Chapter OneBit比特: Binary DigitBit Patterns:A string of bitsGate 门电路: A device （装置）that computes a Boolean operationFlip-flop 触发器: A circuit built from gates that can store one bit.Main Memory 内存: bit reservoir,a large collection of circuits for the purpose of storing data Cell: A unit of main memory (typically 8 bits which is one byte字节)Random Access Memory (RAM): (随机访问存储器)Memory in which individual cells can be easily accessed in any orderDynamic Random Access Memory (DRAM):(动态RAM) RAM composed of volatile memory.To wit ,it is the memory stores the bits as tiny electric charges,which need refreshing repeatly mang times in a second.In recognition of this volatility,memory constructed from such technology is call DRAM.SRAM Static Random Access Memory 一种具有静止存取功能的内存，不需要刷新电路即能保存它内部存储的数据。
不像DRAM内存那样需要刷新电路，每隔一段时间，固定要对DRAM刷新充电一次，否则内部的数据即会消失，因此SRAM具有较高的性能，但是SRAM 也有它的缺点，即它的集成度较低，相同容量的DRAM内存可以设计为较小的体积，但是SRAM却需要很大的体积Mass Storage Systems大容量存储系统：Additional memory devices,including Magnetic Systems、Disk、Tape、Optical Systems(视觉系统)、CD、DVD and Flash Drives。
File 文件: A unit of data stored in mass storage systemBuffer(缓冲区):A memory area used for the temporary storage of data (usually as a step in transferring the data)USB universal serial bus 通用串行总线ISO The International Organization for S tandardization 国际标准化组织 a worldwide federation of srandardization bodies各国标准化团体（ISO成员团体）组成的世界性的联合会。
ASCII American S tandard Code for Information InterchangeChapter TwoComputer Architecture 计算机体系结构Computer architecture in computer engineering is the conceptual design and fundamental operational structure of a computer system.Central Processing Unit (CPU) or processor中央处理器:the circuitry in a computer that controls the manipulation of data. A CPU consist of Arithmetic/Logic unit and Control unit.(算术/逻辑单元和控制单元)Registers寄存器Cells in CPU for temporary storage of information.General-purpose register通用寄存器Special-purpose register特殊寄存器Bus 总线:a collection of wires connecting CPU and main memory for the purpose of tranferring bit patterns.Stored program concept 程序存储概念:the idea of storing a computer’s program in its main memory.Motherboard主板central circuit board in some complex electronic systemsReduced Instruction Set Computer(RISC)精简指令集计算机Complex Instruction Set Computer (CISC)复杂指令集计算机Op-coder操作码the elementary operationsOperand操作数more detailed information about the operation，usually refer to where the data to be stored and which memory cell is to receive the data.Machine’s instructions categories机器语言指令类型：（ps 网上没有查到所谓的总线的类型，估计以下三个也就是了）Data Transfer(数据传输): copy data from one location to anotherArithmetic/Logic (算术逻辑指令) : use existing bit patterns to compute a new bit patterns Control (控制指令) : direct the execution of the programThe overall execution is controlled by two special-purpose registersProgram counter(程序计数器): address of next instructionInstruction register(指令寄存器): current instructionMachine Cycle机器周期the three-step process in which the conrel unit performs its job by continually repeating an guiding algorithm,including Fetch取值Decode解码Execute执行机器周期流程：首先在Fecth阶段，CPU的控制单元（control unit）根据程序计数器（program counter）所指的内存地址，把将要执行的指令从内存取过来存在指令寄存器（instruction register），然后让程序计数器指向储存下一个指令的地址；然后在Decode阶段，把指令寄存器里面的指令解码，知道指令的内容；最后在Execute阶段，根据指令内容执行。
指令内容执行完毕以后，机器周期重新有Fetch开始。
Chapter ThreeOpertating system 操作系统the softwate that controls the overall operation of a computer Functions of Operating Systems 操作系统的功能Oversee operation of computer管理计算机操作Store and retrieve files存取文件Schedule programs for execution调度可执行程序Coordinate the execution of programs协调程序的执行Evolution of Shared Computing分时计算的发展Batch processing批处理the execution of jobs by collecting them in a single batch,them executing them without further interaction with the userInteractive processing互动处理a program being executed to carry on a dialogue with the user through remote terminals.This requires real-time processing,which means the computer should perform the task quickly enough to keep up with activities in real world.Time-sharing分时the technique of dividing time into inervals and them restricting the execution of a job to only one interval at a tiomeMultitasking多任务(其实就是分时) the illusion of more than one task being performed simultaneously,implemented by MultiprogrammingMultiprocessor machines多处理器计算机Application software应用软件software consisting of programs for performing specific tasks for users.System software系统软件software performing those tasks that are common to computer systems in general,which means providing infrastructure(底层) for application software System software c onsists of operating system and utility software操作系统和实用软件Operating System Components 操作系统的组成Shell 壳:the portion of an operation system that handles the communicates with users,including text based & graphical user interface (GUI)Kernel 核心: the internal part performing basic required functionsFile manager文件管理Device drivers设备驱动Memory manager内存管理Additional components of kernel are scheduler and dispatcher调度程序和控制程序GUI graphical user interface 图形用户界面objects are represented pictorially,and user can issue commands by pointing and clickingDirectory (or Folder)文件夹 a bundle of filesDirectory Path(目录路径) a chain of directories within directoriesROM Read-Only Memory 只读内存Bootstrap引导程序: Program in ROMAutomatically run by the CPU when power is turned onTransfers operating system from mass storage to main memoryExecutes jump to operating systemProgram 程序:a series of coded software instructions to control the operation of a computer or other machineProcess 进程: The activity of executing a program执行一个程序的活动Process State 进程状态:Current status of the activity进程状态是在这一时刻机器的一个快照。