Computer Keyboard - Special Keys

We just learned about the Computer Keyboard - Function Keys.

Another bunch of keys on the computer keyboard are the Special Keys.

We know the keyboard has all of the letters of the alphabet on it, but it also has some special keys that aren't used to type letters or numbers.
These special keys can do things like delete letters, move around the place on the monitor where you are typing, scroll up and down, or even do special things like save or quit.
A lot of the special keys have to do with moving the "cursor".
The cursor is the place on the screen that you are currently working at.
Sometimes it looks like this: | and sometimes it is just something highlighted a different color.
You move around your cursor to type words in different places, or to choose different parts of a program on the screen.

On most keyboards these are the special keys and what they can do:

Esc - This key can either leave or stop a program.
Tab - Can either put a big [   ] space in between a sentence, or it can be used to make different choices in other programs or switch programs.
Backspace - This will get rid of one letter to the left of where you were typing.
Insert - This can turn on "type over" meaning typing new letters will take the place of old ones.
Home - This moves the cursor to the beginning of a text line.
Page Up/Down - This scrolls the window up or down.
Delete - This will get rid of one letter to the right of where you were typing, or it can be used to get rid of files or emails or other things the cursor is selecting.
Shift - If you hold down Shift and type, the letters will be ALL CAPITALS.
Caps Lock - This is like using Shift, but you don't have to hold it down for the letters to BE ALL CAPITALS.
Print Screen - This can take a screenshot of what your monitor looks like that you can save in another program.
Scroll Lock - Some programs use this to change the way they scroll up or down.
Pause/Break - Some programs use this to pause.
Num Lock - If your computer has a number pad, turning this on uses numbers, off uses whatever special options are there.
Ctrl - This is a key used with others to do special tasks.
These special tasks work with most programs: Ctrl+A = Select all, Ctrl+B = bold, Ctrl+C = Copy, Ctrl+F = Find, Ctrl+I = italics Ctrl+N = New, Ctrl+O = Open, Ctrl+P = Print, Ctrl+S = Save, Ctrl+U = underline, Ctrl+V = Paste, Ctrl+X = Cut, Ctrl+Z = Undo.
Alt - Use the menus at the top of the program, like Alt+F usually opens the File menu.
[Windows] - The key that looks like 4 boxes is the windows key that opens the menu for programs.
Arrows - Arrow keys help move the cursor around on the page.


(from: wikipedia - computer keyboard)


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Computer Keyboard - Function Keys

We just learned about the Computer Keyboard.

Another part of a computer is the Computer Keyboard - Function Keys.

If you look on the top row of the computer keyboard, you should see the function keys that look like F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12
Those are called the "Function Keys", and they can do special things on the computer.

Depending on if you are watching videos on the internet or checking your email, these function keys can do different things.
Some of the keys are the same for all computer programs, like the F1 key almost always opens up the Help, and F3 is usually to find things.
On some keyboards you have to hold down a "Fn" key in order to use the function key.
For those keybarods the function keys can have other jobs like changing the computer volume, the screen brightness, or turning off wifi.

The most used function keys are: F1 - Usually brings up a help message to try and show you what to do.
F2 - Edit, like if you want to change the name of a file on the computer.
F3 - Search for some text on a page or in a file.
F4 - If you hold down Ctrl and press F4 it will close a tab. If you hold down Alt and press F4 it will close a window.
F5 - Usually refreshes what you are looking at, so if you have your email open it might check for new mail.
F10 - If you hold down shift and press F10 it will act like a mouse right-click
F11 - Switch to full screen mode

The other function keys are usually different for each program.


(from: wikipedia - function key)


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Computer Keyboard

We just learned about the Video Cable and the way a computer monitor works.

Another part of the computer is the Keyboard.

Before there were computers, people used to use typewriters to put letters on paper with ink.
When computers were made for people to put letters on the computer monitor, people made electronic keyboards that looked like the typewriters.
On a computer keyboard, when you press down on a key there it pushes down on a button that sends an electrical message to the computer telling you which key was pressed.
It's almost like your keyboard is made up of hundreds of little light switches and when you press one it turns a light on.

Most computers these days have letters in the "QWERTY" order, meaning that the letters are set up in the order where the letters are like:
1234567890
QWERTYUIOP
ASDFGHJKL
ZXCVBNM

The QWERTY keyboard style was invented back in 1874 when someone came up with the idea to put the letters in that order.
There are a lot of stories saying that it was to make sure typewriter machines didn't jam up, or to make people type faster, but nobody is really sure exactly why the computer keyboard doesn't go in alphabeitcal ABC order.

Other people have come up with keyboards that help people type faster, but because people had already learned how to type on QWERTY keyboards they have never changed.


(from: wikipedia - computer keyboard)


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Video Cable

We just learned about the Display - Refresh Rate.

Another part of the monitor is the Video Cable, or display cable.

This is one of the wires that comes out of the back of the monitor and goes to the computer.
The cable will send messages from the computer to the monitor to tell it what pictures to show on the screen.
If the computer is a laptop, then the monitor is connected right to the computer and it won't have a video cable outside the laptop.

Through the years since the monitors have gotten better at showing picturs, the cables have had to changes so they could keep up with the better pictures.

One of the first cables that was very popular was called the VGA cable, where VGA means Video Graphics Array.
This cable had 15 wires in it that the computer used to send the pictures that would go on the monitor.

Later on people wanted to make better pictures with the monitors so they came up with better cabels that could send more information faster to the monitor.
There are a few different types right now that people can get, but one of the most popular is called HDMI, which means High-Definition Multimedia Interface.
HDMI cables can come in different sizes like standard, mini and micro.


(from: wikipedia - vga connector)

(from: wikipedia - hdmi)


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Display Refresh Rate

We just learned about the Display Resolution.

Another part of a computer monitor is the Display Refresh Rate.

When the computer screen is playing a video, or opening up a web page or showing something on the screen, it has to re-draw the screen for that picture very fast so that your eyes don't notice that it is changing, and so that it just looks like a real picture.

In old computers, the screen was drawn fresh every time starting from the top left, and going row by row from the top to the bottom.
Newer computers with LCD and LED monitors have smarter ways to redraw just some parts of the screen, but they still can only "refresh" the image on the page at a certain speed.

The speed that the screen can change and show a new image is called the Refresh Rate.
Our human eyes can only really tell if something is flickering if it is changing less than about 60 times per second.
If you think of that like a paper flip book showing an animation, you can usually see the flicker for those.
But if they were flipping so fast you couldn't tell, it would just look like an animated cartoon.

60 times per second is called the frequency, and is also the same as saying 60 Hertz or 60 Hz because Hertz means "per second".
Most monitors these days have a refresh rate of at least 60 Hz.


(from: wikipedia - refresh rate)


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Display Resolution

We just learned about the Pixel.

Another part of how a monitor works is the Display Resolution.

We learned that a pixel is a picture element that helps draw a picture on the computer screen.
When you are looking at the computer, the picture will look more like a real life image depending on the pixel size, monitor size, and colors you can use.

If you have a normal sized computer monitor but you can only fit 100 pixels across and 100 pixels down, that makes for 10,000 pixels.
That seems like a lot, but computers these days usually show anything from 480,000 pixels on one screen to over 2 million pixels on one screen!
You can have the same size monitor but switch between low resolution (bigger pixels) and high resolution (small pixels) to fit in as many as you can on the screen.

In the first computers, colors were really only white or black, or sometimes green or black.
Some of the first computers made just for video games like the Atari could use 256 colors.
That might seem like a lot, but the computers today can use about 16 million different colors!


(from: wikipedia - display resolution)


(from: wikipedia - list of video game console palettes)

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Pixel

We just learned about the Computer Monitor.

Another part of a computer monitor is a Pixel.

The picture that you see on a computer monitor is made up of thousands or millions of little dots that can change color to show different pictures.
Each one of these tiny dots is called a pixel, which is short for "picture element".

On some old computers monitors, the pixels were big and looked like little squares or blocks used to make pictures.
Now the pixels are so tiny they can show pictures on computer monitors showing people and places that look just like the real thing.


(from: wikipedia - pixel)


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Computer Monitor

Let's learn some more about Computers!

One part of a computer is the Computer Monitor.

This is the part of the computer that you look at, that shows all of the pictures and videos that your computer puts on it.
Through the years computer monitors have changed a lot.
Long ago they only had a black background with white or green text.
Then later monitors could display every color, and also draw pictures on the screen for things like video games or office work.

For a long time, computer monitors were very big, using what were called Cathode Ray Tubes or CRTs to show things on the monitor.
They were later replaced by flat screen monitors, usually called Liquid Crystal Displays or LCD.
LCDs are much thinner, lighter, and usually taller and wider than the old CRT displays.
Some old CRTs could weigh 50 pounds, compared to an LCD with the same screen size weighing only 10 pounds.
Because flat screen monitors could be made so thin and light, people could make computers so small they could fit on your lap, called laptops!



(from: wikipedia - computer monitor)


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Computers

We just learned about the Tire Code.

We've learned a whole lot about car engines work!

Let's learn a little about Computers.

When we think of computers, some people think of the laptop they use at home, or the bigger computer they use at work.
Other people might think of the really big computers sitting alone in rooms at buildings doing gigantic amounts of work for hundreds, thousands or even millions of people.

There are other things that are computers that people don't really call computers, like tablets or iPads, cell phones, or video game systems.
All of these things have computers inside them that make them work.
These days even things like cars, airplanes, TVs, and even things like Washers and Dryers have tiny computers in them!

The first computers made were made over 50 years ago and filled up entire rooms with all of their parts.
Things have gotten so small now that a computer the size of your fingernail could do more than that whole room of computers did.


(from: wikipedia - computer)


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Tire Code

We just learned about the Tire Valve Stem.

Another part of a tire is the Tire Code.

If you look on the side of a car tire, you will see some letters and numbers printed on it.
These are there to help tell you what kind of tire you have, and also helpful things like how much air you should put into it.

Most tires use something called the "ISO Metric tire code" which has rules for what letters and numbers go in what order.

This code has these rules:

Use: One letter to tell how the tire will be used, like "P" for Passenger car, or T for a Temporary spare tire.
Width: Numbers for the width of the tire in millimiters.
/ in between the numbers
Height: Numbers for how tall the rubber part of the tire is. This is also called aspect ratio or profile.
Type of tire: One letter tells the type of tire, like R for a radial tire.
Rim width: The diameter of the metal rim that the tire is wrapped around.
Load: A code that tells how much weight the tire can take.
Speed ratimg: A code that tells how fast a tire can go.

So if a tire code says: P215/65R15 95H
That means it is a Passenger car, 215 milimeters wide, 65 millimeters profile height, Radial tire, 15 inch rims.
If you look up the 95H code, that means it can handle 1,520 pounds and go 130 miles per hour.


(from: wikipedia - tire code)


Kid Facts - Blast from the past: Smokebox

Tire Tread

We just learned a little about Car Tire.

One part of the tire is the Tire Tread.

This is the rubber on the outside of the tire that is in different shapes and patterns.
When there are lines in the tires, those are supposed to help the tire push water out of the way so the car doesn't slide around on the road.
Some tires made for the snow have bigger gaps in the tire treads so the snow can pack in there, and sometimes they even have hard bumps on the outside to help keep the car from slipping.
Tires that are used for racing are called racing slicks, and they have no marks on the tread at all.

After driving for a while, the rubber tread on the outside of the tire will wear out, and the tread will get smooth.
When this happens the tires need to be replaced.



(from: wikipedia - tire tread)


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Car Tire

We just learned about the Brake Pad.

Another part of a car is the Tire.

We know these are the things on the car that touch the road and spin around and make the car go.
Even though tires seem really simple, there is a lot of work that goes into making a tire that doesn't pop or slip all over, and that makes a car ride feel smooth.

When people first started making carts to sit in and be pulled by horses, they were mostly just made of wood, metal and leather so they were a very bumpy ride.
Now cars use rubber tires, that are smooth or bumpy on the outside depending on if you are driving in snow or on a race track.
There are even giant rubber tires that are made with no air in them so they can't pop.


(from: wikipedia - tire)


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Brake Pad

We just learned about the Brake Caliper.

Another part of a car is the Brake Pad.

Remmeber we learned that the caliper is wrapped around the spinning rotor and clamps down to stop it from spinning and slow the car down.
The brake pad is inside the caliper, and pushes against the rotor.
The pads scrape against the rotor, and eventually they will wear down and have to be replaced.
Cars have brake pads for their front wheels, and the back wheel pads are called brake shoes.



(from: wikipedia - brake pad)


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Brake Caliper

We just learned about the Rotor.

Another part of a car is the Brake Caliper.

We know the rotor is a disc shaped part inside the wheel that is spinning around.
The caliper goes on the outside of the rotor, and when you hit the brakes it pushes onto the rotor to stop it from spinning around.


(from: wikipedia - disc brake)


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Rotor

We just learned about the Lug Nut.

Another part of a car is the Rotor, also called the disc.

When the car needs to stop, the rotor is a disc shaped part of the wheel that is spinning around, and the car has brakes that clamp down hard onto the rotors to make it stop spinning and the car slows down and stops.


(from: wikipedia - disc brake)


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Lug Nut

We just learned about the Rims.

Another part of a car is the Lug Nut or wheel nut.

The lug nuts are what hold the rims onto the car.
If you need to replace a tire or work on the car brakes or the axle, you start by lifting up your car with something called a jack, and then removing the lug nuts using a tool called a lug nut.



(from: wikipedia - lug nut)


(from: wikipedia - lug nut)


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Rims

We just learned about the Cooling Fan.

Another part of a car is the Rims.

The wheels that the car rides on have big metal insides that are connected to the axle that spins around and moves the wheels.

These big metal cylinders are called rims, and they are made out of strong metals that can hold the weight of the car.
The tires are on the outside of the rims, for the rubber part that touches the road.



(from: wikipedia - alloy wheel)


Kid Facts - Blast from the past: Tender

Cooling Fan

We just learned about the car's Radiator.

Another part of a car is the Cooling Fan.

We know the radiator gets hot and has to get cooled down so it can put cold liquid back into the engine.
Most engines have a fan that blows air onto the radiator to help cool it.


(from: wikipedia - fan (machine))


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Radiator

We just learned about the Car Battery.

Another part of a car is the Radiator.

We learned before about the coolant passages in an engine that bring cooled liquid through holes in the hot engine to cool it down.

After the liquid called coolant comes out of the engine it has been heated up by the engine.
The hot liquid then goes to the radiator to get cooled off.
The radiator is a bunch of tubes with a bunch of metal fins on it.
The metal fins help pull the heat away from the tubes and cool down the liquid.
There is also a fan that is blowing on the radiator to try and cool it down.

The liquid that is in the radiator is called coolant or antifreeze, which is a mix of water and some other chemicals that won't turn to ice in the winter.




(from: wikipedia - radiator)


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Car Battery

We just learned about the Manual Transmission.

Another part of a car is the Car Battery.

This is a rechargable battery in the car that helps start the car and run other electrical things in the car like lights and radios.

When the car is running, the alternator charges up the battery.

Sometimes a car battery can run out of power.
This can happen if the alternator isn't working, or if someone leaves a light on in the car and the battery all gets used up.

If this happens, the battery has two metal posts on it called terminals.
You can hook those terminals up to another car's battery, and use that electricity to recharge your battery.


(from: wikipedia - automotive battery)


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