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Computer
keyboards – how do they work? Have you ever wondered what
happens with a keyboard? How does the stuff you’re typing in magically appear
on the screen? Have a look at the keyboard on your PC. It doesn’t
really look that exciting does it? But, if you were to take it apart and look
inside it you’d find all sorts of things – but you’d better not
do it to the one you’re using right now because you might trash it and it
won’t work again! It might be a better idea to ask a computer repair shop
if they have an old one you could have a look at. So what
actually happens? Is there a tiny Harry Potter inside the keyboard waving a wand?
Or, are aliens watching from outer space who know exactly what you’re going
to do next? Actually, it’s not really that way out –
but it is kind of interesting. First of all every keyboard has a processor (not
a wand) inside it and its job is to translate what you’re typing on to the
keys into something your computer can interpret. Underneath
the keys that you type on is a thing called a key matrix. It looks a bit like
an aluminum oven tray with a load of dots on it. Only the dotty things aren’t
bits of baking, they’re actually tiny little things called circuits and there
is one for every key on the keyboard. When you’re not using a key the circuit
underneath doesn’t touch it; we say that the circuit is then open. But when
you do press down on a key, it then will then press down on the circuit below
it – and hey presto! The two things touching together make a current (it’s
a bit like when you flick down the light switch and the light goes on). This time
we say the circuit is closed. The processor inside the keyboard
checks all the time to see what’s going on with all the different circuits.
When it finds one that is pressed down (or closed) the processor then compares
the position of that particular circuit to one on a map that has already been
built into the computer’s memory. This built-in map is called a character
map. It’s a bit like when you look up a street name on the index of a map
to find the grid reference, e.g. J9 or F15, of the place you want to go –
the index and the actual map will match. So, the keyboard processor
checks out all the stuff you’re typing and then works out what information
(or data) it needs to send on to the computer. The information then travels through
a connector in a special computer language known as binary code. This information
then travels on to the computer’s operating system which translates the binary
code into words we can understand and makes whatever you’ve typed in appear
on the screen. So, lots of things have to happen every time
you press a key. All that checking of circuits, comparing it to what’s already
loaded into the computer’s memory and then the sending on of information
– it’s all so quick. There doesn’t seem to be any delay between
the time you type in something before it appears on the screen. Amazing, don’t
you reckon? Wouldn’t it be great if bedrooms got tidied
up that fast – or even homework – now that would be really cool!
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Let’s
see how ‘keyed up’ you really are. 1. What does every
keyboard have?
a) A wand
b) A processor
c) A connection 2.
What is under the keyboard?
a) Baking
b) A key matrix
c) A desk 3.
What does every key on the keyboard have?
a) A finger typing on it
b)
A circuit
c) A letter or number 4. What is the map in the
computer’s memory called?
a) What?
b) A character map
c) Helpful 5.
How does the information travel from the keyboard to the screen?
a) The aliens
take it
b) Through a connector
c) Almost instantaneously
Results:
If you answered mainly A’s Yes, indeed. The keyboard is
a mysterious object! Its secrets remain closed to many of us. You are not alone.
Never mind, the baking you did on the key matrix was quite inspiring. B’s
Wow! Your recall’s pretty impressive! You’ll be pulling apart jet engines
and performing rocket science before you know it. C’s
You’re creative and yet very practical aren’t you? Good things are coming
your way - but is there really writing on your space bar? [We’re referring
to the long one on your keyboard, not some intergalactic club.] Back
to Tech Frenz | |
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