cs100 lec 3 (hardware input & output )

8/8/2019 Cs100 Lec 3 (Hardware Input & Output )

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Hardware Components

Input Devices

Output Devices


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Input Devices - Consist devices that translate data into a

form the computer can process

Keyboard

is a device that converts letters, numbers, and other characters into electrical signals that can be read by the

computers processor.

2 types

1. Traditional computer keyboard (104 - 105 keys)

2. Specialty keyboards and terminals (touch tone

telephone keypads to keyboards featuring pictures of food

for use in fast-food restaurants


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TRADITIONAL KEYBOARD SPECIALTY KEYBOARD


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Pointing devices

Control the position of the cursor or pointer on the screen

1. mouse and its variants:

small, hand-held device is used to move the cursor to a specific location on the screen


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trackball a movable

ball, mounted on topof a stationary device,

that can be rotated

using your fingers or

palm


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pointing stick

looks like a pencileraser protruding

from the keyboard

between G, H, and B

keys


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touch pad a small,

flat surface over which you slide your

finger


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2. touch screen a video display screen that has been

sensitized to received input from the touch of a finger


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3. Pen Input:

Pen-based computer system

allows users to enter handwriting and mark onto acomputer screen by means ofa penlike stylus rather thantyping on a keyboard (ex.handheld and digital notebook)


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Light pen a light-sensitive

penlike device connected by a

wire to the computer terminal


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Digitizer uses a mouselike

copying device called a puck,

or an electronic pen, whichcan convert drawings and

photos to digital data. (ex.

digitizing tablet)


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Source Data-Entry Devices

Data are entered directly from the source. It creates machine-readable

data on magnetic media or paper or feed it directly into the computers

processor

1. Scanning devices.Scanners use light-

sensing equipment to

translate images of text,

drawings, photos, and

the like into digital forms.

a. Imaging System


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b. Bar-code reader


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c. Mark-recognition and Character-recognition devices.

c.1 Magnetic-ink character recognition (MICR)


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c.2 Optical-mark recognition (OMR)


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c.3Optical-character recognition (OCR)


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d. Fax machines

d.1 Dedicated fax machinesd.2 Fax modem


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Source Data-Entry Devices2. Webcam a camera that attaches to a computer to record moving images that can

then be posted on a website in real time


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3. Digital cameras electronic camera that uses a light-sensitive processor

chip to capture photographic images in digital form on a small diskette

inserted in the camera or on flash-memory chip.


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4. Human biology-input devices.

Characteristics and movements of

the human body, when interpreted by

sensors, optical scanners, voicerecognition, and other technologies,

can be form of input.

a. Biometric system.

b. Line of sight systems

VOICE

RECOGNITION

FINGER SCANNER

HAND SCANNER

EYE SCANNER


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Output Devices

Consists of devices that convert machine-readable

information, obtained as a result of processing, into people-readable form

2 types

1. Softcopy data that is shown on a display screen or is in audio

or voice form

2. Hardcopy printed output

Other Outputs


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Softcopy a. Display screen also called as monitors

2 Types

a.1 Cathode-Ray Tube (CRT)- is a vacuum tube used as a display

screen in a computer or video display terminal


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a.2 Flat-panel displaysare made up of two platesof glass separated by alayer of a substance inwhich light is manipulated(ex. Liquid crystal display(LCD)


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Hardcopy

a. Impact Printer- forms characters or images by striking a mechanism such as a printhammer or wheel against an inked ribbon. (ex. Dot matrix)


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b. Nonimpact Printers form characters and

images without direct physical contact

between the printing mechanism and

paper.

3 Types

b.1 Laser Printer


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b.2 Ink-jet Printer


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b.3 Bubble-jet Printer


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b.4 Thermal Printer


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c. Plotters.

3 Types

c.1 Pen


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c.2 Electrostatic


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c.3 Large-format


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d. Multifunction


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Other Output: Sound, Voice, and Video

1. Sound Output devices produce digitized sounds, ranging from beeps

and chirps to music. (ex. speaker)


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2. Voice Output Devices convert digital data into speech-like

sounds. (ex. in telephone answering machine, cars, toys and games)


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3. Video Output video consists of photographic images, which are playedat 15-29 frames per second to give the appearance of full motion.

cs100 lec 3 (hardware input & output )

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