Computer Mouse

We just learned about the Computer Keyboard Special Keys.

Another part of a computer is the Computer Mouse.

Just like the keyboard, this is part of what you use to tell the computer what you want to do.
It was called a mouse, because it looked like a little mouse with a tail, but lots of computer mice these days don't even have wires.

When you move the computer mouse around, there is a picture on the monitor usually shaped like an arrow called a cursor.
Computer mice usually have 2 buttons, and when you press the button it's called clicking.
If your mouse cursor is pointing at something like a button and you click the left button it will press the button on the screen.
The right button is usually to give you choices for things, like if you want to copy or paste some text just like you would from the keyboard.

Some mice have another spinning button called the scroll wheel that helps scroll things up or down on the monitor.


(from: wikipedia - computer mouse)


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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)


Kid Facts - Blast from the past: Boiler

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)


Kid Facts - Blast from the past: Firebox

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)


Kid Facts - Blast from the past: Piston Rod

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)

Kid Facts - Blast from the past: Coupling Rod

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)


Kid Facts - Blast from the past: Brake Shoe

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)


Kid Facts - Blast from the past: Trailing Wheel

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)


Kid Facts - Blast from the past: Smokebox

Binary

We just learned about And Or Logic Gates.

When we talk about letters and words, we know that A is a letter,
and Apple is a word with the letters A, p, p, l, e.

For numbers, instead of saying letters we call them digits So the number 174 has the digits 1, 7, 4.

The numbers we use every day go from 0 to 9.
The digits are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
(The number 10 uses the digits 1 and 0.)

Since there are ten digits, we use the word decimal.

What if we only had two digits to use, 0 and 1?

Could we still make numbers?
Yes!

We can make the numbers: 0, 1, 10, 11, 100, 101, 110, 111 and so on!
Since we're only using 2 digits, we use the word binary (like bicycle which has two wheels)

When we want to match up our decimal numbers to our binary numbers,
we just put them in the same order.

binary 0, 1, 10, 11 is the same as decimal 0, 1, 2, 3
So b0 = d0, b1 = d1, b2 = d10, b3 = d11 and so on!

We already learned about how computers use 1 and 0 to turn lights on and off on your computer screen.

The whole computer uses just binary numbers to do all the math to turn those switches on and off.

Just think, giving a computer a number like: 1110 can be like telling it to turn 3 lights on, and the other one off!

(from: wikipedia - binary number)

And Or logic gates

Last time we learned about true and false
and how they worked in computers like On and Off switches
turning thousands of light bulbs on and off.


(from: wikipedia - incandescent light bulb)

Now think about what would happen if you had two light switches
called switch A and switch B,
and they were hooked up to the same light bulb.


(from: wikipedia - light switch)

Would you have to have both switches set to ON for it to turn on?
Or is just one good enough?

In computers and electronics, we call that using AND and OR.
So if you need both light switches ON to turn on one light bulb,
that means you need A AND B on.

If the light will turn ON with either switch,
that means A OR B.

When people draw out the AND and OR in pictures,
they sometimes call them logic gates. There are different pictures for an AND gate and an OR gate.

The AND gate sort of looks like a big letter D.

(from: wikipedia - and gate)

The OR gate sort of looks like a spaceship!

(from: wikipedia - OR)

Using those logic gates like switches to turn on and off light bulbs,
you can draw up big pictures that can be used as instructions for building a computer!

(from: wikipedia - logic diagram)

Boolean True False

We just learned about the colors in ROY G BIV.

You probably already know this, but True is a way of saying Yes.
and False is the opposite and means No.

A fancy word for True and False is Boolean
named after the famous mathemetician George Boole.

In computers and electronics, it's kind of like you're looking at a light bulb.
If the light bulb is ON, you can call that True or Yes or even the number 1.
Is the light bulb is OFF, you can call it False or No or the number 0.

(from: wikipedia - light bulb)

Inside computers the electricity that runs the computer has thousands
or even millions of little ones and zeroes, meaning True and False.

These little light bulbs are what make the pictures on your computer screen
and the light switches come from things like your keyboard and mouse.

You can imagine a room just filled with light bulbs and light switches,
and that's exactly what some of the oldest computers (like the ENIAC) looked like!

(from: wikipedia - eniac)

USB

We just learned a little about Text Messages.

Let's learn about more fun stuff!

USB stands for Universal Serial Bus

It's the name of a type of connector for computers, to connect phones, computers, cameras, and just about anything else!

This is what a USB port looks like on a computer:



And this is what a USB cable looks like:

(from: wikipedia - usb)

Hardware & Software

For computers, the word hardware means all of the hard parts of the computer, like the screen, buttons, keyboards, all the bits and pieces inside a phone or laptop or desktop computer.


(From: Wikipedia - Personal Computer Hardware)

The word software means all of the things that the computers do, like games and programs that run and make the computer work.



(From: Wikipedia - Angry Birds)

ENIAC

We just learned about what an Electrical Box is.


The first computer was called the ENIAC.
(Sounds like Any-Ack) It stands for a bunch of big words that just mean it was a big math calculator:
Electronic Numerical Integrator And Computer


(From: Wikipedia - eniac)

It wasn't like any of the fancy computers we have now with big colored touch screens!
It was a whole room full of wires and lights and could only do math problems with numbers.
This might not seem like much, but it could figure out over 350 problems like this in less than a second.
Way faster than most humans!

9,292,532,154 x 2,135,484,354 = 19,844,057,023,908,918,516