|My Favourite: OUTPUT DEVICES

An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) to the outside world.

Monitor

The most common output device is the monitor or VDU.
Modern monitors, where the case isn’t more than a few centimetres deep, are usually Liquid Crystal Displays (LCD) or Thin Film Transistors (TFT) monitors.
Older monitors, where the case is likely to be around 30 cm deep, are Cathode Ray Tube (CRT) monitors.







PRINTERS

Common output formats are printed paper, saved files, sound, video and on-screen documents. They let the computer communicate with the user. Examples of devices that take advantages of these formats are:

*Laser printers are quite expensive to buy and run but produce a high quality output and are quiet and fast.




*Ink-jet printers offer black and white or colour printing with reduced levels of quality and speed. Colour ink jet printers are cheaper to buy than colour laser printers.




*Dot matrix printers are not so common today. They are comparatively noisy and low quality but are cheap to run and are used when carbon copies or duplicates need to be made, such as for wage slips. Also, they are useful in dirty environments such as a garage because they are much sturdier than the other two types of printer.





In my opinion, the screen is the best output device because it is the most useful, and computer cannot be used without it!




Other output devices include:
Speakers
Buzzers
Motors
Lights
Mecanical Devices.

Input devices allow us to enter raw data into a computer. The computer processes the data and then produces outputs that we can understand using an output device. Input devices can be manual or automatic. Input > Processing > Output. The processing is mainly handled by the Central Processing Unit (CPU).

The most common manual input devices are the mouse and keyboard. Here are some of my favourites:

Touch Screen: A touch sensitive visual display unit (VDU) or screen has a grid of light beams or fine wires criss-crossing the screen, that are used to detect touch. Many mobile phones use touch screens and do away with the keypad entirely. They're often used on tills in supermarkets and in other shops too. Touch screens are robust, easy to operate and easy to reprogram.

Barcode Readers: Barcodes are represented by black vertical bars and are read by a barcode reader. Barcodes are printed on nearly every product you buy, each product has a unique code. When read, information stored in the shop's database is recalled, such as the product name and price. This information later appears on the till and on your receipt. The scanning process also assists in stock management, reducing the stock by one each time a product is scanned/sold. This can help with stock levels and crime prevention.

Microphones: Used to input sound. In computing they can be used with voice recognition software and a word processing application to enter text. Webcams commonly have microphones built-in too like ones on a laptop.

Card Readers: Magnetic stripes are built into many plastic cards such as debit or credit cards and personal identity cards. The magnetic strip on the back of the card can hold the personal details of the card owner and, with the necessary PIN, will allow access to secure information, eg bank account details. Data stored on the strip is scanned and input into a computer system by a magnetic stripe reader.

Digital Cameras: A digital camera takes pictures and can usually record video too. The pictures it takes and the videos it records are stored in files. These files can be copied to a computer and later edited.

Joystick: Used to be popular with gamers but have slowly been replaced by other types of game controller. In construction, joysticks are used to control machinery such as cranes.

Games Controllers: Computer games often demand fast response times and manufactures make special controllers for them. Some games stimulate activities such as driving or flying. For example the Nintendo Wii.