新编计算机专业英语chapter 04

1、Chapter 4 Storage 新编计算机专业英语IntroductionIn this chapter, we present an overview of Storage hardware , The two main types of storage devices are the primary storage, also called memory, and the secondary storage . After you have read this chapter, you should be able to distinguish between primary and

2、secondary storage devices, describe the different types of memory, describe traditional and modern secondary storage devices. . Section A. Primary Storage What is primary storage? Primary storage, presently known as memory, is the only one directly accessible to the CPU. The large-capacity main memo

3、ry include RAM, ROM and CMOS. Besides main memory, traditionally there are two more sub-layers: processor registers and processor cache. 2. Primary storage devicesRAM There are several types of RAM: DRAM, SDRAM, DDR SDRAM, etc. ROM Read-only memory (usually known by its acronym, ROM) is a class of s

4、torage media used in computers and other electronic devices. Because data stored in ROM cannot be modified (at least not very quickly or easily), it is mainly used to distribute firmware (software that is very closely tied to specific hardware, and unlikely to require frequent updates). CMOS The non

5、-volatile memory was historically called CMOS RAM or just CMOS because it traditionally used a low-power CMOS memory chip , which was powered by a small battery when the system power was off. Non-volatile BIOS memory CMOS battery Processor registers Processor registers are located inside every proce

6、ssor. Processor cache a cache is a temporary storage area where frequently accessed data can be stored for rapid access. Processor cache, or CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. Section B Secondary Storage 1. What is seco

7、ndary storage? Secondary storage, or storage in popular usage, differs from primary storage in that it is not directly accessible by the CPU. Secondary storage does not loose the data when device is powered downit is non-volatile. Secondary Storage devices 2. Secondary storage devices.Hard disk driv

8、e A hard disk drive(HDD), commonly referred to as a hard drive, hard disk, or fixed disk drive, is a non- volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Floppy disk A floppy disk, or diskette can record data as magnetized spots on tra

9、cks on its surface .Optical Discs An optical disc is an electronic data storage medium that can be written to and read using a low-powered laser beam. CD (Compact Disc) DVD Blu-ray DiscFlash memory Flash memory is a kind of solid state, non-volatile computer memory that can be electrically erased an

10、d reprogrammed. Other Storage Devices Holographic Versatile Disc Portable Media Players (PMPs) Mobile phone Removable disk cartridgesSection C Review & ReadingReview -Multiple Choice.1.Which of the following provides flexibility and expandability for a computer system? A.ROMB.RAMC.CMOSD.Cache2.All o

11、f the following are commonly used units of measurement to describe memory capacity, except: A.Megabyte (MB).B.Gigabyte (GB).C.Terabyte (TB).D.Nanobyte (NB). 3.When you reboot your system, the computer takes instructions to start from the A.DRAM.B.SDRAM.C.DDR.D.ROM.4.Special service sites available o

12、n the Web that provide users with storage are called A.solid state storage.B.Internet hard drive.C.Internet flash storage.D.DAT.5.Storage that retains its data after the power is turned off is referred to as A.volatile storage.B.sequential storage.C.direct storage.D.nonvolatile storage.6.The process

13、 of accessing information from secondary storage devices is referred to as A.backing up.B.restoring.C.writing.D.reading.7.The _ indicates how much data a particular storage medium can hold. A.accessB.capacityC.memoryD.storage8.The 2HD on a floopy diskette label means A.2 MB storage capacity.B.two-si

14、ded, high density.C.2 MB hard disk.D.two-sided hard disk.9.The hard disks disk surface is scratched and some or all of the data is destroyed when there is a A.head crash.B.cylinder crash.C.track crash.sector crash.10. 3. Grammer:一般现在时 科技英语中多用动词的现在时，尤其一般现在时来表示“无时间性”的一般叙述。当叙述事实或真理，或者客观地表述定义、定理、方程式、公式和

15、图表等，都可以运用这一语法特征。 例如: An optical disc is an electronic data storage medium that can be written to and read using a low-powered laser beam. 光盘是一种电子数据存储介质，可以使用低功率激光束写入和读取数据。The CPU firstly sends a number called memory address, through an address bus, that indicates the desired location of data. CPU首先通过

16、地址总线发送一个内存地址的编号，指定所需数据的位置。Processor cache, or CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. 处理器缓存，也称为CPU缓存，被运用于计算机的中央处理单元，目的是缩短CPU访问内存的平均时间。练习（1）Computer hardware is the equipment involved in the function of a computer and consist

17、s of the components that can be physically handled.请把以下英文句子翻译成为中文。 （2）In contemporary usage, memory usually refers to a form of semiconductor storage known as random access memory (RAM) and sometimes other forms of fast but temporary storage. （3）The two main types of storage devices are the primary storage, also called memory, and the secondary storage. （4）In electronic engineering, DDR3 SDRAM (or double-data-rate three synchronous dynamic random access memory) is a random access memory technology used for high speed storage of the working data of a c