Inside your computer - Bettina Bair

深入你的电脑- 贝蒂娜 贝尔

翻译人员: Boxi Sun 校对人员: Zhiting Chen

Do you remember when you first realized

还记得你是什么时候第一次发现

that your computer was more

你的计算机不仅仅

than just a monitor and keyboard?

只是一个显示器和键盘的？

That between the mouse click and the video playing,

从鼠标的点击到视频播放，

there was something that captured your intention,

这之间有什么东西捕捉到了你的意图，

understood it,

理解了它，

and made it real?

并将其变为现实？

What is that something?

这个东西到底是什么？

Is it gremlins?

难道是小妖精？

Let's imagine that we can shrink down

让我们假想一下自己可以缩小

to the size of an electron

到和一个电子那么大

and inject ourselves into a click of a mouse.

并把自己注入到鼠标的一次点击中去。

If you took your mouse apart,

如果你把鼠标拆解了，

you'd see that it's really a very simple machine.

你会看到其实它是一个非常简单的机械设备。

It has a couple buttons

它有一对按键

and a system for detecting motion and distance.

和一个用于检测动作和距离的系统

You might have an optical mouse

你用的可能是光电鼠标

that makes these measurements with lights and sensors,

它借助光以及传感器来完成这些检测，

but older ones did this with a hard rubber ball

但老款鼠标通过一个硬橡胶球

和几个塑料轮子来完成。

and some plastic wheels.

Same concept.

同样的原理。

When you click the button on your mouse,

当你点击鼠标上的按键时，

it sends a message to the computer

它会发向电脑发出一个

with information about its position.

包含其位置信息的消息。

When your mouse click is received,

当你的鼠标点击消息被收到，

it's handled by the basic input/output subsystem.

它会被基本输入/输出子系统来处理。

This subsystem acts like the eyes and ears

这个子系统的作用就像是计算机的眼睛，耳朵，

and mouth and hands of the computer.

嘴和手一样。

Basically, it provides a way for the computer

它主要给计算机提供了一个与

其外界环境交互的途径。

to interact with its environment.

But it also acts like a buffer

但它也同时起到了缓冲的作用

to keep the CPU from being overwhelmed by distractions.

以保证中央处理器不至于被干扰信息所淹没。

In this case, the I/O subsystem decides

这里，输入输出子系统决定

that your mouse click is pretty important

你的鼠标点击信息非常重要

so it generates an interrupt to the CPU.

所以它生成了一个打断信号并发给了中央处理器。

"Hey, CPU! Got a click here."

“嘿，中央处理器！这儿有一个点击信息。”

The CPU, or central processing unit,

CPU，全称是中央处理器，

is the brains of the whole computer.

是整个计算机的大脑。

Just like your brain doesn't take up your whole body,

就像你的大脑不会占据你的整个身体一样，

the CPU doesn't take up the whole computer,

中央处理器也不会占据整个计算机，

but it runs the show all the same.

但尽管如此，它还是操控着整个计算机。

And the CPU's job, its whole job,

中央处理器的任务，也是它的全部任务，

is fetching instructions from memory

就是从内存里获取指令

and executing them.

并执行计算。

So, while you're typing, typing, typing,

所以，当你在不断地敲击键盘，

maybe really fast,

速度可能真的很快，

like 60 words a minute,

比如一分钟60个字，

the CPU is fetching and executing

中央处理器也在获取和执行

billions of instructions a second.

每秒数以亿计的的指令。

Yes, billions every second:

是的，每秒数以十亿计：

instructions to move your mouse around on the screen,

这些指令包括你在屏幕上挪动鼠标，

to run that clock widget on your desktop,

在桌面上运行一个时钟组件，

play your internet radio,

运行网络收音机，

manage the files you're editing on the hard drive,

管理你在硬盘上编辑的文件，

and much, much more.

如此等等。

Your computer's CPU is one heck of a multitasker!

你计算机的中央处理器是个真正的处理多任务的能手！

"But oh my gosh

“但我的天啊

there's a very important mouse click

现在有一个非常重要的鼠标点击信息

coming through now!

正传进来！

Let's drop everything now and deal with that!"

让我们先把其他的事情放一放来处理它！“

There are programs for everything

中央处理器处理每个任务

that the CPU does.

都有其对应的程序。

A special program for the mouse,

一个专门的鼠标程序，

for the clock widget,

专门的时钟组件的程序，

for the internet radio,

专门的网络收音机的程序，

and for dealing with letters sent by the keyboard.

和专门的用于处理键盘打出的字母的程序。

Each program was initially written by a human

每个程序最开始都是人们

in a human-readable programming language,

用人类可读的编程语言来编写的，

like Java,

像Java语言,

C++,

C++语言,

or Python.

或者Python语言。

But human programs take up a lot of space

但人工程序会占据很大的空间

and contain a lot of unnecessary information to a computer,

而且包含很多的对计算机来说不必要的信息，

so they are compiled and made smaller

所以它们会通过编译被缩小

and stored in bits of ones and zeros in memory.

并记录在许多由0和1二进制位组成的信息里存入内存。

The CPU realizes that it needs instructions

中央处理器发现他需要指令

for how to deal with this mouse click,

来明白如何去处理这次鼠标点击，

so it looks up the address for the mouse program

所以他去查询鼠标程序的地址

and sends a request to the memory subsystem

并向内存子系统发出一个请求

来获取存储在相应位置的指令。

for instructions stored there.

Each instruction in the mouse device driver

每个在鼠标设备驱动器里的指令

is duly fetched and executed.

都会被及时的获取并加以执行。

And that's not nearly the end of the story!

可这还远远没有结束！

Because the CPU learns that the mouse was clicked

因为中央处理器得知鼠标在被点击的时候

when the cursor was over a picture

光标是在显示器屏幕里

of a button on the monitor screen,

的一个按钮图片上的。

and so, the CPU asks memory for the monitor program

所以，中央处理器会从内存里获取显示程序

to find out what that button is.

来弄清这个按钮是什么。

And then the CPU has to ask memory

接着，中央处理器会从内存中

for the program for the button,

获取这个按钮的程序，

which means that the CPU needs

这意味着中央处理器需要再次调用

the monitor program again

显示程序

to show the video associated with the button,

来显示与这个按钮相关联的视频，

and so it goes.

这样视频才能得以播放。

And let's just say there are a lot of programs involved

可以说，甚至在你点击

before you even see the button on the screen

屏幕上的这个按钮使其高亮之前

light up when you clicked it.

已经有很多的相关程序被调用了。

So, just the simple task of clicking your mouse

所以，仅仅一个简单的点击鼠标的任务

means visiting all of the critical components

意味着要访问你计算机架构里

of your computer's architecture:

所有的重要组成部分：

peripherals,

外设，

the basic input-output system,

基本输入-输出系统，

the CPU,

中央处理器

programs,

程序，

and memory,

和内存，

and not one gremlin.

和小妖精一点儿关系没有。