Java programming 6-basic concepts of Computer Software

Java programming those things 6-basic concepts of computer software by Chen yuefeng from: http://blog.csdn.net/mailbomb Chapter 1 Computer Basics This section describes computer-related knowledge and focuses on basic knowledge related to software programming. In fact, for programming, the foundation of the computer is that the deeper the better, but limited by time and energy, everyone knows very limited, below we will focus on the basic knowledge commonly used in programming. Please actively correct and supplement the omissions. The essential structure of computers is to digitize all content. In fact, software programming uses the same logic to digitize various States that need to be stored. 1.1Basic concepts of Computer Software L As we all know about the concept of software, computers are divided into hardware and software. In fact, hardware, such as hard disks and mainboards, can be hardly touched. According to the professional point, software is a set of command sequences. How can we understand it? Here is a basic example. For example, if you register at school, the school will give you a list, which is generally written as follows: First, where to pay the fee, then receive the certificate, and check the health check, there are at least 10 or more operations. If each operation is regarded as an instruction, this is the essence of the software. Or, according to the computer system of Feng nuiman, computers accept input, process, and feedback results. In fact, the same is true for the software. It provides interfaces for receiving user input and processing based on logic, feedback the results to users, both common software and games. L Why is the computer binary? As we all know, today's computers store and operate data in binary. Why is it binary instead of common decimal? The reason is very simple, because the current computer is an electronic computer, there are only two internal states, so a new binary form is created based on these two States-binary. This greatly simplifies the structure of the electronic computer, and can achieve the mathematical binary by the presence or absence of current, light, and magnetic. In mathematics, 0 and 1 represent the two states respectively. Of course, with the development of science, computers will no longer be electronic computers in the future, and binary may also disappear. L Since the computer is an electronic computer, the minimum unit of storage is a binary bit. One digit has only two values, 0 or 1. Because the unit of BIT is too small, we have designed another concept-byte, Which is abbreviated as B in English. It is specified that one byte is 8 bits, that is, 1B = 8B. For example, an 8-bit or 16-bit host is the smallest data unit that the CPU processes at a time. The larger units are kb, MB, GB, and TB in sequence. The progress between them is the 10th power of 2, that is, 1024, that is, 1kb = 1024b, 1 MB = 1024kb. Here is a simple question. When you buy a hard disk, for example, 160 GB, the manufacturer uses 1000 instead of 1024 in the hexadecimal format. Therefore, after formatting the 160 GB, it is only possible: (160x1000x1000x1000)/1024/1024/1024 = 149 GB