2023年7月17日发(作者：)

第5讲

一、课文

Main Memory（ROM & RAM）

The term “main memory” is usually used to refer to the internal storage locations of a

computer. It holds data and programs during processing. There are two types of main memory:

ROM and RAM.

ROM stands for Read Only Memory. It is usually built right into the computer. Since ROM

contains instructions to the CPU on how to perform its basic processing tasks, such as the

instructions to start computer, to install printer etc., ROM must be protected form change.

Furthermore, the CPU always reads from this memory, but not writes to it. That is why it is called

Read Only Memory.

Whenever new information is entered, it must be stored somewhere in the computer’s

memory. Later, the CPU must also be able to get this information from memory. This is why RAM

is needed. The CPU can both write to and read from RAM. RAM is called Random Access

Memory because the CPU can go directly to any memory location in it. But RAM only holds the

data temporarily. As soon as you switch the computer off, all that information disappears from the

RAM. So it is necessary to form a good habit of saving your work every few minutes.

二、参考译文

内存（只读存储器和随机存取存储器）

“内存”这个术语通常用来指计算机内部的存储单元，它在计算机操作过程中存储数据和程序。有两类内存，即ROM（只读存储器）和RAM（随机存储器）。

ROM是只读存储器的简称，通常都直接内置于电脑之中。因为ROM含有指示CPU如何执行基本操作任务的指令，例如启动计算机、安装打印机的指令，所以要保护ROM以免遭受更改。而且，CPU总是从此存储器中读取，但不能写入。这也就是它为何被称为“只读存储器”的原因。

每当新信息键入时，就必须得存储在电脑存储器的某一处。其后，CPU必须还能够从存储器中取得此信息——这就是需要RAM之处。CPU不但可以将信息写入RAM，也可以由RAM读取信息。RAM所以称为随机存取存储器，是因为CPU能够直接进入RAM的任何存储单元。不过，RAM保存数据只是暂时的，只要关掉电脑，RAM的所有信息都会消失不见。因此，用户有必要养成每隔几分钟就保存工作内容的好习惯。

三、重点难点讲解

1、term 学期, 术语

2、refer to 指，提到, 谈到

3、internal 内部的

internal debts 国内债务

internal data 内部数据

internal modems 内部调制解调器

4、location 位置, 场所, 区域，存储单元，地址栏的网址

URL unified resource location 统一资源定位符

5、hold 存储

6、data 数据（复数） datum 单数

7、stand for 代表，象征 8、built into 内置于 built-into 内置的

9、instruction 指令

10、Since ROM contains instructions to the CPU on how to perform its basic processing tasks,

such as the instructions to start computer, to install printer etc., ROM must be protected form

change.

ROM must be protected form change. 是主句， 前面的Since引导的是原因状语从句

be protected form 保护„„免受„„

11、Whenever 每次„„的时候，注意与when的区别（当„„的时候）

12、temporarily 临时地 （Windows的temp目录存放临时文件）

13、as soon as 一„„就„„

14、switch off 关

switch 开关, 电闸, 转换, 转变

15、form a good habit of doing sth. 养成良好习惯做某事

16、every few minutes 每隔几分钟

every 每隔„„一次

eg. Please water the flowers every three days. 请给花每隔三天浇一次水。

四、练习

1. Only data can be stored in the main memory of the computer.

2. The contents of the ROM are changeable.

3. The CPU and the main memory work closely together.

4. We must put the information in the memory before it can be processed by the computer.

5. The CPU can find what it wants in the RAM directly.