# The Computer Revolution/Peripherals/Keyboards
## Keyboard function
### Typewriters

The earlier keyboards attached to the typewriter had its bugs to work out, many of the keys when typed too fast and would run into each other and get tangled up. To fix this they took the keys and rearranged them so people would type slower and less chance of the keys being mixed up. Then the QWERTY and DVORAK keyboard was born.

### QWERTY

Is designed to slow down the typer's speed. It spaces the keys out to slow down the average typing and is now the most common key board there is. C. L. Sholes is the inventor of the QWERTY keyboard.

### Context Keys

Context keys make other keys behave differently. For example, using the "ctrl" key or the "alt" key when using other keys.

### Function Keys

Used to call up a menu or perform a function, they are located in a cluster on the left side or in a row across the top of the keyboard (F1, F2, etc.). They are often used with the shift, control and alt keys to extend the number of options. Many programs extend the usefulness of the function keys by using key combinations. The most common combinations are Shift + a function key, Alt + a function key, and Crtl + a function key. These combinations can be very useful. For instance, in Microsoft Word, when any text is highlighted, pressing the Shift key plus the F3 key will change the case of the text from all caps, initial caps, to all lowercase. Shift + F7 will choose the Thesaurus command. These shortcuts allow you to access such functions with one keystroke rather than three or four mouse clicks.
F1-As a throwback to DOS days, you will find that the F1 key will often bring up a help menu. If you press F1 while working in a program, help for that program will usually appear. If you press F1 while at the Windows desktop or when the Windows Explorer is open, a Windows help screen will pop up. If you happen to be working in a program and would like to see the Windows help screen, simply press the Windows key (the key with the Windows logo on the bottom row of keys) on your keyboard and press F1 at the same time.
F2-You can use the F2 key to rename an item when working in Windows. Highlight any folder or file, and press F2. You will then be able to type a new name for the object. After you type the new name, just click outside the name box or press the enter key to make the name change. This works just like right-clicking a file or folder and selecting Rename.
F3-When you are working in Windows, the F3 key will open the Find Files window.
F4-The F4 key has some very useful functionality. You can press F4 to open the Address bar when working in Internet Explorer. This will allow you to type the address of a Web page for quick access. You can also press the Alt key and the F4 key at the same time to close the open Window that you are currently working on.
F5-The F5 key is the refresh key. You can press F5 when viewing a Web page to make sure that you have the most current version of that Web page. You can also use F5 when in Windows to refresh the screen. This can be a handy shortcut. If perhaps you are viewing the contents of a floppy disk and you insert a new floppy, your screen will still show the contents of the first floppy. Just press F5 to refresh the screen and see the contents of the floppy you just insert
F6-This key is often used to move the cursor around the structure of the program. Pressing it will often cycle you from window to window.
F7-The F7 key does not have any functionality in Windows. It may, however be used in some individual programs. To find out if it is available in the program you are using, bring up the program's help screen and type in the words function key.
F8-The F8 key can be used to access Safe Mode if pressed during the computer's boot up process. This is a trouble-shooting mode, which will start the computer with minimal drivers.
F9-The F9 key does not have any functionality in Windows. It may, however, be used in some individual programs. To find out if it is available in the program you are using, bring up the program's help screen and type in the words function key.
F10-This key is used to activate the menu bar in many programs. You can use F10 to highlight the first menu choice, and then use the arrow keys to move around the menus. Pressing the Shift key while pressing F10 will bring up the shortcut menu. This is similar to right-clicking on an object.
F11-Press F11 when you are working in Internet Explorer and the window will open to full screen mode. This will make all the toolbars disappear and can be useful to see more information on the screen. Press F11 when you are in full screen mode will toggle you back to your normal view.
F12-The F12 key does not have any functionality in Windows. It may, however be used in some individual programs. To find out if it is available in the program you are using, bring up the program's help screen and type in the words function key.

## Types of Keyboards
### Wired

The very basic and first keyboard was wired to the back of the computer. Current day keyboards are hooked up to a USB port or a PS2 port. In the beginning there was no USB or PS2 ports, so the keyboard had to hook up to a special keyboard connector port. Included in the wired keyboard and virtually every keyboard are the standard keys. There is all the letters of the alphabet, numbers zero through nine, a delete and backspace key and an alt and control key (for altering the function of another key). Some of the more sophisticated keyboards come with scroll wheels to make scrolling more efficient as well as special keys for different functions like the backlighting or volume control. For safety purposes, some keyboards come equipped with a biometric reader.

### Wireless

By having an infrared sensor hooked to your USB or PS2 ports, the keyboards with the infrared sensor can send messages to a receiver placed anywhere within the sensor's range. This is handy for those who need to move the keyboard away from the desk or the wire does not reach to the back of the computer. Now a days the keyboards use their own special sensors (radio or Bluetooth) so there are no mixed signals coming from other objects.
Besides having a wired keyboard which you are tied to the computer at all times you can enhance your experience by using a wireless keyboard. The advantages of a wireless keyboard include that you are not tied to the hard drive and can use it anywhere within the vicinity of the signal you are receiving from the sensor you connect to the computer. On the other hand the disadvantages are you are always changing the batteries on a weekly basis. Thank god they invented rechargeable batteries or you would spend a fortune every month for a pack of batteries.

### Foldable

Collapsible and easily folded up for easy travel. This is designed for the person on the go. They are designed specifically for PDAs.

### One Handed

Designed to have all keys in one hand, this key board makes it easy for people to type having all keys more accessible.

### Optical Virtual

The latest in keyboards, designed to project a image from a sensor onto a table. The light bounces off your fingertips and relays information back to the sensor on where your finger position is depending on where the keys are hitting. Optical Virtual keyboards have been around since 2008 thanks to the engineers at IBM. It has been noted that some of the optical keyboards primarily use a laser to detect finger tip movements, however, other optical keyboards use an infrared beam (invisible beam) as a secondary beam for more accurate results when typing. Optical keyboards can cost the consumer anywhere from 100 dollars up to several hundred.

### Ergonomic Type Keyboards

Ergonomic keyboards are designed specifically to provide the user with increased comfort and to minimize the risk for hand and wrist injuries. One of the best examples of a ergonomic styled keyboard is the split-key keyboard. These keyboards are designed with a "curved" key layout which is designed to fit the curve of a user's hand so that it has less strain on it and thereby minimizing injury. One of the best examples of an ergonomic keyboard is the split-key keyboard which separates the keyboard into 2 or more sections and allows the users hands and arms to be in a position that is more natural and more comfortable than the standard keyboard.

### Touch Screens Keyboards

Touch screens allow the user to touch the computer screen with their fingers to select commands or otherwise provide input to the computer associated with the touch screen. There are also multi-touch screens, they recognize input from more than one finger at a time, making it easier and faster to write. Touch screens are found on consumer kiosks, and mobile device up to commercial and other point of sale systems.

## Keyboard Switches
### Membrane

These switches use a continuous membrane with circuitry built directly into it. Pressing a key on the membrane completes the circuit. These types of switches generally provide no audible response and have poor tactile response.

### Mechanical

These switches are individual points of contact under each key. There are a variety of different mechanical switches, of which Cherry MX Black, Cherry MX Brown, and Cherry MX Blue are a few examples. The varying switches all have different attributes, examples being tactile response, audible response, force required to activate, and activation point.

### Rubber Dome

These switches are a combination of both the mechanical and membrane styles. In this style there are rubber domes built into a membrane with a conductive material in the center that is used to activate on key press. This type of switch generally has good tactile response and no audible response.