计算机英语教案lesson X.pptVIP

1 北师大培训基地 What Is a Computer? A computer is a machine that accepts and processes date into information under the control of a stored program. Date are facts of observations, while information is the meaning we attribute to them. Date flow into the machine as input. Information flows from the machine as output . How does a computer process its data ? What functions .what operations, can it perform Generally, computers can add, subtract, multiply ,divide, compare, copy, request input and output. So can most calculators. What makes a computer different from a calculator? We know that when adding two numbers on a calculator to find the sum , we must provide control by deciding what button to push next, It requires direct human intervention at each step. See you the day after tomorrow! * * The computer processes the data . These three basic concepts of input, processing and output occur in almost every aspect of human life whether at work or at play. For example , in clothing manufacturing , the input is the pieces of cut cloth. The processing is the sewing together of these pieces , and the output is the finished garment. A computer can process data automatically without human intervention. However a computer is not intelligent. It does’t know when to add ,or subtract , or compare, or request input. If it is to fuction without direct human control ,it must be given a set of instructions to guide it , step by step , through a process . The set of instructions is called a program. The program if stored physically inside the machine , making it a stored program. It is the stored program that distinguishes a computer from a calculator.