andreas.com FAQ: KeysFAQ: A Bit about Keys
The way in which keys and computers work to produce alphabets is somewhat interesting. Let’s take a look at the process by which we turn a spoken language into something which can be used on a computer.
Sometimes, you’ll notice that odd symbols appear. Your friend typed a letter on her computer and on your screen, there are extra symbols, some characters are missing, or you print something and sometimes a character will be changed or different. You try to change your document into a new font but you get odd characters. Here’s why.
On a mechanical typewriter, you press the M key and a series of levers and pulleys slap a lever with a little M on it against the paper. On a computer, everything is electronic. This means that the character M is not the computer character M. Nothing with computers is that easy. In fact, there are no characters in a computer, aside from the ones which are painted on the top of the keys.
The American English spoken alphabet can be spelled with 26 letters. Other alphabets, such as German, have 30 characters. German has the additional characters ä, ö, ü, and ß.
A written alphabet, however, has more characters. The written English alphabet has 26 capital (or majuscule) characters and 26 small (or minuscule) characters for a total of 52 letters. For example, there is M and m. Not only do they look different, but they act differently. One is a capital letter and starts a sentence; the other is a small letter and is only found within a sentence. We also have punctuation marks, such as ?, !, and the space between words. We use these only in written English, not in spoken English. There are also our written symbols for numbers (1, 2, 3, etc.), which we borrowed from Arabs. (Numbers are also interesting. We have two numbering systems in English: Cardinal numbers (1, 2, 3…) and ordinal numbers (first, second, third.) Japanese have dozens of numbering systems, based on the quality of the thing being counted.) All in all, American English can be written with about 150 characters.
The collection of characters of a written language, or the character set, is special for each country. There is American English, British English, etc. An American computer will have to be able to deal with a few odd symbols (such as #, $, and @). British don’t have the # symbol; in fact, they don’t know what it is. Their keyboard has a £ symbol, which doesn’t exist on an American keyboard.
Furthermore, written alphabets have different looks. By changing the font, the words look different. A font family, such as Arial, is made up of Regular, Italic, Black, and so on. There are thousands of fonts.
All of this has slowly evolved with mankind’s discovery of writing and the various tools of writing. The earliest writing tool was a wooden stylus and tablets of clay. The Romans invented the feather quill, which was used until the 19th Century. Law offices had a boy who took care of the office’s flock of geese. Every morning, he’d collect feathers and, with his little knife, called a pen knife because it was used to cut pens, he’d make the quills for the day. An Englishman invented the steel writing nib, which threw geese into unemployment. In the early part of this century, the typewriter was invented. The steel nib was replaced by the fountain pen, which in turn was replaced by the ball-point pen in the 1950s. The word processor was invented in the ’60s and became wide spread in the ’80s. As writing became computerized, worldwide standards had to be developed. This is done in the following way.
As we know, computers use electronic pulses of high or low flows of electricity. We use binary notation to assign 1 or 0 (null) to those electronic states. Each number is called a bit. By using eight binary numbers or bits, we can assign a number to each character of the American alphabet.
That number is called the key scan code number. For example, small m is number 37. When you press m, the keyboard’s chip tells the computer that key 37 was pressed. The computer has a chip that holds the ASCII Table. The computer looks up the key 37 in the ASCII table and finds the numeric value for that key, which is a binary number of eight bits and may look like 00100101. This binary numeric value isn’t an M. It’s only a number value for that character.
To create a written character on your screen or on your printer, the computer then has to see which font you have assigned to the character set. In the slot for 00100101, there can be anything that one can draw within a grid: this could be a drawing of an M or an m. Depending on the font, this can look different, such as M and M. If you’re using the Wingdings font set, it can also be a small airplane.
There is not much of a standard as to where the keys will be on the keyboard, or what drawing will be generated when you press that key. In the beginning of computers, each country had its own numbering system. The German ä had a different number than the Swedish ä.
IBM’s system, which is called the ASCII standard, allows for 256 characters and covers the American and European characters plus several typographer’s symbols. However, this wasn’t adopted systematically, and the same character may have different values in different countries. Not even DOS and Windows use the same system, even though both are from the same company.
Then there’s the rest of the world: Japanese, Amharic, etc. By doubling the IBM system, we arrive at the Unicode system, which permits some 65,000 characters. Unicode is gradually being included in computers and, in a few years, your computer will be able to write in any written language. Luckily, the number of written languages is much smaller than the number of spoken languages. Of some 3,500 spoken languages, only about 70 have a writing system.
All of this means that the characters aren’t fixed to your keyboard. You can put any character onto any key. You can use a keyboard editor, or reassignment program, to move the keys around or add new characters to your keyboard.
How Many Keyboards Do You Have?
This is a trick question. Keyboards use the same mode system that is so annoying with electronic wrist watches. If you press an electronic watch button, it turns on the light, but if you hold down another button and then press the same button, it shows the date.
- The small letters mode. Just press a b c to get a, b, c.
- The capital letters mode. Use this by holding down the Shift key and then pressing a b c to create A, B, C.
- The Control mode. Hold down the Ctrl key and press any letter. The result is a command code such as Ctrl+S which saves your work.
- The Alternate mode. Hold down Alt and press a key. This usually creates another command.
- The Caps Lock mode. Press it down and the keyboard types only capital letters. This has mostly the same result as the “Shift + any key” method; nevertheless it’s different, in that Caps Lock + 2 gives you 2, not @.
- The Escape mode. For DOS users, there are the Esc command combinations.
- Finally, there are multiple combination modes, such as Ctrl + Alt + any key or Ctrl + Shift, Alt + Shift or even Ctrl + Alt + Shift.
- And did I mention that the right Shift and the left Shift have different functions?
These combinations mean that we actually have some ten different keyboard modes.