chapter 2 computer hardware(part 1)-basic component & power supply

7/31/2019 CHAPTER 2 Computer Hardware(Part 1)-Basic Component & Power Supply

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2.1BASIC COMPONENT OFCOMPUTER SYSTEM

The most important part of every

computer is the centralprocessing unit (CPU, or simply aprocessor).

The CPU consists of two (2) mainparts: ControlUnit and Arithmetic Logic

Unit(ALU).


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Cont

Control unit : is the circuitry thatcontrols the flow of information throughthe processor, and coordinates the

activities of the other units within it. In away, it is the "brain within the brain", asit controls what happens inside theprocessor, which in turn controls the restof the PC.

ALU : is a digital circuit thatperforms arithmetic and logical operat

ions.


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Cont

Main memory- is refer to Random AccessMemory (RAM) thatstores programs anddata currently being used by the CPU.

Disk storage is refer to Hard drive thatstore programs and data that are notcurrently being used by the CPU. Hard

drive stores much more data than atypical PCs RAM up to hundreds ofgigabytes.

Peripheral devices eg. Graphic

card,sound card.


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Common Components ofComputer HardwareThe physical components that work

together to make a computer system or

network

For example : Monitor, Keyboard,Motherboard, Hard disk, etc


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Common Components ofComputer Software

Computer programs that perform specifictask

For example: Operating systems, Programapplication, hardware drivers (special

programs that tell the operating system

how to use the hardware).


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Common Components ofComputer Firmware

Software that has been permanentlyplaced in a hardware component

For example : BIOS CHIP


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Describe how the PC works

Computer functions through four stages: Input Processing

OutputStorage

Knowing which parts participate in aparticular stage of the computing process

enables you to troubleshoot on afundamental and decisive level


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Input devices to enter the data orinformation into computer : Keyboardand mouse.

Processing devices to processinformation or data.

: microprocessor or CPU and RAM.

Output devices display the data orinformation.

: monitor and printer.

Storage devices store the data and


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Hardware Used for Input and Output

Connects to computer case by ports (eg, serial,parallel, USB, game, keyboard, mouse)

Popular input devices: Keyboard

Mouse

Popular output devices: Monitor

Printer


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The Complete PC


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Various primary storagedevices and media

There are two types of memory used incomputers:

Read-only Memory (ROM) can be read but

cannot be written to. ROM is used topermanently store data and programsthat are always needed. Contents ofmemory are preserved even when there is

no power (non-volatile). Random Access Memory (RAM) can be

read from and written to. RAM is used as a

temporary data storage location.


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ROM

ROM (Read-only Memory)- Programmed by the chip manufacturer

- Not erasable

PROM (Programmable Read-only Memory)- Programmed by chip manufacturer- Not erasable once programmed

EPROM (Erasable Programmable Read-onlyMemory)- Programmed by the OEM or user- Erasable by the user with ultraviolet

light


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ROM

EEPROM (Electrically ErasableProgrammable Read-only Memory; alsoknown as Flash Memory)

- Programmed by the chipmanufacturer or user

- Erasable and re-programmable by

the user with software (electronically)- Stores data even without power

- Limit to how many times the data inan EEPROM chip can be flashed

(modified)


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RAM

Static RAM (SRAM)- No refresh required (non-volatile, meaningthat no power is required to retain memorycontents)

- Comes on motherboard (cache memory) aschips, or COAST (cache-on-a-stick) modules- No memory addresses assigned

Dynamic RAM (DRAM)

- Requires constant refresh (volatile, meaning

that power is required to retain memorycontents)

- Memory addresses assigned

- Used as the main system memory andmemory on other components

- Is slower than SRAM


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Word size

The number of bits that a CPU can process at onetime.Processors with many different w

ord sizes have existed thoughpowersof two (8, 16, 32, 64) .


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Secondary storage devicesand media

1) Magnetic tape

is a medium for magnetic recording,made of a thin magnetizable coating on

a long, narrow strip of plastic. Devices that record and play back audio

and video using magnetic tape are tape

recorders and video tape recorders. A device that stores computer data on

magnetic tape is a tape drive.


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2) Hard Disk

A hard disk is a thick magnetic diskencased in a thicker protective shell

Typically install inside the computer

Can hold more information compareto other storage devices

Type of hard drive interface- IDE - EIDE (PATA)

- SATA - SCSI


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3) Optical disk

is a flat, usually circular disc whichencodes binary data (bits)

An optical disc is designed to support one

of three recording types: read-only(e.g.: CD and CD-ROM), recordable(write-once, e.g. CD-R), or re-recordable(rewritable, e.g. CD-RW).

Optical discs are most commonly used forstoring music (e.g. for use in a CDplayer), video (e.g. for use in a DVDplayer), or data and programsfor personal computers(PC)


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Optical Media

Optical media into two groups:CDs and DVDs

CDs store around 700 MB and come in threevarieties: CD-ROM (read only memory: you cant change the

data on them)

CD-R (recordable:you can change the data once)

CD-RW (rewritable: you can change thedata on themover and over)

DVDs store much more dataaround 4 GB


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Input devices for particularpurpose Optical mark reader.(OMR)

Is a device that interprets pencil markson paper media such as surveys or test

answer forms. Character reader

i) Optical Character Recognition(OCR)

Is the machine recognition of printedcharacters. OCR systems can recognizemany different OCR fonts, as well astypewriter and computer-printedcharacters.


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ii) Magnetic Ink Character Recognition(MICR)

is a character recognition technology

used primarily by the banking industryto facilitate the processing ofcheques

and makes up the routing number andaccount number at the bottom of acheck.

Input devices for particularpurpose
http://en.wikipedia.org/wiki/Chequehttp://en.wikipedia.org/wiki/Cheque


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Input devices for particularpurpose Light pen

is the form of a light-sensitive wandused in conjunction with a computer's

CRT TV set or monitor.Touch Terminal

can detect the presence and location of

a touch within the display area. Voice data entry

is speech recognition software, which

turns

d i f i l
http://en.wikipedia.org/wiki/Cathode_ray_tubehttp://en.wikipedia.org/wiki/Computer_displayhttp://en.wikipedia.org/wiki/Computer_displayhttp://en.wikipedia.org/wiki/Cathode_ray_tube


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Input devices for particularpurpose Pads and tablets

Point of sale

Bar code

But usually input devices that we know:

- keyboard

- mouse

- scanner

- microphone


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2.2 POWER SUPPLY

Takes electricity from the wall socketand transforms it into electricity to runthe motherboard and other internal

componentsThe power supply unit (PSU) takes over,converting high-voltage AC into severalDC voltages (notably, 5.0, 12.0, and 3.3volts) usable by the delicate interiorcomponents

PC uses the 12.0-volt current to powermotors on devices such as hard drivesand CD-ROM drives, and it uses the 5.0-volt and 3.3-volt current for support of


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Power Supplies


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Power to the Motherboard

Use a 20- or 24-pin P1 power connector.Some motherboards may require special4-, 6-, or 8-pin connectors to supply

extra power


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Power to Peripherals: Molex

Molex Connectors

The most common type of powerconnection for devices

Need 5-volts or 12-volts of power is theMolexconnector

The Molex connector has notches, calledchamfers, that guide its installation


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Power to Peripherals: Mini Connectors

Mini Connectors

A second type of connector, called a miniconnector

Supplies 5 and 12 volts to peripherals,although only floppy disk drives in modernsystems use this connector


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Power to Peripherals: SATA PowerConnectors

SATA Power ConnectorsSerial ATA (SATA) hard drives need a special 15-

pin SATA power connector

The larger pin count supports the SATA hot-swappable feature, and 3.3 V, 5.0 V, and 12.0 Vdevices. SATA power connectors are L shaped,making it almost impossible to insert oneincorrectly into a SATA drive

No other device on your computer uses theSATA power connector


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Power to Peripherals: AuxiliaryConnector

Motherboard power connectorCommonly called anAUXconnector

To supply increased 3.3- and 5.0-volt

current to the motherboard


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Power Supply Form Factors

All use standard ATX connectors, but differin size and shape from standard ATXpower suppliesTFX12V A small power form factor optimized

for low-profile ATX systemsSFX12V A small power form factor optimizedfor systems using FlexATX motherboards

CFX12V An L-shaped power supply optimizedfor Micro BTX systems

LFX12V A small power form factor optimized forlow-profile BTX systems

P i Y lf A i


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Protecting Yourself AgainstElectricity

Turn off power and unplug computer

Always use a ground bracelet

Never touch inside of a computer while itis turned on

Never remove cover or put your handsinside monitor or power supply


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Static Electricity (or ESD)

Can cause catastrophic failure or upset failure

Protection against ESD

Ground bracelet or static strap

Ground mats

Static shielding bags


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Ground Bracelet

U di Y P


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Upgrading Your PowerSupply

Sometimes necessary when you

add new devices

Easiest way to fix a power supplyyou suspect is faulty is to replace it


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Troubleshooting the PowerSystem: General Guidelines

Any burnt parts or odors?

Everything connected and turned on?Loose cable connections? Computerplugged in?

All switches turned on? Wall outlet

good?

If fan is not running, turn off computer:Connections to power supply secure?

Cards securely seated?


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Troubleshooting the PowerSystem: General Guidelines

Check for correct wire connections to

motherboard

Remove nonessential expansion cards oneat a time

Vacuum entire unit


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Troubleshooting an ATX Power Supply


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Preventing Overheating

Preventing Overheating


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Preventing Overheating(continued)


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Energy Star Systems(The Green Star)

Satisfy energy-conserving standardsof the US Evironment Protection

Agency(EPA).

Generally have a standby program

that switches device to sleep modewhen not in use

Apply to computers, monitors,

printers, copiers, and fax machines

Power Management


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Power ManagementMethods Advanced Power Management (APM)

AT Attachment (ATA) for IDE drives

Display Power Management Signaling (DPMS)standards for monitors and video cards

Advanced Configuration and Power Interface(ACPI)


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Changing Power Options


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UPS

UPS - uninterruptible power supply(UPS)Protects your computer (and, more

importantly, your data) in the event of apower sag or power outage

A UPS essentially contains a big batterythat will provide AC power to yourcomputer, regardless of the powercoming from the AC outlet

Uninterruptible Power


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Uninterruptible PowerSupplies

BenefitsCondition line for brownouts and spikesProvide backup power during a blackoutProtect against very high potentially

damaging spikes ConsiderationsCostUPS ratingDegree of line conditioningWarranty and service policies

chapter 2 computer hardware(part 1)-basic component & power supply

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