Posted by admin on 22nd March 2010

Input Devices

Input devices are any way that you or another person can change what a computer is doing or input new data to it. They range from obvious things like a keyboard and mouse, through cameras and microphones to strange ones that you might never think of like MICR and chip-and-pin.

Manual Input Devices

These devices require direct human action to make them work – they include most of the obvious ones like mouse and keyboard. You may need to say why these would be the most appropriate input device, so think about what you can do with these devices and how quick it can be.

Other manual input devices like a graphics tablet allow you to do slightly different things – using a pen on the special tablet, you can draw much more accurately than a mouse would allow. A touchpad sounds almost the same, though what it really means is the little square you use on a laptop instead of a mouse. Why use it? Because it takes up less space, which is very important when we’re looking at portable devices. A touchscreen is found on some computers and on PDAs but more and more on phones. These are all called pointer devices because they move the little arrow on screen, the pointer.

You may have used a concept keyboard at primary school, but they’re also found attached to tills at shops – areas of the keyboard can be programmed to do different tasks and a new overlay sheet will allow you to do enter different information. This is a much quicker input than a standard keyboard if you have a very limited number of options to enter.

A microphone allows sound to be entered into the computer, for many different purposes, from recording a band to chatting to a friend to controlling programs.

Some different imaging devices fall into this category too, like webcams or other cameras and even scanners too. These all allow you to capture an image to enter into the computer. What you do with it then is up to you – chat to someone, edit the photo, or send it straight to the printer. A scanner allows you to place a sheet of paper on the glass plate, then like a photocopier, it moves across the paper, scanning in what it looks like to a computer.

Automatic Input Devices

These devices are ones you’ve maybe not really heard of and have weird names that are hard to remember. I find it helps to repeat them out loud as you read and even write them down as you look at the information.

You’ll be familiar with barcode readers, which are used in all kinds of shops to recognise items. They have a short code – the numbers on the barcode – that the bars allow the laser scanner to detect. This allows the till that the reader is connected to, to search for the item and display the price and other details. Chip and pin is another one you’ll have seen in shops – a microchip in the card (a smart card) is read and the pin compared to the data on the card. If it’s right and you have enough money available, you can buy the product. Before pin machines, credit and debit cards used magnetic stripes to hold information about the owner. These stripes are still used for cards, from hotel door keys to Tesco Clubcard. Again, a reader decodes the information to verify that you are the correct owner and then money can be transferred or the door opened!

On a cheque there are weird shaped letters printed on the bottom in a special magnetic ink. MICR stands for Magnetic Ink Character Recognition and banks use it to check that no one has tampered with the numbers to make a fraudulent cheque. Black pen won’t fool the reader because it’s not magnetic. MICR machines can quickly read the numbers on hundreds of cheques.

OCR is Optical Character Recognition – no fancy clever inks here, normal photos are analysed to see if letters can be made out. If so, the software will turn the photo into an editable file that you could open in your word processor – really handy if all you have is a printout of your work! OCR can be slow and unreliable – it can be confused between a capital “I”, the letter “l” and the number “1″ for example. Just a few mistakes can make it take a long time to get accurate scans of text.

Some tests can be automatically marked with an OMR, Optical Mark Reader. It can tell if you’ve coloured in the correct box and assign a mark accordingly, much quicker than a human marker. Obviously, it can’t mark essays, only multiple choice, so not really a good option for GCSE English Literature!

That’s a quick summary of input devices – quite a lot, isn’t there? See what else you can find out about input devices.

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