【導讀】讀者知道了操作系統(tǒng)是一些軟件模塊的集合，這些模塊完成支持功能，有效地把用戶和硬件隔開。入對軟件較一般的討論。本文不期望教會讀者如何編程序，讀者也不要打算通過讀一本入門書中的一章就。本文的意圖是通過向讀者展示在機器級上程序究竟是什么，然后簡單地討論當開發(fā)一個程序。時程序員應該遵循的過程，從而力求揭示那些常常與軟件有關的奧妙。讓我們從定義開始，程序是引導計算機通過一個過程的一組指令。讀者知道了在每個機器周期內(nèi)處理。器取出并執(zhí)行一條指令。一條典型的指令包含一個操作碼和一組操作數(shù)，操作碼規(guī)定了要完成的功能，操。作數(shù)規(guī)定了存放要被處理的數(shù)據(jù)的存儲單元地址或寄存器編號。告訴一臺假想的計算機把寄存器R3和R4的內(nèi)容相加。就需要四條指令的話，可以想象在一個完整的程序中指令的數(shù)目。因為主存存放數(shù)位，所以程序必須以二進制代碼形式存在。加及結果放在主存中等。給出了所要求的輸出信息和算法，要輸入的數(shù)據(jù)也就確定了結果

　　

【正文】 , a clear procedure must be pleted this thing. 4. Schedule 2 The algorithm for determining what must be done, the next task is to decide what to do purpose is to use the puter to understand the terminology solution to the problem statement. The puter can only be pleted arithmetic operations, pare, replication and requests I / 0, and other operations, so programmers are the basic operation of these restrictions. A good starting point is always the first to identify a small problem solving program. Through practical solution of this algorithm, even in a limited scale algorithm. Programming problems programmers access to the necessary steps. preparation procedures In the implementation phase, programmers solution to the problem into some kind of programming language with a series of statements, each programming language has its own grammar, punctuation and spelling rules. Learning a new language takes time, writing instruction is basically mechanical work. Programming the real secret is not a simple preparation instructions, but to think what was then the directive, which requires logic. Honor is aware of how the process is not a prerequisite for the use of puters. debug and document preparation Once the position process, the programmer must set it up. First to rectify some of its Unconscious errors, such as incorrect punctuation or spelling, and other. Compiler or interpretation of the procedures are usually able to detect these errors, more difficult to detect and correct the logic is wrong, because this type of error is the wrong direction caused. Only instructions correctly is not enough, and procedures must also be correct sequence of instructions group. Repeat, careful programming design is the key, good design simplifies the debugging process. The documentation procedure by paragraphs, ments and other programming to explain or clarify the position of the material in the program debugging phase, documentation is extremely valuable, and it is an effective maintenance procedures foundation. The most useful is in a footnote in the proceedings, these Notes outlined and explained the logic. safeguard Proceedings were transferred, safeguard started. Because it is impossible to thoroughly test many large procedures. In the debugging stage, a number of deficiencies may slip later, months or even years later exposed, the shortings of these are very important maintenance tasks. More important is the maintenance of existing applications to meet the needs of modified procedures. For instance, due to frequent changes in ine tax, wage procedures must be amended frequently. The key is maintaining the plan seriously, plete documentation and excellent programming. 5 preparation user program Be able to play a musical instrument is not the basis of listening to music. Likewise, know how the process is not a prerequisite for the use of puters. For the majority of puter users can not procedures. As a preliminary knowledge of musical instruments you can increase the level of music appreciation, know how the procedures enable you to bee a more efficient puter users. Of course, if you want a puter professional to make a living, for knowledge is the basis of procedures, which do not have to say. Some people found that programming easier, but also made some people find very difficult process. The key is to practice, study for procedures is the only way to for the actual procedure.