basic of computer system

8/7/2019 Basic of Computer System

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Technical foundationTechnical foundation

of system.of system.Computer TechnologyComputer Technology


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Definition of a ComputerDefinition of a Computer

A computer is aA computer is a universal Information manipulatoruniversal Information manipulator..

A computer as anA computer as an electronic machine capable ofelectronic machine capable of

solving problems by processing or manipulatingsolving problems by processing or manipulatinginformation according to instructions that haveinformation according to instructions that havebeen given to it.been given to it.

AnAn electronic device that takes input from its user,electronic device that takes input from its user,

stores, processes data & generates the requiredstores, processes data & generates the requiredoutput as per the processing instructions givenoutput as per the processing instructions given

to it user.to it user.


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What Is a Computer?What Is a Computer?

A computer is defined in the following waysA computer is defined in the following ways

By the work it doesBy the work it does

By the kind of information it handlesBy the kind of information it handles By its size and priceBy its size and price

An electronic machine, operating under theAn electronic machine, operating under the

control of instructions stored in its own memory,control of instructions stored in its own memory,that can accept data (input), manipulate datathat can accept data (input), manipulate data

according to specified rules (process), produceaccording to specified rules (process), produceresults (output), and store the results for futureresults (output), and store the results for future

use.use.


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Basic FunctionsBasic Functions

A computer is a device that performs fourA computer is a device that performs fourfunctions: itfunctions: it inputsinputs data (gettingdata (gettinginformation into the machine); itinformation into the machine); it storesstores

data (holding the information before anddata (holding the information before andafter processing); itafter processing); it processesprocesses datadata(performing prescribed mathematical and(performing prescribed mathematical and

logical operations on the information atlogical operations on the information athigh speed); and ithigh speed); and it outputsoutputs data (sendingdata (sendingthe results out to the user via some displaythe results out to the user via some display

method).method).


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Data Processing cycleData Processing cycle


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What Is a Computer?What Is a Computer?

Input Processing Output.Input Processing Output.

Data Processing cycleData Processing cycle

InputInput -- Input Devices feed the computer the rawInput Devices feed the computer the raw

mattermatter facts or data.

facts or data.

ProcessingProcessing the storage of data, numericalthe storage of data, numericalcomparisons, arithmetic operations arecomparisons, arithmetic operations areperformed on data to produce desiredperformed on data to produce desiredresults.results.

OutputOutput the processed data or information isthe processed data or information is sent tosent tothethe out put device connected toout put device connected tocomputercomputer..


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The Information Processing CycleThe Information Processing Cycle

INPUTINPUT OUTPUTOUTPUT

AUXILIARYAUXILIARY

STORAGESTORAGE

PROCESSINGPROCESSING

MAINMAIN

MEMORYMEMORY


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Parts of a ComputerParts of a Computer

There are two basic parts that make up a computer...There are two basic parts that make up a computer...

Hardware Software


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What Is AWhat Is A

Computer System?Computer System? HardwareHardware: the: the

tangible, physicaltangible, physical

equipment that canequipment that canbe seen and touchedbe seen and touchedsuch as:such as: Computer CaseComputer Case MonitorMonitor Keyboard andKeyboard and

MouseMouse Disk DriveDisk Drive SpeakersSpeakers

SoftwareSoftware: the intangible: the intangibleset of instructions that tellsset of instructions that tellsthe computer what to do;the computer what to do;know as programs orknow as programs orsoftware programs.software programs. Two types: application andTwo types: application and

system software programssystem software programs

Data:Data: information enteredinformation enteredinto the computer to beinto the computer to be

processed, which consistsprocessed, which consistsof the following:of the following: Text, numbers, sounds, andText, numbers, sounds, and

imagesimages

People:People: the users of thethe users of thecomputers who enter thecomputers who enter the

data and use the output.data and use the output.


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Computer System HardwareComputer System Hardware

ComponentsComponents Computer system hardware components includeComputer system hardware components include

devices that perform the functions of input, processing,devices that perform the functions of input, processing,communication, data storage and output of ancommunication, data storage and output of an

information systeminformation system..


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Computer HardwareComputer Hardware

CaseCase

Power switchPower switch

Reset switchReset switch

Hard driveHard drive

FloppyFloppy

CD/DVDCD/DVD

Serial portsSerial ports

Parallel portParallel port

USB portUSB port

Keyboard/mouseKeyboard/mouse

Network cardNetwork card

ModemModem

Sound cardSound card

Video cardVideo card

RAMRAM

MotherboardMotherboard

FanFan

CablesCables


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System unitSystem unit

Case that holds the power supply, storage devices, and theCase that holds the power supply, storage devices, and thecircuit boards (including the motherboard).circuit boards (including the motherboard).


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CPU (Central Processing Unit)CPU (Central Processing Unit)

Where the processing in a computer takes place, often calledWhere the processing in a computer takes place, often calledthe brain of the computer.the brain of the computer.


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Computer ProcessingComputer Processing

Once information has been sent to acomputer by one of the input devices its

processed. The computer uses its brain toprocess the information. The computersbrain is called the CPU, or Central

Processing Unit.


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The CPU is also calledthe microprocessor. The

word micro meanssmall. Since the CPUis located on a smallcomputer chip about 1inch square, thatmakes sense!


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Random Access MemoryRandom Access Memory

When a computer processes

information, it uses softwareprograms. Each programrequires a certain amount ofelectronic memory, or RAM

(Random Access Memory) torun correctly.


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RAM is temporary memory. The computerholds information in this memory and gets itwhen it needs it.

If a computer has more RAM, it can solveproblems and process information faster! Ifyoure updating your computer, more RAM is agreat thing to add!


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ReadRead--Only MemoryOnly Memory

A second kind of computer memory is

ROM, which stands for Read-OnlyMemory. This memory is permanent. Theinformation there was put there when the

computer was made. The computer needs theinformation in its ROM memory in orderto function.


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Input DevicesInput Devices

Units that gather information and transform thatUnits that gather information and transform that

information it into a series of electronic signalsinformation it into a series of electronic signalsfor the computer.for the computer.


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KeyboardKeyboard

An arrangement of letters, numbers, and special functionAn arrangement of letters, numbers, and special functionkeys that act as the primary input device to the computer.keys that act as the primary input device to the computer.


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MouseMouse

An input device that allows the user to manipulate objects onAn input device that allows the user to manipulate objects onthe screen by moving the device along the surface of a desk.the screen by moving the device along the surface of a desk.


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Sound CardSound Card

A circuit board that gives the computer the ability to acceptA circuit board that gives the computer the ability to acceptaudio input, play sound files, and produce audio outputaudio input, play sound files, and produce audio outputthrough speakers or headphones.through speakers or headphones.


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ModemModem

A device that sends and receives data to and from computersA device that sends and receives data to and from computersover telephone lines.over telephone lines.


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Output DevicesOutput Devices

Devices that display, print, or transmit theDevices that display, print, or transmit the

results of processing from the computersresults of processing from the computersmemory.memory.


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MonitorMonitor

Display device that forms an image by converting electrical signals from the computer intoDisplay device that forms an image by converting electrical signals from the computer intopoints of colored light on the screen.points of colored light on the screen. ResolutionResolution

The density of the grid used to display or print text and graphics; the greater theThe density of the grid used to display or print text and graphics; the greater thehorizontal and vertical density, the higher the resolution.horizontal and vertical density, the higher the resolution.

PixelsPixels

The smallest unit in a graphic image; computer display devices use a matrix of pixels toThe smallest unit in a graphic image; computer display devices use a matrix of pixels todisplay text and graphics.display text and graphics.


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SpeakersSpeakers

Output devices that receive signals from the computersOutput devices that receive signals from the computerssound card to play music, narration, or sound effects.sound card to play music, narration, or sound effects.


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What are all those parts inside mycomputer and what do they do???


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Computer HardwareComputer Hardware

Hard DriveHard Drive

MotherboardMotherboard

Sound Card and Video CardSound Card and Video Card Memory CardMemory Card

Power SupplyPower Supply

NIC CardNIC Card BIOSBIOS


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Hard Disk DriveHard Disk Drive

The Hard Disk Drive is a magnetic storage device.All the computer programs and files you create and

save are located there. This is permanent storage (atleast until you uninstall software or delete a file).The hard drive is normally signified by the driveletter C. Todays hard drives can store a HUGE

amount of information.


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Inside the Hard Disk Drive caseyoull find circular disks thatare made of steel. On the disks,there are many tracks, orcylinders. An electronicreading device called the headpasses back and forth over thecylinders, reading informationfrom the disk or writing to it.


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Hard Disk Drives useMagnetic Recording

Techniques. The magneticmedium can be easily erasedand rewritten and willremember the magnetic

change patterns stored on itfor many years!


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Hard Disk Drives can spin at 7200 or more rpms(Revolutions Per Minute). That means in one

minute, the hard drive spins around more than7200 times!


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The MotherboardThe Motherboard


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Your computer couldnt work without the motherboard. Itties everything together! It allows every part of your

computer to receive power and communicate with eachother. Everything that runs the computer or enhancesits performance is either part of the motherboard or plugsinto one of its expansion slots or ports.


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Sound and Video CardsSound and Video Cards

Sound and Video Cards are OutputDevices. They contain special circuitsthat allow your computer to play soundsand display graphics on your monitor.


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Power SupplyPower Supply

If there is any one component that is absolutely vitalto the operation of a computer, it is the power supply!Without it, a computer is just a box full of plastic andmetal. The power supply converts the alternatingcurrent (AC) line to the direct current (DC) needed bythe computer.


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You can see the powersupply from the back of

your computer because ofthe power cord and thecooling fan.Computers put out a LOT

of heat and need the fanto keep them fromoverheating.


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Network Interface CardNetwork Interface Card

A NIC card (NetworkInterface Card) allows yourcomputer to talk to othercomputers! A cable calledCat5 is plugged into theNIC card and yourcomputer can then beattached to a network andbe on the internet!


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BIOS CHIPBIOS CHIP

A BIOS chip (Basic InputOutput System) is a veryimportant computer

component. In simple terms,the BIOS chip wakes up thecomputer when you turn iton and reminds it what parts

it has and what they do!


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Bytes, Kilobytes,Bytes, Kilobytes,

Mega

bytesa

nd Giga

bytesMega

bytesa

nd Giga

bytes

Byte 8 Bits=1 byteByte 8 Bits=1 byte

KB Kilobyte=1,000 bytesKB Kilobyte=1,000 bytes

MB Megabyte=1,000,000MB Megabyte=1,000,000

(1 million) bytes(1 million) bytes

GB Gigabyte=1,000,000,000GB Gigabyte=1,000,000,000(1 billion) bytes(1 billion) bytes


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Ive heard those words,Ive heard those words,

but wha

tsa

B

yte??but wha

tsa

B

yte??All the information that moves

through your computer is basedon 2 commands.Thats all, just two. The twocommands are ON and OFF.

They are symbolized by 1s and0s.


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Thats right! The only information yourcomputer can understand is ON (1) and OFF(0)!

The millions of combinations of those twocommands given in series are what makesyour computer work.


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The memory chips in yourcomputer are divided intothousands of tinycompartments called bits.

Each and every bit has anelectronic switch, or gate.ON means the gate is openand letting electricitythrough.


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Remember, the computer readsO

N or openbits or switches as the number 1. Closedswitches are OFF because electricity cantget through.

The computer reads OFF bits or switchesas 0.


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It is by grouping these bits together to form 1/0commands that data is formed. Remember

bytes? Eight bits are grouped together to formone byte.In that group of 8, there are 256 possiblecombinations of 1/0.

The grouping of 1/0 within a byte is calledBinary Code.Binary Code is the language of computers.


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Here is an example of Binary Code: when youtype in the letter A on your keyboard, electrical

signals are sent from the keyboard to the CPU.The CPU turns the signals into Binary Code.Then the computer reads the code and sends it onto the monitor to display the letter A. All of thathappens in an instant!


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So what about Megabytesand Gigabytes????


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Megabytes and GigabytesMegabytes and GigabytesOne megabyte equals one million bytes.So, a computer with 512 megabytes ofRAM (Random Access Memory) means

the computer can handle 512,000,000(512 million) bytes of RAM.

Hard disk space is also measured in

bytes. So, a 200 GB Hard Disk Drivehas 200,000,000,000 (200 billion) bytesfor storing memory!


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To get an idea of howmuch on/off (1/0) data acomputer can store,imagine pressing anykey 1 billion times. How

long would it take?


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You would have to press a key 5 times asecond non-stop for over 6 YEARS to

reach 1 billion keystrokes.One billion keystrokes equals just1 GB of memory!

Think about that the next time you thinka webpage is loading too slowly!


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Types of ComputersTypes of Computers

B Si & C iB Si & C i


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By Size & CapacityBy Size & Capacity

Based on PerformanceBased on Performance speed ofspeed ofprocessing instruction, size & storage.processing instruction, size & storage.

Micro computerMicro computer

WorkstationWorkstation

Mainframe computerMainframe computer

Super computerSuper computer


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By Size & CapacityBy Size & Capacity --

MicrocomputerMicrocomputer

1. A microcomputer1. A microcomputer is a computer that has ais a computer that has aMicroprocessorMicroprocessor chip as its CPU. They are oftenchip as its CPU. They are oftencalledcalled personal computerspersonal computers because they are designedbecause they are designedto be used by one person at a time.to be used by one person at a time.

Personal computers are typically used at home, atPersonal computers are typically used at home, atschool, or at a business.school, or at a business.

Popular uses for microcomputers include wordPopular uses for microcomputers include wordprocessing, surfing the web, sending and receiving eprocessing, surfing the web, sending and receiving e--

mail, spreadsheet, calculations, databasemail, spreadsheet, calculations, databasemanagement, editing photographs, creating graphics,management, editing photographs, creating graphics,and playing music or games.and playing music or games.



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Personal computers come in two majorPersonal computers come in two major

varieties depending on size storage, speedvarieties depending on size storage, speed&& portablesportables ,,

Desktop computersDesktop computers

Portable computersPortable computers::

1.11.1Desktop computersDesktop computers are larger and notare larger and notmeant to be portable. They usually sit inmeant to be portable. They usually sit inone place on a desk or table and areone place on a desk or table and areplugged into a wall outlet for power.plugged into a wall outlet for power.


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Desktop computersDesktop computers

The case of the computer holds theThe case of the computer holds the mothermotherboardboard,, drivesdrives,, power supplypower supply, and, and expansionexpansioncardscards. This case may lay flat on the desk, or it. This case may lay flat on the desk, or itmay be a tower that stands vertically (on themay be a tower that stands vertically (on the

desk or under it).desk or under it). The computer usually has a separate monitorThe computer usually has a separate monitor

(either a(either a CRT or LCDCRT or LCD) although some designs) although some designshave a display built into the case.have a display built into the case.

A separate keyboard and mouse allow the userA separate keyboard and mouse allow the userto input data and commands.to input data and commands.


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Desktop ComputerDesktop Computer


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PortablesPortables Various types of Portables:Various types of Portables:

1.21.2 LaptopLaptop oror notebooknotebookcomputers are small andcomputers are small andlightweight enough to be carried around with thelightweight enough to be carried around with theuser.user.

They run on battery power, but can also be pluggedThey run on battery power, but can also be plugged

into a wall outlet. They typically have a builtinto a wall outlet. They typically have a built--in LCDin LCDdisplay that folds down to protect the display whendisplay that folds down to protect the display whenthe computer is carried around.the computer is carried around.

They also feature a builtThey also feature a built--in keyboard and some kindin keyboard and some kind

of builtof built--in pointing device (such as a touch pad).in pointing device (such as a touch pad).


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Laptop / NotebookLaptop / Notebook


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PDAs and Palmtop ComputersPDAs and Palmtop Computers

AA Personal Digital AssistantPersonal Digital Assistant ((PDAPDA)) is a handheldis a handheldmicrocomputer that trades off power for small sizemicrocomputer that trades off power for small sizeand greater portability.and greater portability.

They typically use a touchThey typically use a touch--sensitive LCD screen forsensitive LCD screen forboth output and input (the user draws characters andboth output and input (the user draws characters and

presses icons on the screen with a stylus).presses icons on the screen with a stylus). PDAs communicate with desktop computers andPDAs communicate with desktop computers and

with each other either by cable connection, infraredwith each other either by cable connection, infrared(IR) beam, or radio waves.(IR) beam, or radio waves.

PDAs are normally used to keep track ofPDAs are normally used to keep track ofappointment calendars, toappointment calendars, to--do lists, address books,do lists, address books,and for taking notes.and for taking notes.


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Personal Digital AssistantPersonal Digital Assistant


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Palmtop ComputersPalmtop Computers

AA palmtoppalmtop oror handheld PChandheld PC is a very smallis a very smallmicrocomputer that also sacrifices power for smallmicrocomputer that also sacrifices power for smallsize and portability.size and portability.

These devices typically look more like aThese devices typically look more like a tiny laptoptiny laptop

than a PDA, with a flipthan a PDA, with a flip--up screen and smallup screen and smallkeyboard. They may use Windows CE or similarkeyboard. They may use Windows CE or similaroperating system for handheld devices.operating system for handheld devices.

Some PDAs and palmtops contain wirelessSome PDAs and palmtops contain wireless

networking or cell phone devices so that users cannetworking or cell phone devices so that users cancheck echeck e--mail or surf the web on the move.mail or surf the web on the move.


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Palmtop ComputersPalmtop Computers


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2.Workstation /Servers2.Workstation /ServersAA workstationworkstation is a powerful, highis a powerful, high--endend

microcomputer. They contain one or moremicrocomputer. They contain one or moremicroprocessor CPUs. They may be used bymicroprocessor CPUs. They may be used bya singlea single--user for applications requiring moreuser for applications requiring more

power than a typical PC (rendering complexpower than a typical PC (rendering complexgraphics, or performing intensive scientificgraphics, or performing intensive scientificcalculations).calculations).

Alternately, workstationAlternately, workstation--classclass

microcomputers may be used asmicrocomputers may be used as serverservercomputers that supply files tocomputers that supply files to clientclientcomputers over a network.computers over a network.


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Workstation /ServersWorkstation /Servers

This class of powerful microcomputers canThis class of powerful microcomputers canalso be used to handle the processing foralso be used to handle the processing formany users simultaneously who aremany users simultaneously who areconnected via terminals; in this respect,connected via terminals; in this respect,highhigh--end workstations have essentiallyend workstations have essentiallysupplanted the role of minicomputerssupplanted the role of minicomputers

3 Main Frame Computer:3 Main Frame Computer:


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3.Main Frame Computer:3.Main Frame Computer:

AA mainframe computermainframe computer is a large, powerfulis a large, powerfulcomputer that handles the processing for manycomputer that handles the processing for manyusers simultaneously (up to several hundred users).users simultaneously (up to several hundred users).

The name mainframe originated afterThe name mainframe originated after

minicomputers appeared in the 1960s to distinguishminicomputers appeared in the 1960s to distinguishthe larger systems from the smaller minicomputers.the larger systems from the smaller minicomputers.

Users connect to the mainframe using terminals andUsers connect to the mainframe using terminals andsubmit their tasks for processing by the mainframesubmit their tasks for processing by the mainframe

Main frame Computer:Main frame Computer:


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Main frame Computer:Main frame Computer:

They are used in situations where a companyThey are used in situations where a companywants thewants the processing power and informationprocessing power and information

storage in a centralized locationstorage in a centralized location..

Mainframes are also now being used as highMainframes are also now being used as high--capacity server connection for networks withcapacity server connection for networks withmany client workstations.many client workstations.

Examples:H

igh process likeExamples:H

igh process like --AT

MAT

M

a n rame computer t sa n rame computer t s


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pp

zz--series computer is about 6 feetseries computer is about 6 feet

tall)tall)

4 Super computer:4 Super computer:


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4. Super computer:4. Super computer:

AA supercomputersupercomputer is mainframe computer thatis mainframe computer that

has been optimized for speed and processinghas been optimized for speed and processingpower.power.

Handles mostly complex scientific &Handles mostly complex scientific &

statistical applications / program.statistical applications / program. High technologyHigh technology -- used for special purpose.used for special purpose.

High memory capacityHigh memory capacity > 8.4 millions> 8.4 millions


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Supercomputers are used for highly calculationSupercomputers are used for highly calculation--intensive tasks such as problems involving quantumintensive tasks such as problems involving quantum

mechanical physics, Weather Forecasting climatemechanical physics, Weather Forecasting climateresearch (including research into global warming),research (including research into global warming),molecular modeling (computing the structures andmolecular modeling (computing the structures andproperties of chemical compounds, biologicalproperties of chemical compounds, biological

macromolecules, polymers, and crystals)macromolecules, polymers, and crystals) physical simulations (such as simulation of airplanesphysical simulations (such as simulation of airplanes

in wind tunnels simulation of the detonation ofin wind tunnels simulation of the detonation ofnuclear weapons, and research into nuclear fusion).nuclear weapons, and research into nuclear fusion).

Super computer:Super computer:


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Super computer:Super computer: Major universities, military agencies andMajor universities, military agencies and

scientific research laboratories are heavyscientific research laboratories are heavyusers.users.

The most famous series of supercomputersThe most famous series of supercomputers

were designed by the company founded andwere designed by the company founded andnamed after Seymour Cray. Thenamed after Seymour Cray. The CrayCray--11waswas

built in the 1976 and installed at Los Alamosbuilt in the 1976 and installed at Los Alamos

National Laboratory.National Laboratory.

Super computer The CraySuper computer The Cray -- 1 was the1 was the


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upe co pu e e yupe co pu e e y s es e

world's fastest computer from 1985 toworld's fastest computer from 1985 to

1989.1989.

ABlue Gene/L cabinet. IBM's BlueABlue Gene/L cabinet. IBM's Blue


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//

Gene/L is the fastest supercomputerGene/L is the fastest supercomputer

in the world.in the world.

basic of computer system

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