Understood Conveys

Now we know computer hardware part 6: encoding standards work as binary numbers. But these numbers are hard to remember, which is why we often use the hexadecimal number system, if for example it comes to manipulate data in the computer language for people. The conversion should not be on here, because it is enough to know that this system has 16 digits, namely 0 to 9 for just this digit in the decimal system and A16 to F16 for 1010 until 1510, where the A16 of just the 1010, etc.. So 4 bits correspond to a hex character almost, because with the 4 bits, you can represent 16 combinations in the binary system. What is still the question of how exactly the computer represents for now example texts, which can contain so much more character. The answer is simple: it encodes the characters with the binary system. A very old standard for this is the so-called ASCII standard (American standard code for information interchange), it is available in several versions. There are now many coding standards, with which we are but not to deal in detail.

The original ASCII encoding uses 7-bit encoding, which means that you can represent exactly 128 different characters. This includes not only the alphabet, but also special characters or unrepresentable characters, such as pressure on the enter etc. Because the Americans have now E.g. umlauts, ASCII for the Germans was not very suitable. Other languages have not managed with special characters in the 7-bit standard.

Therefore the standard was expanded later, namely on 8 bit, which corresponds to a byte. But also you not enough 256 different possibilities to accommodate Greek, Japanese, or other characters. So, they developed the Unicode encoding, so it could encode all characters that are known in the world. Unicode can use 8, 16, 24 or 32 bit, so what is equivalent to 1, 2, 3, or 4 bytes per character. Thus it is 221 Unicode possible maximum, to represent different characters so 2.097.15210. The rest of the theoretically 232 possible characters are lost due to encoding. Today’s programs, such as Office suites, mostly independently identify what encoding it is and properly represent texts. This is not the case, there is a setting to adjust the encoding often. The introduction to the basic knowledge ends with this article to understand the internals of a computer. In the next article I will arrive closer to the hardware. See also: computer hardware – understandable conveys – part 1: introduction to computer hardware – understandable conveys – part 2: the real innovations in computer hardware – understood conveys part 3: numbering systems computer hardware – understood conveys part 4: number systems 2 computer hardware – understood conveys part 5: binary numbers writes in his spare time the author Michael Sander also articles for sites such as E.g. unstig.