Thursday, October 14, 2010

My Favourite Storage Device and Media

Reasons for storing data are:
§  Basic setup information and operating systems are required for the computer to function
§  Application software needs to be available for the user to carry out tasks
§  Files created by the user need to be stored so that they can be used again
§  Data may need to be transferred from one device to another
§  Backup copies need to be taken in case the original files are lost or have become corrupt
MAGNETIC storage
§  Hard disks
§  Floppy disks
§  DAT tapes

OPTICAL storage
§  CD RW
§  DVD RW
§  CD R
§  DVD R

FLASH memory is usually used in portable devices like digital cameras, MP3 players, mobile phones and sat-navs

ONLINE storage – some photograph printing companies offer sites where users can store their photographs

My Favourite Output Device and Media

The main output device is VISUAL OUTPUT.
Screen/monitor
A screen or monitor can display both moving and static images. When choosing a monitor it is helpful to look at the resolution and size of the screen. The higher the resolution the more detailed the images will be. Images have pixels and the more pixels an image has the better quality that image is. CRT monitors were the main type of monitor a long time ago they used cathode ray tubes to transmit the images. In the modern day we use TFT monitors which are a lot thinner and take up less space however their image is not as clear as the image on a CRT monitor. Other types of screen you can have are:
digital projectors
interactive whiteboard
plasma screens
mobile phone screens/PDAs
Printers
There are many types of printers available today
·         Laser printer, works like a photocopier
·         Inkjet printers- cheaper than laser printers but not as good quality
·         Multi function printers, these include fax and scanner and are useful for office work or small businesses
·         Dot matrix printers, these are the quickest printer
·         Plotters
·         Professional printers
·         Photo printing
Speakers
SPECIAL PURPOSE OUTPUT DEVICES.
·         Larger monitor
·         Using sound rather than visual output
·         Braille printers

My favourite output device is the speakers as it allows you to listen to music as you work.

My Favourite Input Device and Media

The main data types are:
·         Text
·         Still and moving images
·         Numbers
·         Sound
We use data input devices to input all these types of data.
Keyboard.
This is the most common input device, it is used to input text. The most common type of keyboard is the QWERTY however there are variations of this layout in different countries and some keyboards have extra keys such as a numeric pad. Ergonomic keyboards have been designed to try to reduce RSI but people used to the standard type maybe reluctant to switch to one of a different shape.
Mouse
A mouse is used to point and select icons on the screen so it is another very important input device. There are variations of the common mouse. You can have a cabled one or a wireless. A mouse can either be optical or mechanical. Trackballs, trackpads and trackpoints can also be used in the same way.
Touch screens- respond to touch for data input
                        -senses when an area of the sreen is touched either by wires embedded in the screen or by patterns of infra-red beams
                        -PDA’s often use touch screens and can have a keypad, stylus and even handwriting recognition
Concept keyboard- divided into areas labelled to suit the actual use. Special software then interprets the key press for the computer. e.g. used in restaurants
Graphics tablet- used mainly for drawing, stylus is used to draw a bit like a pen on paper
Also a bit like an interactive whiteboard
Speech recognition- this involves theuser speaking into a microphone the sounds are converted into words. Not very widely available as certain accents can confuse words.
Automated input- some input devices read data from media that have the data stored on them.
Card readers- magnetic strip cards are swiped through a card reader. Easy to read. Not very much space. Can scratch easily.
-a smart card such as chip and pin has a computer chip built in. Can hold lots of data. Authorised by pin number not signature (no forgings) data can also be encrypted on a chip which improves security.
Radio frequency ID- uses radio waves to transmit a unique serial number as a form of ID or objects.
Scanners- turns paper based documents into digital images. A beam of light passes across the page and senses the colour of various areas. There are various types of scanner:
Ø  Flat bed
Ø  Bar code
Ø  Hand held
Ø  Drum scanners
OMR (Optical mark reader/recognition) AND OCR (Optical character reader/recognition)!
Bar code reader reads a barcode at EPOS and looks up the number in a database.
MICR (Magnetic Ink Character Reader/recognition) is used to read the magnetic ink (usually on cheques)
Sound input – analogue signal. Change to digital signal.
Video input – a video picture is made up of many still pictures played very rapidly to trick the eye into thinking it is moving continuously.
Webcams- small video cameras often used for video conferring
Digital camera- record digital images of the scene being photographed,
Special input devices (for people with disabilities):
·         The pointer speed of the mouse can be adjusted to make positioning easier.
·         The speed of mouse clicks can be adjusted
·         The buttons on a mouse can be set fro left or right handed use
·         The numeric keypad can be set to move the pointer in place of a mouse
·         A large trackball may make moving the pointer easier for a user with limited mobility
·         Single keystrokes can be set to replace combined ones like Ctrl Alt Del
·         Concept keyboards van be used to simplify the interface by restricting the number of input options
Games controllers – fast response, making the experience feel real, -----------WII
 Of all these input devices my favourite would have to be the digital camera as it allows you to enjoy memories again and again.