计算机专业英语(霍洪涛)课件Chapter 4

谢谢 * Chapter 4 Operating System Review 前驱，前任 后继，继任 常见的 足够的 有时；在某种情况下 不局限于 目录，存货清单 支付、支出 伪码 * predecessor successor commonplace not limited to inventory disburse pseudocode under certain circumstance sufficient Unit 1 Operating System Structure Writing programs that keep track of all these components and use them correctly, let alone optimally, is an extremely difficult job.(P68P2L4) 写一个能跟踪所有组成部分、正确地使用它们的程序是一项极其困难的工作，更不用说对其进行优化了。 句子分析: 主干 从句 keep track of 跟踪 let alone 更不用说/不干涉，不打扰，不管 Let him alone. He needs a rest. 别去打扰他，他需要休息一下。 * Writing programs is an extremely difficult job. … programs that keep track of … Unit 1 Operating System Structure lump(P68L1) n. 块；肿块 a lump of… 一块。。。 I noticed a lump in her skin. 我注意到她皮肤上有个肿块 a lump in the throat 如鲠在喉 earn its keep(P68L3) In each case, retailers will carry only content that can generate sufficient demand to earn its keep.在这些行业里，商家的进货必须要保证有足够的销量，才能勉强为生。 * 勉强为生 The Structure of A Computer System Unit 1 Operating System Structure * Unit 1 Operating System Structure At the bottom is the hardware, which in many cases is itself composed of two or more layers. The lowest layer contains physical devices(p68RP2L1). 在最下面的是硬件，很多情况下都是由两个以上层次组成。最底层含有物理设备。 Next comes a layer of primitive software, called microprogram, that directly controls these devices and provides a cleaner interface to the next layer(p68RP1L1). 接下来的一层是简单的软件，叫做微程序，用来直接控制设备，并且为下一层提供更为干净的界面。 * Unit 1 Operating System Structure In machine language layer, the input/output devices are controlled by loading values into special device registers(p69P1L2). 在机器语言层，输入/输出设备被控制着把值放入到特殊的设备寄存器中。 A major function of the operating system is to hide all this complexity and give the programmer a more convenient set of instructions to work with(p69P2L1). 操作系统的重要功能就是隐藏所有这些复杂的事物，给程序员使用一组更方便的指令工作。 * Unit 1 Operating System Structure On the top of the operating system is the rest of the system software(p69RP1L1).