計算機英語：邏輯及邏輯門

Logic and Gates   

　　Logic is an organized method of reasoning.Therefore, logic must be used when making decisions,or when calculating or processing data. One logical methodology used in the design of all digital computers  is called Boolean Algebra. It was developed by anEnglishman George Boole around 1947．In 1938，Claude E．Shannon, a research assistant at MIT,published a paper describing how Boolean algebra could be used to represent two-state, or binary, circuits used in today's modem digital computers． 

　　Boolean algebra uses three basic opcrators：logical multiplication,called the AND function;logical add1tion, called the OR function; and logical complementation，called the NOT function. The variables in Bolean algebra is binary. That is, the resulting Vaiiable of an operation or a set of operations can have only one of two values: 1 or O.Varlables may also be interpreted as being true or false, or yes or no.   

　　Gates and inverters are circuits that are used to implement the basic logic functions. An inverter is alogic circuit that has one input and one output. A gate is a logic circuit that has at least two input and one output. These gates and inverters are made up of transistors diodes，and resistors．In the present tech-nology they are always packaged as integrated circults, and there are anywhere from two to many thou-sand gates and/or inverters in a single chip. All the Flip-flops，registers，counters, adders, and otherlogic circuits in a computer arc made up of these basic circuits．   

　　To develop all understanding of how gates and inverters are used in a computer，we must first de-velop an understanding of the logic functions they canperform. All input and output variables can have only one of two possible states-true or false. Because this true, Boolean algebra becomes a valuable tool tothe designer and to the technician because we canutilize the laws and theorems of Boolean algebra to simplify complex circuits and to help us understand existing circuits and systems.

翻譯:

邏輯及邏輯門    

　　邏輯是推理的一種有組織的方法，因此，當做決定或者計算或處理數據時，必須采用邏輯，在設計所有數字計算機時所采用的一種邏輯方法（學）叫做布爾代數。 它是由英國人喬治布爾于1847年左右研究出來的。 1938年，麻省理工學院的一位研究助教克勞德香農發表了一篇文章，其中論述了布爾代數如何可被用來表示在當今現代數字計算機中所用的兩態（或二進制）電路。

　　布爾代數采用三種基本運算，邏輯乘也叫做“與”函數；邏輯加也叫做“或”函數；邏輯補，也叫 做“非”函數，布爾代數中的變量是二進制的，就是說，一種或一組運算的最終變量，僅能具有二值之一：I或0.變量也可被解釋為真或 假，是或否（非）。    

　　門和反相器是用來實現基本邏 輯函數的電路，反相器是具有一個輸入（端）和一個輸出（端）的邏輯電路。門是至少具有兩個輸入 （端）和•個輸出（端）的邏輯毛路。這些門和反相器是由晶體管、 二極管及電陰器組成的，在現代技 術中，它們總是以集成電路的形式加以封裝，總是集成了從兩個到數千個門和（或）反相器在單個芯片上。在計算機中，所有的觸發器、 寄存器、計數器、加法器以及其他邏輯電路，都是由這些電路構成的。

　　為了提高對在計算機中怎樣天用門和反相器的理解，首先，我們必須提高對門和反相器所能執行色 邏輯函數的理解，所有的輸入和轉出變量只能具有兩個可能狀態之一真或假。這一點是對的．所以布爾代數對于設計師和技術人員成為有價值的工具。因此我們可以利用布爾代數的定律和定理簡單復雜的電路，并且幫助我們理解現存的電路及系統。

原文轉自：http://www.kjueaiud.com