《Operating System Concepts》學習第 2 天，p2-p8 總結，總計 7 頁。

一、技術總結

1.operating system

An operating system is software that manages a computer’s hardware。

2.system bus

data bus, address bus, control bus 統稱為 system bus。

二、英語總結(生詞：5)

1.myriad

(1)myriad: myrias("ten thousand")

Originally, myriad refered to the number ten thousand(10,000), but over time, it came to mean a very larege or countless number of sth.

示例：By now, you can probably see that the term operating system covers many roles and functions. That is the case, at least in part, because of the myriad designs and uses of computers(《Operating System Concepts》第5頁)。

2.spacecraft

(1)space

c/u. an empty area(空間), an empty area outside Earth's atmosphere(宇宙，太空).

(2)craft

The sense expanded in Old English to include "skill, dexterity; art, science, talent" .

The meaning "small boat" is recorded by 1670s, probably from a phrase similar to vessels of small craft and referring either to the trade they did or the seamanship they required, or perhaps it preserves the word in its original sense of "power."

(3)pacecraft: space + craft.

c. a vehicle used for travel in space(太空飛船，宇宙飛船).

3.diversity

(1)diversify

assimilated form of dis-("aside") + vertere("to turn"). vi/vt. diversify literally means "to make different or varied.", to make more varied or different(使.....多樣化)。

(2)diverse

adj. including many different types(多種多樣的).

(3)diversity

s/u.the fact of many different types(多樣性).

示例：To explain this diversity, we can turn to the history of computers(《Operating System Concepts》第5頁)。

4.trajectory

(1)trajectory: trans-("across") + ject(from jacere"to throw")

c.Originally, trajectory referred to the path of a thrown object, and it later expanded to mean the course(過程) of anything moving or developing over time(軌跡).

示例：Computing started as an experiment to determine what could be done and quickly moved to fixed-purpose systems for military uses, such as code breaking and trajectory plotting, and governmental uses, such as census calculation(《Operating System Concepts》第5頁)。

5.adequate

(1)adequate: ad-("to") + aequre("to make equal")

adj. equal to what is needed or desired, sufficient.It means matching a requirement or being sufficient for a purpose(足夠的，合乎需求的).

示例：How, then, can we define what an operating system is? In general, we have no completely adequate definition of an operating system(《Operating System Concepts》第5頁)。

關于英語的注解同步更新匯總到 https://github.com/codists/English-In-CS-Books 倉庫。

三、其它

本來計劃是每天閱讀 30 頁的，但實際讀下來卻差距甚大——今天只閱讀了 6 頁，主要原因在于：一、英文單詞。今天遇到很多生詞，也有很多單詞之前遇到過，但是學得不夠細，又忘記了。二、對名稱的不理解。例如：cable TV tuners(有限電視調諧器)，從字母上來說，英文、中文都能看懂，受限于沒有見過實物，僅僅只是在頭腦中形成一個概念，沒有具象的理解。

本來想湊夠了 30 頁再發，算了，接受現實，慢慢來，不管每天的進度快慢，讀一點是一點，不斷記錄，不斷總結-日拱一卒，功不唐捐。

四、參考資料

1. 編程

(1) Abraham Silberschatz，Peter Baer Galvin，Greg Gagne《Operating System Concepts》：https://book.douban.com/subject/30272539/

2. 英語

(1) Etymology Dictionary：https://www.etymonline.com

(2) Cambridge Dictionary：https://dictionary.cambridge.org

歡迎搜索及關注：編程人(a_codists)