computer hardware

Computer System Computer System HardwareHardware

Computer System Computer System HardwareHardware

Input Output Storage

OBJECTIVESOBJECTIVES

Identify and describe the most Identify and describe the most common input devices.common input devices.

Identify and describe the most Identify and describe the most common output devices.common output devices.

Identify and describe storage devices.Identify and describe storage devices. Identify and describe how input and Identify and describe how input and

output devices are connected to the output devices are connected to the computer.computer.

Input and Output DevicesInput and Output Devices

Input devices enable a user to input data Input devices enable a user to input data and commands to the computer to be and commands to the computer to be processed.processed.

Output Devices enable the computer to Output Devices enable the computer to give or show you the results of its give or show you the results of its processing.processing.

Some Devices can perform both input and Some Devices can perform both input and output operations.output operations.

Input Devices--- The keyboardInput Devices--- The keyboard

The keyboard is the The keyboard is the most widely used most widely used input device.input device.

o As you press key on As you press key on the keyboard, an the keyboard, an electrical signal electrical signal representing that key representing that key is sent to computer.is sent to computer.

o Keyboards are Keyboards are divided into sections. divided into sections.

Input Devices--- The Keyboard (cont.)Input Devices--- The Keyboard (cont.)

Typewriter Keys: The standard alphabetic and Typewriter Keys: The standard alphabetic and numeric characters you find on a typewriternumeric characters you find on a typewriter

Function Keys: Special keys that perform Function Keys: Special keys that perform some specific function for the application some specific function for the application being runbeing run

Numeric Keypads: used for mathematical Numeric Keypads: used for mathematical operationsoperations

Directional Keys: used to move the cursor Directional Keys: used to move the cursor around the screen around the screen

Input Devices--- The MouseInput Devices--- The Mouse

The mouse is a pointing device that rolls The mouse is a pointing device that rolls around on a flat surface and controls the around on a flat surface and controls the location of the pointer on the screen.location of the pointer on the screen.

The mouse performs the following The mouse performs the following functions:functions: Pointing:Pointing: Placing the on-screen pointer Placing the on-screen pointer

at a specific placeat a specific place Clicking:Clicking: Pressing and releasing the Pressing and releasing the

mouse buttonmouse button

Input Devices—The Mouse (cont.)Input Devices—The Mouse (cont.) Mouse functions (cont.)Mouse functions (cont.)

Dragging:Dragging: Holding down the mouse Holding down the mouse button and dragging an object to a new button and dragging an object to a new location by dragging the mouselocation by dragging the mouse

Double-clicking:Double-clicking: Pressing and Pressing and releasing the mouse button twice very releasing the mouse button twice very quicklyquickly

Right-clicking:Right-clicking: Pressing the right Pressing the right mouse buttonmouse button

Other Pointing DevicesOther Pointing Devices

Other devices that control the on-screen Other devices that control the on-screen pointer:pointer: Trackball:Trackball: This is like a mouse turned This is like a mouse turned

upside down. You roll a ball around with upside down. You roll a ball around with your fingers to control the location of the your fingers to control the location of the pointer.pointer.

• These frequently are found on These frequently are found on notebook computers.notebook computers.

Other Pointing Devices (cont.)Other Pointing Devices (cont.)

Joystick and wheel:Joystick and wheel: Joysticks Joysticks consist of a metal or plastic consist of a metal or plastic handle mounted on a base handle mounted on a base that you can move in any that you can move in any direction to move the pointer direction to move the pointer or other object.or other object.• These typically are used These typically are used

for video games.for video games.• Most have buttons that can Most have buttons that can

be pushed or clicked be pushed or clicked to control input/output.to control input/output.

Other Input DevicesOther Input Devices

Pointing stick:Pointing stick: A pressure-sensitive A pressure-sensitive device that resembles a pencil eraser; device that resembles a pencil eraser; found mostly on notebook computersfound mostly on notebook computers

Graphics tablet:Graphics tablet: A flat drawing surface A flat drawing surface connected to the computerconnected to the computer The user draws on the surface, and the The user draws on the surface, and the

figures or writing on the tablet can be figures or writing on the tablet can be input to the computer for processing.input to the computer for processing.

Other Input Devices (cont.)Other Input Devices (cont.)

Touch display:Touch display: Screens that contain Screens that contain pictures or shapes that the user can pictures or shapes that the user can press to input that datapress to input that data

Stylus/digital pen:Stylus/digital pen: Used with mobile Used with mobile devices to input datadevices to input data

Touchpad:Touchpad: Used mostly in Used mostly in laptop/notebook computerslaptop/notebook computers


Audio/voice input:Audio/voice input: Inputting sound Inputting sound and/or voiceand/or voice These usually require a microphone and These usually require a microphone and

special voice recognition software to be special voice recognition software to be installed on the computer.installed on the computer.


Scanners:Scanners: Devices that can convert a Devices that can convert a graphical image into a digital image and input graphical image into a digital image and input it to the computer it to the computer Types of scanners includeTypes of scanners include

• Image scanners for scanning images and textImage scanners for scanning images and text• Bar code scanners to read product bar codesBar code scanners to read product bar codes• Magnetic scanners to read the magnetic strip on Magnetic scanners to read the magnetic strip on

a credit carda credit card


Digital cameras:Digital cameras: Used to take pictures Used to take pictures and store them on a magnetic disk and store them on a magnetic disk instead of on filminstead of on film Their images can be input directly into Their images can be input directly into

the computer.the computer. Video input:Video input: Input from a camcorder or Input from a camcorder or

VCR using video capture cardsVCR using video capture cards


Biometric input:Biometric input: Uses fingerprint, Uses fingerprint, face, handwriting, face, handwriting, and voice for and voice for identificationidentification

Magnetic Storage DevicesMagnetic Storage Devices

Floppy disks:Floppy disks: Small, portable disks that hold a Small, portable disks that hold a limited amount of datalimited amount of data

Hard disks:Hard disks: Large-capacity and fast-access Large-capacity and fast-access storage devicesstorage devices

Zip disks:Zip disks: Auxiliary storage devices that can Auxiliary storage devices that can hold large quantities of data and can be portablehold large quantities of data and can be portable

Magnetic tape drives:Magnetic tape drives: Used for making system Used for making system backups and storing large quantities of databackups and storing large quantities of data

Optical Storage DevicesOptical Storage Devices

CD-DA:CD-DA: Audio CD Audio CD CD-R:CD-R: This drive This drive

allows you to read allows you to read and to write to a and to write to a compact diskcompact disk

CD-ROM:CD-ROM: Can hold Can hold large amounts of large amounts of data, but is read-data, but is read-only accessonly access

Optical Storage Devices (cont.)Optical Storage Devices (cont.)

CD-RW:CD-RW: Can be written on several times Can be written on several times DVD-ROM:DVD-ROM: Read-only DVD format Read-only DVD format DVD-R:DVD-R: Similar to CD, but holds more data; Similar to CD, but holds more data;

read-onlyread-only DVD-RW:DVD-RW: Can be written on several times Can be written on several times PhotoCDPhotoCD: Used for storing digital : Used for storing digital

photographs on a CDphotographs on a CD

Solid-State Storage MediaSolid-State Storage Media

Non-volatile removable mediaNon-volatile removable media Miniature mobile mediaMiniature mobile media

Uses integrated circuitsUses integrated circuits USB flash driveUSB flash drive

Connects to the computer via a Connects to the computer via a USB portUSB port

Caring for Storage MediaCaring for Storage Media

To safeguard your data from damage, To safeguard your data from damage, follow these tips when dealing with follow these tips when dealing with removable media:removable media: Keep away from magnetic fields.Keep away from magnetic fields. Avoid extreme temperatures.Avoid extreme temperatures. Never try to disassemble the case.Never try to disassemble the case. Remove media from drive when not Remove media from drive when not

being used.being used.

Caring for Storage Media (cont.)Caring for Storage Media (cont.)

Tips for dealing with storage media Tips for dealing with storage media (cont.)(cont.) Write-protect important data.Write-protect important data. Hold optical disks at their edges.Hold optical disks at their edges. Never remove the media from the drive Never remove the media from the drive

if the access light is on.if the access light is on. Keep disks in a sturdy case when Keep disks in a sturdy case when

transporting them.transporting them.

Output Devices—MonitorsOutput Devices—Monitors

MonitorsMonitors are used to display video are used to display video output to a user.output to a user.

Monitors may be monochromatic or Monitors may be monochromatic or color.color. Monochromatic monitors display output Monochromatic monitors display output

in a single-color display.in a single-color display.

Output Devices—Monitors (cont.)Output Devices—Monitors (cont.)

Factors that influence the quality of a Factors that influence the quality of a monitormonitor Screen size: The diagonal measurement Screen size: The diagonal measurement

in inches of the display areain inches of the display area Resolution: The number of pixels that Resolution: The number of pixels that

can be displayed in the display areacan be displayed in the display area Dot pitch: The distance between each Dot pitch: The distance between each

pixel in the display areapixel in the display area

Typical Computer MonitorTypical Computer Monitor

Gas plasma

LCD

This figure shows a typical computer monitor on a swivel stand that can be adjusted for viewing comfort.

Output Devices—PrintersOutput Devices—Printers

Printers are used to create a hard copy Printers are used to create a hard copy of a document or image.of a document or image. Printers vary by speed, quality, and Printers vary by speed, quality, and

price.price.

Output Devices—Printers (cont.)Output Devices—Printers (cont.)

The most popular types of printers areThe most popular types of printers are Laser:Laser: Produce images using the same Produce images using the same

techniques as copier machinestechniques as copier machines Ink jet:Ink jet: Use fine nozzles to spray ink onto the Use fine nozzles to spray ink onto the

page as the paper passes throughpage as the paper passes through Dot matrix:Dot matrix: Work similarly to a typewriter in Work similarly to a typewriter in

that ink is transferred to the paper by some that ink is transferred to the paper by some part of the printer striking a ribbon to transfer part of the printer striking a ribbon to transfer an imagean image

Laser PrinterLaser Printer

This figure provides an overview of a laser printer.

Ink Jet PrinterInk Jet Printer

This figure provides an overview of an ink jet printer.

Other Types of Output DevicesOther Types of Output Devices

Speakers and headsetsSpeakers and headsets Fax machines and fax modemsFax machines and fax modems Multifunctional devicesMultifunctional devices

Contain a variation of output optionsContain a variation of output options Data projectorsData projectors

Connecting I/O Devices to the Connecting I/O Devices to the ComputerComputer

Input and output devices must be connected Input and output devices must be connected to the computer before they can be used.to the computer before they can be used.

Connecting I/O devices to the computer:Connecting I/O devices to the computer: Plug the device into an existing socket or port Plug the device into an existing socket or port

on the back of the computer.on the back of the computer. Install an expansion card with the port you Install an expansion card with the port you

need included on the back of the card.need included on the back of the card. Connect wirelessly.Connect wirelessly.

SummarySummary

Input devices enable you to input data and Input devices enable you to input data and commands into the computer.commands into the computer.

The most common input devices are the The most common input devices are the keyboard and mouse.keyboard and mouse.

Other types of input devices include trackball, Other types of input devices include trackball, joystick and wheel, pointing stick, graphics joystick and wheel, pointing stick, graphics tablet, touch display screen, stylus, voice tablet, touch display screen, stylus, voice recognition devices, touchpad, scanner, digital recognition devices, touchpad, scanner, digital camera, video input, and biometric input.camera, video input, and biometric input.

Summary (cont.)Summary (cont.)

To maintain a permanent copy of data, To maintain a permanent copy of data, you should store it on some type of you should store it on some type of storage medium.storage medium.

The three categories of storage media The three categories of storage media are magnetic storage, optical storage, are magnetic storage, optical storage, and solid-state storage.and solid-state storage.

Monitors and printers are examples of Monitors and printers are examples of output devices.output devices.


Monitors produce soft copy.Monitors produce soft copy. Printers are used to produce a paper or Printers are used to produce a paper or

hard copy of the processed result.hard copy of the processed result. Criteria for selecting a printer include Criteria for selecting a printer include

speed, print quality, and cost.speed, print quality, and cost. Input and output devices must be Input and output devices must be

physically connected to the computer.physically connected to the computer.


Some input devices communicate with Some input devices communicate with the computer through a physical the computer through a physical connection.connection.

Wireless devices communicate with the Wireless devices communicate with the computer through infrared or radio computer through infrared or radio waves.waves.

KEYBOARDKEYBOARD

PRINTERPRINTER

STORAGE DEVICESSTORAGE DEVICES