Ordinary Camera O Pictures example essay topic

WIMP - Windows icons menus pointer (Windows icon mouse pull down menu) it was used early in the 1990's. GUI (Graphics User Interface) How a mouse works - the mouse uses a ball under it which can move north, south, east and west. As the axis pulses are sent to the computer. Mouse o A mouse is a pointing device which is the second most common input device. o A flat surface is needed for the mouse to function properly. o A small ball moves and the movements are detected by the way the ball was turning. o A small arrow moves around the screen using a special 'mouse driver'. This shows the mouse cursor on the screen. o A mouse has at least 2 buttons. A left button and a right button.

The left button is normally used to make selections. The right one is used for Pop down Menus, which change according to the application being used. o Touch pads and trackballs are two more pointing devices. They are used instead of a mouse. Advantages and Disadvantages o Allows different data to be put and point of the page. o Good for selecting items from menus. o Small o Difficult co-ordinations at first. o Needs a flat space. o Dust interferes with use. Joysticks o The joystick is usually used for computer games and controlling the way something moves. o There are 3 movements, up and down or side to side and diagonally. A jump or a gun can be activated by the button which is usually on the joystick.

Advantages and Disadvantages o Better simulation. o Specialized used. o Limited use. Touch Screens o When you touch anywhere on the screen it will be detected. o There are many different ways this can be done: o Infra-Red light shines from the top of the screen to the bottom and from side to side. The screen is divided into a grid and which ever part of the screen you touch the action will happen in. o Touch Screens can also be used in restaurants or fast food chains because it's easier than using a whole computer to input data. Only selected items are on the screens which are particular to the specific job. Digital Cameras o A digital camera can store a lot more pictures than an ordinary camera. o Pictures are stored in the floppy-disks or memory cards and can be transferred to the computer. o Light passes through the lenses. This is how the picture is taken. o A grid of light sensors is involved. o Different binary patterns are used to decide the colours of the picture. o Pictures can be easily saved and changed and edited on the computer. o Some digital cameras also have film o They are quite expensive.

Advantages and Disadvantages o No need to scan pictures. o No development time or cost. o Images can be easily edited. o Resolution not as good as an ordinary camera. o Can be expensive - up till $1000. Scanner o A scanner is used to transfer pictures and text in to a computer. o There are two types of scanners, hand held and flat bed. o Scanners work when beams of light pass over an image. o Different amounts of light refer to the picture. The data is used to produce a digital image of the picture that the computer displays on the screen. o The data is saved and can be changed. o You can covert the digital image of text into the text on the screen. Advantages and Disadvantages o Saves people having to hand draw images to illustrate typed text. o Scanned images are more accurate than clip-art. o Difficult to learn how to use. o Some images can take up a lot of space. o Used to be difficult to connect and takes up a lot of space.