Ch.9 The Storage Unit 存貯部件

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1 Ch.9 The Storage Unit 存貯部件
S.4-5 CS&IT CE Course 中四及中五電腦與資訊科技會考課程

2 基本貯存單位 Basic Memory Unit
數據和指令均以二進制數字或數位來表示 Data and instructions are represented by binary digits or bits

3 基本貯存單位 Basic Memory Unit
8 位元bits = 1字節bytes 8位元的字節作為基本的存貯單位 The basic unit of memory is a byte

4 主存貯器 Main Memory 有一個獨特的地址 has a unique address 主存貯器 RAM 01 02 03
04 Read A 05 Read B 06 07 08 09

5 主存貯器 Main Memory 電腦會根據某個字節的地址，來存取該字節的數據或指令
Computer references bytes of data or instructions, it refers to their addresses 主存貯器 RAM 01 02 03 04 Read A 05 Read B 06 07 08 09 1byte

6 主存貯器 Main Memory 中央處理器能把某個數目的二進制位視作一個單元，一次過進行處理，這個數目稱為字長
The number of bits that a CPU can process as a unit is called its word size 字長越大，電腦處理的速率越高 The larger the word size, the faster the processing

7 主存貯器 Main Memory 隨機存取存貯器 Random Access Memory (RAM)
唯讀存貯器 Read Only Memory (ROM) RAM ROM

8 隨機存取存貯器 (RAM) 貯存當前正要執行的程序及處理的數據
Holds the programs currently being executed and the data being processed 是一個暫時的存貯區域 A temporary storage area 電腦被關掉後，貯存的內容會立即消失Stored contents immediately vanish when the computer is turned off

9 唯讀存貯器 (ROM) 永久貯存由製造商裝入的系統程 序和數據
holds system programs and data that are permanently recorded 它是一個永久的存貯區 a permanent storage area 內容只能被讀取，不能被重寫 contents of ROM memory can be read out, but cannot be written over 電腦被關掉後，貯存的內容依然會被保留 stored contents will be retained when the computer is turned off

10 輔助貯存器 Secondary Storages
不能被中央處理器直接存取 NOT directly accessible by the CPU 可永久貯存大量數據及程序以備將來之用 can hold large amount of data and programs permanently for future use

11 輔助貯存器 Secondary Storages
輔助存貯器可分為兩種： Two main types of secondary storage devices: 磁存貯設備 Magnetic storage devices 光存貯器設備 Optical storage devices

12 1) 磁存貯設備 Magnetic storage devices
軟磁碟 Floppy disk 軟磁碟上的數據是貯存在環形磁道上Data are organised on a floppy disk in rings called tracks 每條磁道分為多個不可見的區域，稱為扇區 Each track is divided into invisible section known as sectors

13 磁存貯設備 Magnetic storage devices
軟磁碟機 透過軟磁碟機，我們可讀出貯存於軟磁碟上的數據，或把數據寫入軟磁碟中 A floppy disk drive is a machine that allows data to be read from a floppy disk or written onto a floppy disk

14 磁存貯設備 Magnetic storage devices
硬磁碟 Hard disk 由一塊或多塊金屬片組成的磁碟組 consists of one or more metallic platters organised into a disk pack 硬碟 Hard disk drive

15 磁存貯設備 Magnetic storage devices
硬磁碟在兩方面比軟磁碟優勝： Hard disks have two advantages over floppy disks 容量較大larger capacities 存取速度較快shorter access time A hard disk drive VS.

16 磁存貯設備 Magnetic storage devices
硬磁碟機 Hard disk drive 可攜式的硬磁碟機 Removable hard disk drive

17 磁存貯設備 Magnetic storage devices
磁帶 Magnetic tape 最便宜的後備存貯媒體 the cheapest secondary storage medium 適合用來貯存大量數據 suitable for storing a large amount of data

18 磁帶 Magnetic tape 很少用於個人電腦上 seldom use with personal computers
是小型電腦和大型電腦的主要備份貯存設備 primary means of backup for minicomputers and mainframes

19 磁帶 Magnetic tape 兩類常見的磁帶 two common types of magnetic tapes:
盒式磁帶Cartridge Tape 捲盤式磁帶 Reel-to-reel Tape

20 光存貯器設備 Optical storage devices
唯讀光碟 Compact-disc Read Only Memory (CD-ROM) drive 數據由生產商永久貯存在唯讀光碟內 Data are pre-stored permanently on a CD-ROM by the manufacturer 唯讀光碟 CD-ROM

21 光存貯器設備 Optical storage devices
唯讀光碟機 Compact-disc Read Only Memory (CD-ROM) drive 透過唯讀光碟機，你可從唯讀光碟讀取數據，但不可在光碟上寫入數據 You may read data from a CD-ROM disk by a CD-ROM drive, but not write data on it 唯讀光碟機CD-ROM drive

22 光存貯器設備 Optical storage devices
可寫光碟機CD writer 能在可記錄光碟上讀取或寫入數據 can read and write data on recordable CDs 可寫光碟機 CD writer

23 光存貯器設備 Optical storage devices
可記錄光碟機主要有兩種形式： two types of recordable CD formats: 可錄光碟機 CD-R ：容許在可錄光碟上寫入數據一次，然後可多次從光碟上讀取數據 A CD-R drive allows us to write data once on a CD-R disk and read from it many time 可寫光碟機 CD-RW ：容許在可寫光碟上多次寫入數據，及多次從光碟上讀取數據 A CD-RW drive allows us to write data on and read from a CD-RW disk many times

24 可寫光碟機 CD-writer 可錄光碟與可寫光碟CD-Rs and CD-RWs 可寫光碟機 CD writer

25 光存貯器設備 Optical storage devices
數碼影像光碟Digital Versatile Disk (DVD) drive 具有更大存貯容量 optical disks with even higher storage capacity 常用來貯存電影 usually use to store movies

26 數碼影像光碟數碼影像光碟Digital Versatile Disk (DVD) drive
只可利用數碼影像光碟機從數碼影像光碟讀取數據，而不能在光碟上寫入數據 we can only read from but not write to a DVD using a DVD drive

27 數碼影像光碟Digital Versatile Disk (DVD) drive
數碼影像光碟 DVDs 數碼影像光碟機 DVD drive

28 堂課 Class work P.147 MC Q.1-9 P.149 Q.8

29 功課 Homework P.148 Q.1-7