计算机导论

1.If the memory cell whose address is 5 contains the value 8, what is the difference between writing the value 5

into cell number 6 and moving the contents of cell number 5 into cell number 6?

在第一种情况下，地址为6的存储单元结果包含值5；第二章情况下结果包含8

2.Suppose you want to interchange the values stored in memory cells 2 and

3.What is wrong with the following

sequence of steps: *

Step 1：Move the contents of cell number 2 to cell number 3.

Step2：Move the contents of cell number 3 to cell number 2.

Design a sequence of steps that correctly interchanges the contents of these cells.

Answer: 2->1; 3->2; 1->3;

3.What advantage does a hard-disk system gain from the fact that its disks spin faster than those in a floppy-disk

system?

有较快的数据检索速度和较高的传输速率。

4.In the ASCII code, what is the relationship between the codes for an uppercase letter and the same letter in

lowercase?

除了从低端数第6位对大写字母和小写字母分别是0和1外，两个位模式是相同的。

5.Convert each of the following binary representations to its equivalen ten form:

将下列二进制（binary representations）表示转换为等价的十进制（ten form）形式

6.Convert each of the following base ten representations to its equivale binary form:

将下列十进制（ten representations）表示转换为等价的二进制（binary form）形式

7.Convert each of the following two's complement representations to its equivalent base ten form:

将下列二进制补码（two's complement representations）转换成等价的十进制

8. a. Suppose you XOR the first two bits of a string of bits and then continue down the string by successively

XORing each result with the next bit in the string. How is your result related to the number of 1s appearing in the string?

b. How does this problem relate to determining what the appropriate parity bit should be when coding a

message?

Answer：

a、如果该串包含偶数个1，那么最后结果是0，否则是1；

b、结果是偶校验的校验位值

9.Which of the following would require real-time processing?

a)Printing mailing labels

b) b. Playing a computer game √

c) c. Displaying letters on a monitor screen as they are typed at the keyboard √

d) d. Executing a program that predicts the state of next year's economy

10.Identify examples of queues. In each case, indicate any situations that violate the FIFO structure.

实时处理是指一个程序的执行要与机器的环境里的活动相协调。

交互处理时指一个程序在其执行时人要与他交互。

成功的交互处理需要好的实时特征。’

11.What is the difference between time-sharing and multitasking

分时是在单处理器的机器上实现多任务的技术。

12.List the components of a typical operating system and summarize the role of each in a single phrase. *

（外壳）：与机器的环境通信

（文件管理程序）：协调机器大容量存储器的使用

（设备驱动程序）：处理与机器外部设备的通信

（存储管理程序）：协调机器主存储器的使用

调度程序：协调系统中的进程

调遣程序：协调各个进程的ＣＰＵ时间的分配

13.Summarize the difference between a program and a process. *

Program- a set of directions 指令的集合

Process-action of the following those directions 遵循这些指令的动作

14.In a time-sharing system, how can high-priority processes be allowed to run faster than others?

Dispacher 赋其高优先级--------或给该进程长的时间片