【導(dǎo)讀】1984年2月23日，BusinessWeek頭版醒目地排印了通欄大標(biāo)題“軟件：新動(dòng)力”。到題目，禁不住笑了，評論說這話說得大約晚了10年。今天，在計(jì)算機(jī)的歷史上，軟件首次超越了硬件，成為許多企業(yè)、產(chǎn)品以及系統(tǒng)。成功的關(guān)鍵要素。其實(shí)，軟件常常是區(qū)別彼此的主要因素。軟件提供的信息，因其完整與適時(shí)，才使得。公司與其競爭對手有所區(qū)別。嵌入式軟件提供的智能和功能常常使兩種相似的工業(yè)品或消費(fèi)品有所區(qū)別。在計(jì)算機(jī)時(shí)代的前30年內(nèi)，首要的挑戰(zhàn)是開發(fā)能降低數(shù)據(jù)的處理和存儲費(fèi)用的硬件。昨天一臺大型計(jì)算機(jī)上的功能，今天可以在單片集成電路上獲得。的暢銷書中，Osborne[OSB79]將其稱為“新的工業(yè)革命，’；Toffler[TOF80]將微電子技術(shù)的到來稱為人類。隨著計(jì)算機(jī)系統(tǒng)數(shù)目的增長，計(jì)算機(jī)軟件程序庫開始膨脹。20年前，能夠明智地描繪出“計(jì)算機(jī)軟件”是什么的人不足1％?！败浖S”這一。缺欠排除后，在某一段時(shí)間內(nèi)，故障率降至一個(gè)較低的穩(wěn)定的水平。

　　

【正文】 ders are executable software in the form of the bottom. Hexadecimal or other special code can be used to represent the CPU can lead to specific steps to deal with the binary bit mode. Machine code, assembly language (machinelevel language), and highlevel programming languages are often referred to as the first three generations of puter language. The use of a language, programmers must take into account both the information provided should also consider whether the structure of the control process itself. Therefore, the process of the first three generations of language as language. In the past 10 years, there has been a group of fourth generation language or process language. Nonprocess language requirement does not require software developers details of the process, it is referred to the procedure provides for the appointment rather than the result of the oute of the requirements to achieve its behavior [COB85]. The results show that support software translated into machine executable. So far, the fourthgeneration language (4 GLs) database has been used for other mercial applications and data processing areas. Software applications The software can be applied to the prior provisions of the steps (algorithm) has been defined under any circumstances (this obviously does not meet the rules example is the expert system software). Information content and software applications uncertainty is to determine the nature of the important factors. Content refers to the input and output of the significance of the information and forms. For example, many mercial applications that use highly structured losers were data (databases) and generates formatted statements. Automatic machine control (for example, NC) software to accept a limited form of the structure of discrete and continuous data quickly from the machinegenerated orders. Information certainty that the losers were the timing and sequencing data predictability. Engineering analysis procedures for accepting predefined sequence data, analysis algorithm for implementation, and to give statements or chart form of result data. This application is uncertainty. On the other hand, a multiuser operating system to accept arbitrary changes in the content and timing of transmission, the implementation of external circumstances may be interrupted algorithm and generates with the environment and time for a change in the output function. With the application of these characteristics is uncertain. It is difficult to find a meaningful general classification software applications (Law). With the increase in plexity of the software, the full and plete separation would not exist. Below the software described the breadth of potential applications software. System software System software for other services the procedures set procedures. Some system software (for example, the piler, editor and file management utility) dealing with plex information structure but identified. Other applications (such as operating system ponents, drivers and remote munications processors) to deal with a large number of nondeterministic data. No matter under what circumstances, the system software is characterized by: frequent interaction with the puter hardware。 Frequent use of multiuser。 Demand scheduling, resource sharing and management of the plex process of concurrent operation。 Complex data structures and multiple external interfaces. When the realtime software that could happen at the time of its realtime measurement, analysis and control software called realtime software. Realtime software ponents include: collection of information from the external environment and formatting of the data acquisition。 Transmission analysis of the information required。 On the external environment to respond control / output and coordination to ensure that all the remaining ponents realtime response (usually from 1 millisecond to 1 min) monitoring ponents. It should be noted the term realtime and interactive or block different. Realtime system must be strictly within the time limit to respond. Usually, the interaction (or timesharing) system will exceed the response time without causing catastrophic oute. Commercial software business information processing is the largest single software application areas. Discrete the system (such as payroll software, or / payment software and inventory software, etc.) have been developed to the Management Information System (MIS) software, the software can visit one or more mercial information, including large databases. The field of application software reestablishment of existing data structures to facilitate the business operation or make management decisions. In addition to the traditional data processing tasks, business software also includes an interactive calculation (for example, pointofsale transaction processing). Intelligent embedded software products have bee almost every customer and industrial market platitudes. The presence of embedded software in readonly memory, to market to customers and industrial control products and systems. Embedded software to plete the secret extremely limited function (for example, microwave ovens for small keyboard control) or provide an important function and the ability to control (for example, the number of cars on the features, such as fuel control, dashboard display and braking system, etc.). Personal puter software in the past 10 years, the personal puter (PC) software market is extremely prosperous. Word processing, spreadsheet, puter mapping, entertainment, database management, personal and mercial financial applications, external work or database access hundreds of applications, such as only a few examples. Indeed, in the area of software, PC software still some representatives of the most creative software