新編計算機專業(yè)英語chapter 04

1、Chapter 4 Storage 新編計算機專業(yè)英語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:一般現(xiàn)在時 科技英語中多用動詞的現(xiàn)在時，尤其一般現(xiàn)在時來表示“無時間性”的一般敘述。當敘述事實或真理，或者客觀地表述定義、定理、方程式、公式和

15、圖表等，都可以運用這一語法特征。 例如: An optical disc is an electronic data storage medium that can be written to and read using a low-powered laser beam. 光盤是一種電子數(shù)據(jù)存儲介質，可以使用低功率激光束寫入和讀取數(shù)據(jù)。The CPU firstly sends a number called memory address, through an address bus, that indicates the desired location of data. CPU首先通過

16、地址總線發(fā)送一個內存地址的編號，指定所需數(shù)據(jù)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. 處理器緩存，也稱為CPU緩存，被運用于計算機的中央處理單元，目的是縮短CPU訪問內存的平均時間。練習（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.請把以下英文句子翻譯成為中文。 （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