Last couple of years, because of work requirements, learned a hodgepodge of many languages, plus the usual look of books from the United States, just free to write an essay on entry-level computers.
Then I start talking about the network, I want to talk about the simple and clear, I understand at a glance. Since the expression of numbers are not very stable (error-prone), so the only computer in the real world in binary, decimal, sexagesimal other ways. Hex is a concept, such as between the hours and minutes are sexagesimal 30 minutes into hr is: 30 ÷ 60 = 0.5 hours; another example is between 24 hours and hex days, 8 hours into days, 8 is ÷ 24 = 0.33 days. Say this means that any one number can be used other hexadecimal, but can also convert between hexadecimal. Just decimal column is a special, easy to accept in accordance with the people's thinking habits. I will not talk about how to convert between binary and decimal, some people say it will be a headache (those who are interested, please cramming math), but you see a lot of talk about a long list of computer books will be similar to "10010011" in digital, which means that a number on it.
When the communication between the computer, but also based on a table (ASCII table), if in the English language, as long as can transmit 26 English letters, can communicate a. So I can simply analogy, such as setting yourself a table, a → 1, b → 2, c → 3, ...... and so on (decimal expression), at most, then the corresponding comma, full stop, space (assumed to be 27), you can use all over the world to communicate with the English. For example, I want to send a "I love you", the computer will transfer 9,27,12,15,22,5,27,25,15, 21, then the receiving side or in accordance with this table, the corresponding line expressed. Here Chinese characters on its hands, just 26 letters in English communication is enough, so many characters, so correspondence, really a lot of trouble, but still have to correspond to the communication. When the computer literacy, so with UTF-8 this table, probably means that the language appeared around the world, each character corresponds to a number, you hit the word, the computer will transfer this number on it. As many computers on the network, so give each computer coding addresses, in order to distinguish between who I want to send, so with the network address of this concept (that is, the familiar IP address). When you send a message to others, this is the address of the information package on the outside, this way those weird iron box on a level of correspondence sent to this address of the computer. The number of network address, was in the United States, designed only (maximum of 32-bit binary number can represent) 4.2 billion, at least until the year 1990, this number seems a lot, but the United States does not intend at the time of the LAN in other developing countries, due to the nature of the Internet world, the United States left a lot of himself, so seldom assigned to other countries, give the ZG probably 2-3 one hundred million (socialism and capitalism to know that long-term cold war, could be assigned to this number pretty good). If ZG while more than 300 million people online (not through the LAN to access the network, this time is actually several talent with an address, terminology, Network Address Translation (NAT)), IP address will be not enough, XXXX maintenance personnel often say that IP address assignment is over, others unable to get online. Or do you want to hang a web server, you must apply for a broadband with a fixed IP address, can be called the world access to your site (due to the shortage of IP addresses in China, when you disconnect the ADSL dial-up, XXXX on recovery this address is used to other people, as well as government promotion of IPV6 is to solve this problem). Internet easy to innovation in the United States, and probably also for this reason, because people want to hang ZG website to the world access to (broadband fixed IP address XXXX month 800RMB), or difficult, the United States is very free, a lot of public IP address, Zuckerberg likely to succeed.
If you want to get under way, approved networks, you need to obtain cisco (Cisco) certified, three levels CCNA, CCNP, CCNE, from the easy to the complex, said to CCNA exam is very difficult.
Principles calculations under two said. Math computer are carried out inside the binary carried out. 2 + 3, for example, when the operation, when expressed in the middle of the plus sign, or a number, but the computer will see that this figure translated into a digital adder, and then to summing circuit to process. This circuit is an analog of the real world, but here is the sum of the voltage (0 and 0, 1, 0 and 0 was obtained 1,1 0 and 1 have a feed on and 1, only three in the case of binary here it reflects an advantage, if it is a decimal, 2,3,4 ...... have a voltage difference, error-prone). For example, 10 decimal which is full of it up into a 1, dissatisfaction with the draw numbers; the binary is at least 2 to 1 up into one, dissatisfaction with the numbers drawn. Addition and subtraction circuit is the same, is the same multiplication and division circuit. Only the binary 1 and 0, the multiplication circuit design is relatively easy, but the decimal or analog approach. As for the other more advanced operations, such as involution, evolution, remainder ...... these complex arithmetic expressions only, if you want in-depth understanding of the practice, please cramming math.
Three said the next software. Causing the computer difficult to understand and study the root causes or software, because most software has long codes, and incredible algorithms, as well as a variety of personal preferences in accordance with the agreement (if such a convention adopted by many people, it becomes a standard ). For example, when the computer representation of a black and white picture, in fact, he is also expressed in binary, but a special kind of data structure. A screen, divided into many points, each point has coordinates, if you want to spell a map, it is necessary to tell the computer what point (black and white or with different numbers distinction) (with coordinates) is black or white. And then sequentially stored in the hard disk inside. When you need to show it on the screen, but with more color gamut to represent nothing more. Other image formats such as jpg, bmp there is a more complex algorithm. Not so much computer do not know, you might as well say that mathematics too bad.
