Entertainment

CommunicationEducation



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Computers in education Computer literacy required at all levels

Computers in small business Makes businesses more profitable

Allows owners to manage

Computers in industry Computers are used to design products

Assembly lines are automated



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Computers in government Necessary to track data for population

Police officersTax calculation and collection

Governments were the first computer users



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Computers in health care Revolutionized health care

New treatments possible Scheduling of patients has improved

Delivery of medicine is safer



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Components of a Computer SystemComponents of a Computer System

Hardware The physical components of a computer

keyboardmousemonitorspeakers

Software The programs that run on a computerWord-processorCalculatorSpread-sheets

Firmware Programs permanently stored in computer ROM


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Each Hardware component of a computerfalls in one of these four categories

Processor Memory

Input/Output

Storage

Buses (Bundles of wires)

Computer HardwareComputer Hardware


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Processor It is the brain of a computer

It reads instructions and executes them one at atime

Multi-core processors can execute multipleinstructions

Components like video cards may have theirown dedicated processor to decrease the burdenor the over-head on the main processor (on themotherboard)



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Processor (continued) The overall performance of a computer is

greatly dependent on the processors speedMemory

It serves as a temporary store-room for theprograms being run. e.g., when a game is

started, it is first loaded into Memory ANALOGY: Books are kept in the shelf, while theone to be studied is placed on the table



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Memory (continued) RAM serves as the Main Memory for the system

The OS reserves a portion of RAM for itself Every subsequent program is given a share inRAM

Devices like video cards have their own

dedicated memory to share burden with RAM



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Cache Moving data from RAM is very much time

consuming because RAM is very slow Hence cache is used; much faster

CPU first looks in the cache, if the requiredinstructions arent present there, it fetches it

from RAM and saves a copy in the cache as wellfor future use



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Cache (continued) Cache is found;

Built into the CPU (L1 cache)External cache on the CPU (L2 cache)

Cache on the motherboard (L3 cache) (in high-endsystems)

Also found on Hard drives and Network cards etc.

Duties L1 cache holds the most recently used instructions

L2 cache holds the possibly upcoming instructions

L3 cache holds a number of possibly requiredinstructions



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Storage Devices Store the data permanently so that it isnt lost

by removing power Examples:Magnetic Storage Devices include Floppy Disksand Hard Disks

Optical Media include CD-ROMs, DVD-ROMs andBlue-Ray ROMs



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Bus A bundle of wires running between different

components of a computer, providing a meansof transferring data and the control signals Two typesInternal (system) bus; resides on the motherboardand connects CPU to the devices that reside on

the motherboardExternal (expansion) bus; connects externaldevices, such as mouse, modem, keyboard,printer etc. to the CPU/motherboard



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Bus (continued) The system bus has two parts;

Data Bus Connects CPU, RAM and other devices on the

motherboard

Number of wires affects the number of bits that can becarried at a time, normally 16-bit, 32-bit and 64-bit

buses are available Like CPU, bus has its own clock-speed, normally

100MHz or 133 MHz. 800 MHz in high computers

Address Bus Connects only the RAM and CPU, used for addressing



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Bus Standards ISA ( Industry Standard Architecture)

16-bit, mid-1980s, used in modems and inputdevices

Local BusInvented for interfacing faster devices

Used in system as well as expansion buses PCI (Peripheral Component Interconnect)A type of Local Bus designed by Intel to integrateaudio, video and graphics



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Bus Standards (continued) AGP (Accelerated Graphics Port)

Based on a special architecture that allows thevideo card to access the RAM directlyNot supported by old PCs

USB (Universal Serial Bus)

Hot swappable (Replace or Add Components to acomputer without shutting it down or restartingit)

Supports up to 127 devices



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IEEE 1394 (Fire Wire) First found only on Macintosh, now present in

IBM compatible PCs as well Used to connect video devices like cameras andvideo cameras, also used for digital TVconnection

PC Card Bus Hot swappable, used mostly with laptops

Used in Wi-Fi cards, network cards & externalModems



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Set of instructions that tell the processorwhat steps to take and in what sequence

Software brings the machine to lifeDiscussed in detail in a later chapter

Computer SoftwareComputer Software


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Firmware is a set of very basicinstructions to guide the computer

through the initial steps on startupBurnt permanently into the systemBIOS (Basic Input Output System) is an

example

FirmwareFirmware


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A BIOS will also have a user interface (or UI forshort). Typically this is a menu system accessed bypressing a certain key on the keyboard when the PC

starts. In the BIOS UI, a user can:configure hardwareset the system clockenable or disable system componentsselect which devices are eligible to be a potential boot

deviceset various password prompts, such as a password

for securing access to the BIOS UI functions itself andpreventing malicious users from booting the systemfrom unauthorized peripheral devices.

FirmwareFirmware


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How Computers Represent DataHow Computers Represent Data

Number systems A manner of counting

Several different number systems existDecimal number system

Used by humans to count

Contains ten distinct digits

Digits combine to make larger numbers


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Binary number system Used by computers to count

Two distinct digits, 0 and 1 0 and 1 combine to make numbers



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Bits and bytes Binary numbers are made of bits

Bit represents a switch A byte is 8 bits

Byte represents one character

Half a byte is called Nibble



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Text codes Converts letters into binary

Standard codes necessary for data transfer ASCIIAmerican English symbols

Extended ASCII

Graphics and other symbols UnicodeAll languages on the planet



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How Computers Process DataHow Computers Process Data

The CPU Central Processing Unit

Brain of the computer Control unitControls resources in computer

Instruction set

Arithmetic logic unitSimple math operationsRegisters


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Machine cycles Steps by CPU to process data

Instruction cycleCPU gets the instruction

Execution cycleCPU performs the instruction

Billions of cycles per second Multitasking allows multiple instructions



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The Machine CycleFetch - get an

instruction from MainMemoryDecode - translate it

into computercommandsExecute - actually

process the commandStore - write the result

to Main Memory



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Memory Stores open programs and data

Small chips on the motherboard More memory makes a computer faster



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Nonvolatile memory Holds data when power is off

Read Only Memory (ROM) Basic Input Output System (BIOS)

Power On Self Test (POST)



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Flash memory Data is stored using physical switches

Special form of nonvolatile memory Camera cards, USB key chains



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Volatile memory Requires power to hold data

Random Access Memory (RAM) Data in RAM has an address

CPU reads data using the address

CPU can read any address



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Components Affecting SpeedComponents Affecting Speed


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Affecting Processing SpeedAffecting Processing Speed

Registers Number of bits processor can handle

Word size(size of the register) Larger indicates more powerful computer

Increase by purchasing new CPU


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Virtual RAM Computer is out of actual RAM

File that emulates RAM Computer swaps data to virtual RAMLeast recently used data is moved



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The computers internal clock Quartz crystal

Every tick causes a cycle Speeds measured in Hertz (Hz)Modern machines use Giga Hertz (GHz)



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The bus Electronic pathway between components

Expansion bus connects to peripherals System bus connects CPU and RAM

Bus width is measured in bits

Speed is tied to the clock



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Peripheral control interface (PCI) Connects modems and sound cards

Found in most modern computers



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Accelerated Graphics Port (AGP) Connects video card to motherboard

Extremely fast bus Found in all modern computers



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Universal Serial Bus (USB) Connects external devices

Hot swappable Allows up to 127 devices

Cameras, printers, and scanners



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Cache memory Very fast memory

Holds common or recently used data Speeds up computer processing

Most computers have several caches

L1 holds recently used data

L2 holds upcoming data L3 holds possible upcoming data



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Architecture Determines

Location of CPU partsBit size

Number of registers

Main difference between CPUs

About the ProcessorAbout the Processor


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Intel Leading manufacturer of

processors

Intel 4004 was worlds firstmicroprocessor IBM PC powered by Intel

8086 Current processorsCentrino

ItaniumDual Core, Core 2 Duo, Quad

CoreCore i3, Core i5, Core i7,

Core i7 ExtremeXeon

Micro Computer ProcessorsMicro Computer Processors


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Advanced Micro Devices(AMD)

Main competitor to Intel Originally produced budgetproducts

Current productsoutperform Intel

Current processorsSempronAthlon FX 64Athlon XP



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Freescale A subsidiary of Motorola

Co-developed the Apple G4 PowerPC Currently focuses on the Linux market



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IBM Historically manufactured mainframes

Partnered with Apple to develop G5First consumer 64 bit chip



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Speed of processorSize of cache

Number of registersBit size

Basis of Comparing ProcessorsBasis of Comparing Processors


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RISC processors Reduced Instruction Set Computing

Smaller instruction sets May process data faster

PowerPC and G5

Advanced Processor TopicsAdvanced Processor Topics


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Parallel Processing Multiple processors in a system

Symmetric Multiple ProcessingNumber of processors is a power of 2

Massively Parallel ProcessingThousands of processors

Mainframes and super computers

Advanced Processor TopicsAdvanced Processor Topics


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Standard computer ports Keyboard and mouse ports

USB ports Parallel

Network

Modem

Audio Serial

Video

Extending Processing PowerExtending Processing Power


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Standard Computer PortsStandard Computer Ports


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Serial and parallel ports Connect to printers or modems

Parallel ports move bits simultaneouslyMade of 8 32 wiresInternal busses are parallel

Serial ports move one bitLower data flow than parallel

Requires control wiresUART (Universal asynchronousreceiver/transmitter) converts from serial toparallel



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Serial CommunicationSerial Communication


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Parallel CommunicationParallel Communication


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SCSI Small Computer System Interface

Supports dozens of devices Fast hard drives and CD-ROMs



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FireWire IEEE 1384

Cameras and video equipment Hot swappable

Port is very expensive



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Expansion slots and boards Allows users to configure the machine

Slots allow the addition of new devices Devices are stored on cards

Computer must be off before inserting



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Plug and play New hardware detected automatically

Prompts to install drivers Non-technical users can install devices



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MonitorsMonitors

Most common output deviceConnects to the video card

Categorized by color output MonochromeOne color with black background

Grayscale

Varying degrees of gray ColorDisplay 4 to 16 million colors


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CRT drawbacks Very large

Very heavy Use a lot of electricity

MonitorsMonitors


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Liquid Crystal Display (LCD) Commonly found on laptops

Desktop versions exist Solve the problems of CRT

Fluorescent lights provide illumination

MonitorsMonitors


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Drawbacks to LCD More expensive than CRT

Must sit directly in front of screen Can be more fragile than CRT

MonitorsMonitors


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Refresh rate Number of time the screen is redrawn

Modern equipment sets this automatically Improper settings can cause eyestrain

MonitorsMonitors


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Device between the CPU and monitorBetter cards result in better output

Removes burden of drawing from CPUHave their own processor and RAMModern cards have up to 5 GB RAMCapable of rendering 3D images

Video CardsVideo Cards


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Replaced overhead and slide projectorsProject image onto wall or screen

LCD projectors Most common type of projector

Small LCD screen

Very bright light

Require a darkened room

Data ProjectorsData Projectors


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Sound card Device between the CPU and speakers

Converts digital sounds to analog Can be connected to several devices

Sound SystemSound System


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Headphones and headsets Replacement for speakers and microphones

Offer privacy Does not annoy other people

Outside noise is not a factor

Headsets have speakers and a microphone

Sound SystemSound System


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Describing Storage DevicesDescribing Storage Devices

Purpose of storage device is to store datawhen computer is off

Two processes Writing data

Reading data


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Storage terms Media is the material storing data

Storage devices manage the media Magnetic devices use a magnet

Optical devices use lasers

Solid-state devices have physical switches

Describing Storage DevicesDescribing Storage Devices


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Data storage and retrieval Media is covered with iron oxide

Read/write head is a magnet Magnet writes charges on the mediaPositive charge is a 1

Negative charge is a 0

Magnet reads charges Drive converts charges into binary

Magnetic Storage DevicesMagnetic Storage Devices


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Data organization Disks must be formatted before use

Format draws tracks on the disk Tracks is divided into sectorsAmount of data a drive can read



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Finding data on disk Each track and sector is labeled

Some are reserved Listing of where files are storedFile Allocation Table (FAT)

FAT32

NTFS

Data is organized in clustersSize of data the OS handles


d d k


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Hard disks Primary storage device in a computer

2 or more aluminum platters Each platter has 2 sides

Spin between 5,400 to 15,000 RPM

Data found in 9.5 ms or less

Drive capacity greater than 40 GB



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R bl hi h it di k


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Removable high capacity disks Speed of hard disk

Portability of floppy disk Several variants have emerged

High capacity floppy diskStores up to 750 MB of data

Hot swappable hard disksProvide GB of dataConnect via USB


CD ROM


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CD-ROM Most software ships on a CD

Read using a laserLands, binary 1, reflect data

Pits scatter data

Written from the inside out

CD speed is based on the originalOriginal CD read 150 KbpsA 10 X will read 1,500 Kbps

Standard CD holds 650 MB

Optical Storage DevicesOptical Storage Devices

DVD ROM


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DVD-ROM Digital Video Disk

Use both sides of the disk Capacities can reach 18 GB

DVD players can read CDs


CD R d bl (CD R)


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CD Recordable (CD-R) Create a data or audio CD

Data cannot be changed Can continue adding until full


CD R it bl (CD RW)


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CD Rewritable (CD-RW) Create a reusable CD

Cannot be read in all CD players Can reuse about 100 times


DVD R d bl


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DVD Recordable Several different formats exist

None are standardized Allows home users to create DVDs

Cannot be read in all players


Data is sto ed ph sicall


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Data is stored physicallyNo magnets or laser

Very fast

Solid State DevicesSolid State Devices

Flash memory


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Flash memory Found in cameras and USB drives

Combination of RAM and ROM Long term updateable storage


Smart cards


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Smart cards Credit cards with a chip

Chip stores data Eventually may be used for cash

Hotels use for electronic keys


Solid state disks


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Solid-state disks Large amount of Synchronous Dynamic RAM

(SDRAM) (SDRAM has a synchronous interface,meaning that it waits for a clock signal beforeresponding to control inputs and is thereforesynchronized with the computer's system bus)

Extremely fast

Volatile storage

Require battery backups

Most have hard disks copying data



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Thank You

Documents

Computer Fundamentals 1st Semester Electrical Engineering Fall 2010 Lecture 1: Components of a Computer System