Input Devices Manual and Automatic By Laura and Gracie

Manual

Keyboard Used to input data into the computer Advantage They are very common; all computers have one and they are easy to use. Disadvantage Easy to make mistakes if you can’t type quickly. Concept Keyboard A pictorial keyboard which you can press. Advantage Easy to use and waterproof Disadvantage The screen can get dirty. Might need to change the pictures if your stock changes

Mouse Enables you to control the movement of the on screen curser by moving it around a surface Advantage Easy to learn to use Accurate for selecting things Disadvantage Need a flat space next to the computer. Tracker Ball Like an upside down mouse, you turn it with your hand to move the pointer on the screen Advantage Ideal for using when flat space next to computer is limited Disadvantage Not supplied as standard.

Joystick Similar to a tracker ball in operation except you have a stick which is moved rather than a rolling ball. Advantage Immediate feel of direction. Disadvantage Some people find them more difficult to use than mice. Microphone Used to input sound Advantages Some systems can understand most peoples voices with voice recognition software Disadvantages Some systems need to be trained to understand each different voice.

Digital Camera Looks very similar to a traditional camera. However, unlike photographic cameras, digital cameras do not use film Advantage No film needed. Images can be digitally manipulated Disadvantage Need to print out photographs Scanner Another way in which we can capture still images or text to be stored and used on a computer. Advantage Can input things from paper documents With OCR software, text can be scanned in Disadvantage Images can take up a lot of memory space.

Graphics tablet Produces much more accurate drawings on the screen than a mouse or a pointing device could. Advantage Effective method of creating or changing diagrams and images. Disadvantage Only useful for inputting data about diagrams. Can be very sensitive to movement and difficult to get used to using

Automati c

MICR Stands for Magnetic Ink Character Recognition. Banks use them; the reader reads the numbers on a cheque. Advantage Read at 100% accuracy.. Disadvantage The reader and ink is expensive OMR Stands for Optical Mark Reader. Reads pencil marks on a specially designed form or document, e.g. on a lottery ticket. Advantage Fast and accurate way of inputting information. Disadvantage Only works if the marks have been made accurately and clearly.

OCR Stands for Optical Character Recognition. It enables the computer to identify written or printed characters which have been scanned in. Advantage 95% accurate Disadvantage Needs careful checking as letters can be misread. Barcode Reader A bar code reader uses a visible red light to scan and read the barcode. The reflected light is translated into digital data that is interpreted by the computer and the correct price and product information is displayed. Advantage Any price change only needs to be changed on the computer system, not on each item.

Magnetic Stripe Build into back of plastic cards, e.g. identity cards or credit cards. Holds information about the card owner. Advantage Simple to use and cheap to produce. Disadvantage Limited storage capacity – only 60 characters. Sensors Sensors are used to detect physical quantities outside a computer such as temperature, pressure and light. To be able to process input from sensors a device called an analogue to digital converter must be connected between the computer and the sensors. This device converts signals from sensors into digital data that the computer can process