人教版高中英语选修计算机英语TheSystemUnit.ppt

The Components of the System Unit Objective In this unit, you will learn: Describe the components in the system unit. Explain how the CPU processes data. Differentiate among the various types of memory. Explain the difference between a serial, a parallel, and a USB port. Free talk 1. Do you have a computer? 2. Do you know the structure of a computer? 3. What do you use a computer for? 4. Do you like playing computer games? Why? Or why not? The System Unit All sizes of computers have a system unit. system unit system unit system unit The System Unit What is the system unit? Case that contains electronic components of the computer used to process data. The System Unit What are common components inside the system unit? Processor Memory Adapter cards: sound card, video card Ports Drive bays Power supply The System Unit What is the motherboard? Main circuit board in system unit. Contains adapter cards, processor chips and memory chips. The System Unit What is the motherboard? Processor What is central processing unit? Interprets and carries out the basic institutions that operate a computer. Control unit directs and coordinates operation in the computer. Arithmetic logic unit (ALU) performs arithmetic, comparison, and logical operations. Also called the processor. Data Representation How do computers process data? separate states on off 1 0 Use a binary system to recognize two states. Use number system with two digits: 0 and 1 called bits. Data Representation Two popular coding schemes to process data: ASCII-America Standard Code for Internet Interchange EBCDIC-Extended Binary Coded Decimal Interchange Code Memory Three basic groups of items: Operating system and other system software→control computer and devices Application programs→perform a task Data processed by the application programs Memory How is memory measured? By number of bytes