IGCSE - ICT - Chapter 2

Manual input devices

Keyboards, pointing devices, cameras, scanners, printers

Direct input devices

MICR, OMR, OCR, Magnetic strip reader, Chip reader, Bar-code reader

What are the type of sensors

Temperature sensors

Pressure sensors

Light sensors

Qwerty Keyboards

most common keyboard, standard english layout

Concept Keyboards

A keyboard in which the letters and numbers are replaced with pictures, symbols, or words that represent the concepts being used or taught

Numeric Keyboards

These are keyboards that manually input numerical data, often found in atm machines

Mouse

Allows the user to move the pointer on the screen

Touchpad

A small, flat, rectangular pointing device that is sensitive to pressure and motion.

Tracker ball

An input device that allows a user to move a pointer by moving a ball which is fixed in a socket.

Joystick

vertical handle with programmable buttons that controls action.

Touchscreen

a display device which allows the user to interact with a computer by touching areas on the screen

Graphic tablet

A graphic tablet enables drawn images to be input (using a digital pen) and stored on a computer.

Light pen

A hand-held device shaped like a pen that has an electronic sensor for making selections on a computer screen

Digital cameras

electric input device that records and stores single photographs

Video cameras

are used to take a series of images that can be run together to produce the illusion of movement

Webcams

has no strong storage capacity, connected directly to the computers

Microphones

can allow a computer to convert sounds into data that it can handle

Remote control

used to operate equipment such as TV and stereo

OCR

optical character recognition

compares shape of each character

OMR

Optical mark recognition

find marks

MICR

magnetic ink character recognition

both human and computer readable

Bar code

short parallel lines contrasting black and white

Magnetic strip

often appears on credit cards, library cards, hotel room key

chip and pin reader

Input device which has now replaced magnetic strip readers for the reading of credit or debit card details. Rather than signing to verify you are the correct owner of the card, you have to enter a four-digit

PIN

Personal Identification Number

analogue data

Analog (or analogue) transmission is a transmission method of conveying voice, data, image, signal or video information using a continuous signal which varies in amplitude, phase, or some other property in proportion to that of a variable.

digital data

Is text, numbers, graphics, sound, and video that has been converted into discrete digits such as 0s and 1s.

Temperature sensors

read the temperatures of their surroundings

Pressure sensors

Measure the pressure of a load

Light sensors

Measures the light falling on them

CRT monitor

Cathode Ray Tube, type of computer monitor which uses an electron beam to create the picture by shooting the beam at dots of phosphor in a vacuum tube

TFT monitor

Thin Film Transistor. They are much flatter, and so take up less room than CRT monitors. They use liquid crystals to form the image. Their small size makes them extremely popular

Laser Printer

Electrostatic printer that focuses a laser beam to form images that are transferred to paper electrostatically

Inkjet printer

A printer in which the characters are formed by small sprays of ink onto the paper.

Dot matrix printer

A printer that creates characters and graphics by striking an inked ribbon with small wires called pins, generating a fine pattern of dots.

Plotter

form output by moving a pen across the surface of a piece of paper.

Speakers

An output device that allows you to hear voice, music, and other sounds from your computer.

Actuator

the device that turns the computer signals into movement