Computer System Hardware Alyssa

Computer System Hardware Output and Storage of the Computer

Objectives

To learn the most commonly used input devices

To learn and know the most commonly used output devices.

Identify and storage devices. Identify and describe how input and

output devices are connected to the computer.

Input and Output Devices

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

Output devices enabled the computer to give or show your results of its processing.

Some devices can perform both input and output operations.

Input Devices: Keyboard The Keyboard is the

most widely used input device.

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

Keyboard are divided into two sections.

Cont. Keyboard A keyboard is a human interface device

which is represented as a set of buttons. Each button, or key, can be used to either input a linguistic character to a computer, or to call upon a particular function of the computer. Traditional keyboards use spring-based buttons, though newer variations employ virtual keys, or even projected keyboards.

Input Devices: The Keyboard (cont)

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

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

Numeric keypad: Used in mathematical operations

Directional keys: Used to move the cursor around the screen.

Input Devices: The Mouse The Mouse is a pointing device

that rolls around on a flat surface and controls the location of the pointer on the screen.

The mouse performs the following functions:

Pointing: Placing the on-screen pointer at a specific place

Clicking: Pressing and releasing the mouse button.

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

Input Devices: The Mouse Mouse Functions (cont.)

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

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

Right Clicking: Pressing the right mouse button

Other pointing devices Other pointing devices that control the

on-screen pointer:

Trackball: This is like a mouse turned upside down. You roll a ball around with your finger to control the location of the pointer.

- These frequently are found on the notebook computers.

Other Pointing Devices (cont.)

Joystick and wheel – Joysticks consists of a metal and plastic handle mounted on a base that you can move in any directions to move the pointer or other object.

- These are typically used in video games such as Nintendo Wii.

- Most buttons that can be pushed or clicked to control output/input.

Cont. Other Pointing Devices

Other Input Devices

Pointing stick: A pointing device first developed by IBM for its notebook computers that consists of a miniature joystick, usually with a rubber eraser-head tip, positioned somewhere between the keys on the keyboard. Most pointing sticks are pressure-sensitive, so the pointer moves faster when more pressure is applied.

Cont. Graphic Table –is a computer input

device that allows one to hand-draw images and graphics, similar to the way one draws images with a pencil and paper. These tablets may also be used to capture data or handwritten signatures.

- This is commonly used by the graphic artists we had today like the artists from cartoon movies.

Touch Display – Screens that contain pictures or shapes that the user can press to input that data.

Stylus/digital pen –Used in mobile devices in input data

Touchpad – Used mostly in laptop/notebook computers

Audio/voice input – Inputting sound and/or voice

- These usually require a microphone or a special voice recognition software to be installed on the computer.

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

Image scanners for scanning images and text

Bar code scanners to read product bar codes

Magnetic scanners to read the magnetic strip on a credit card

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

the computer. Video Input: Input camcorder or VCR

using video capture cards

Biometric Input: Uses fingerprint, face, handwriting, and voice for identification.

Magnetic Storage Devices Floppy Disks: Small, portable disks that

hold a limited amount of data Hard Disks: Large-capacity and fast-

access storage devices. Zip Disks: Auxiliary storage devices that

can hold large quantities of data and can be portable.

Magnetic Tape drives: Used for making system backups and storing large quantities of data.

Optical Storage Devices

CD-DA: Audio CD CD-R: This drive allows you to read

and to write to a compact disk CD-ROM: Can hold large amounts of

data, but is read-only access

CD-RW: Can be written on several times

DVD-ROM: Read-only DVD format DVD-R: Similar to CD, but holds more

data; read only DVD-RW: Can be written on several

times Photo-CD: Used for storing digital

photographs on a CD.

Solid State Storage Media Non-volatile removable media Miniature mobile media - Uses Integrated Circuits USB flash drive

Caring for Storage Media

To safeguard your data from damage, follow these tips when dealing with removable media:

Keep away from magnetic fields Avoid extreme temperatures. Never try to disassemble the case. Remove media from drive when not

being used.

Tips for dealing with storage media (cont.)

- Write-protect important data. - Hold optical disks at their edges. - Never remove the media from the

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

transporting them.

Output Devices—Monitors

Monitors are used to display video output to a user.

Monitors may be monochromatic or color.

- Monochromatic monitors display output in a single-color display.

Factors that influence the quality of a monitor

-Screen Size: The diagonal measurement in inches of the display area

- Resolution: The number of pixels that that can be displayed in the displayed area.- Dot Pitch: The distance between each pixel in the display area.

Output Devices—Printers

Printers are used to create a hardcopy of a document or image.

- Printers vary by speed, quality, and price.

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

same techniques as copier machines Ink jet: Use fine nozzles to spray ink

onto the page as the paper passes through

Dot matrix: Work similarly to a typewriter in that ink is transferred to the paper by some part of the printer striking a ribbon to transfer an image

Laser Printer

Ink Jet Printer

Other Types of Output Devices

Speakers and headsets Fax machines and fax modems Multifunctional devices

Contain a variation of output options

Data projectors

Connecting I/O Devices to the Computer

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

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

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

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

Thank you!!!