Computer Systems Architecture for Tutor Faith

Part I. Multiple-choice questions – 50 questions, 1 point each

1. An important difference between the I/O requirements of keyboards and disk drives is that

a. keyboard input is fast while disk drives are slow.

b. keyboards require constant monitoring, while disk drives do not.

c. disk drives have I/O controllers and keyboards do not have I/O controllers.

d. disk data is always transferred in blocks, never as individual bytes as with the keyboard.

2. The method of transferring data one word at a time from the CPU to a device is called

a. polling.

b. programmed I/O.

c. vectored interrupt.

d. direct memory access.

3. Since many interrupts exist to support I/O devices, most of the interrupt handling programs are also known as

a. device drivers.

b. device handlers.

c. peripheral handlers.

d. peripheral controllers.

4. Which of the following is not a function of how interrupts are used?

a. A completion signal

b. An abnormal event indicator

c. A means of allocating CPU time

d. A way of buffering large amounts of data

5. Events related to problems or special conditions within the computer system itself, like divide by zero, or attempting to execute a nonexistent op code, are called

a. irregular events.

b. unusual events.

c. abnormal events.

d. anomalous events.

6. Instructions that are intended for use by an operating system program, but not by an application program, are called

a. control instructions

b. limited instructions

c. prevalent instructions

d. privileged instructions

7. When the device generating the interrupt request identifies its address as part of the interrupt, it is called

a. polling interrupt.

b. discrete interrupt.

c. vectored interrupt.

d. monitoring interrupt.

8. Which of the following is not one of the three primary conditions for direct memory access to take place?

a. The I/O device must have an internal buffer.

b. There must be a method to connect together the I/O interface and memory.

c. There must be a means to avoid conflict between the CPU and the I/O controller.

d. The I/O controller associated with the particular device must be capable of reading and writing to memory.

9. Which of the following is not a common function of an I/O disk controller?

a. The I/O disk controller manages main memory during the transfer.

b. The I/O disk controller recognizes messages addressed to it and accepts commands from the CPU.

c. The I/O disk controller has interrupt capability, which it uses to notify the CPU when the transfer is complete.

d. The I/O disk controller provides a buffer where the data from memory can be held until it can be transferred to the disk.

10. Storage not immediately available to the CPU is referred to as

a. cloud storage.

b. off-line storage.

c. network storage.

d. secondary storage.

11. In a disk drive where the drive motor turns at constant angular velocity, which is true of the linear velocity?

a. inner tracks move the fastest

b. outer racks move the fastest

c. middle tracks move the fastest

d. all tracks move at the same speed

12. In a mirrored array with 4 disks, each of the disks stores exactly the same data. The access time for a multiblock read is reduced by a factor of about ______.

a. two

b. four

c. eight

d. sixteen

13. The technique used for storage and retrieval in an LTO formatted data cartridge is called

a. a) data torrent.

b. b) LTO tasking.

c. c) data continuity.

d. d) data streaming.

14. Displays that use 256 (Red) × 256 (Green) × 256 (Blue) different colors on the screen is sometimes described as a

a. true color system.

b. virtual color system.

c. ultra high density system.

d. high density color system.

15. An International standard maintained by a non-profit consortium to render 2-D and 3-D objects is known as

a. OpenGL.

b. DirectX.

c. ActiveX.

d. OpenSource.

16. Which display technology consists of a thin display panel that contains red, green, and blue LEDs for each pixel with transistors for each LED that generate electrical current to light the LED?

a. CRT

b. LCD

c. FED


17. When a key is pressed on the keyboard, a binary code called a(n) ______ is sent to the controller.

a. octal code

b. scan code

c. check code

d. ASCII code

18. Protocols that describe a computer’s communication with the physical layer network are called

a. LAN access control protocols

b. shared access control protocols

c. medium access control protocols

d. medium admission control protocols

19. Which of the following use computer-based operating systems?

a. Mobile phones

b. Business systems

c. E-readers and notebooks

d. All of the above

20. Most modern operating systems provide some capability for combining computer commands into pseudo-programs, commonly called

a. API scripts.

b. shell scripts.

c. power scripts.

d. internal scripts.

21. Which operating system function is responsible for providing a consistent view of files across different I/O devices?

a. Memory management

b. The file management system

c. The input/output control system

d. Network management, communication support, and communication interfaces

22. Which operating system function optimizes the completion of I/O tasks by using algorithms that may reorder the requests for efficient disk access?

a. Scheduling and dispatching

b. Secondary storage management

c. Support for system administration

d. System protection management and security

23. Which operating system function limits the execution of a process to a sandbox?

a. Scheduling and dispatching

b. Secondary storage management

c. Support for system administration

d. System protection management and security

24. Which operating system function manages system configuration and setting group configuration policies?

a. Scheduling and dispatching

b. Secondary storage management

c. Support for system administration

d. System protection management and security

25. The CPU may be switched rapidly between different programs, executing several instructions from each, using a periodic clock-generated interrupt. What is that technique called?

a. threading

b. time-slicing

c. execution switching

d. nonpreemptive switching

26. The operating system configuration of UNIX is an example of a

a. layered configuration.

b. monolithic configuration.

c. hierarchical configuration.

d. microkernel configuration.

Section 15.4 Organization

27. The predominant operating system type in current use are _____________ multitasking systems.

a. mobile

b. real-time

c. embedded

d. single user

Section 15.5 Types of Computer Systems

28. Command languages are also referred to as

a. APIs.

b. procedures.

c. scripting languages.

d. all of the above.

Section 16.1 Purpose of the User Interface

29. Some systems hide the user interface and use a _____________ model to serve as the interface for applications.

a. CLI

b. GUI

c. Web browser

d. Powershell Window

Section 16.1 Purpose of the User Interface

30. Which user service is responsible for handling the physical manipulation of the files and to translate between logical and physical file representations?

a. File Management System

b. Disk and other I/O Device

c. Security and Data Integrity Protection

d. System Status Information and User Administration

Section 16.2 User Functions and Program Services

31. Which user service is responsible for determining the amount of available disk space?

a. File Management System

b. Disk and other I/O Device Services

c. Security and Data Integrity Protection

d. System Status Information and User Administration

Section 16.2 User Functions and Program Services

32. Which user service allows the user to change the user’s password?

a. Program Execution

b. File Management System

c. Security and Data Integrity Protection

d. System Status Information and User Administration

Section 16.2 User Functions and Program Services

33. Keyword operands are sometimes known as

a. switches.

b. mutations.

c. amendments.

d. command list parameters.

34. Which type of program is well suited for routine transaction processing applications, such as credit card billing and payroll?

a. Batch programs

b. Network programs

c. Complier programs

d. Interactive programs

35. Early implementation of gesture- and voice-based technology was designed primarily for

a. thin clients.

b. set-top boxes.

c. computer games.

d. high-end workstations.

36. Which of the following is NOT an important feature of a command language?

a. Branch and loop

b. Print messages on the screen

c. Notifying the system administrator

d. Assign and change the value of a variable

37. Assigning system resources such as memory through _____________ assures that a program cannot overwrite memory in use by a different program.

a. the API

b. powershell

c. a script program

d. a command shell

38. Which of the following is a portable script language?

a. C#

b. Python

c. Java

d. XML

39. What type of data file consists of information about other files?

a. Video

b. Database

c. Directory

d. Source code

40. The _______________ is the smallest unit that the file management system can store or retrieve in a single read or write operation.

a. sector

b. chunk

c. cluster

d. byte

41. If the allocation unit size is too small,

a. file access is slower.

b. there is less overhead to track each allocation unit.

c. there is more unused space at the end of most allocation units.

d. All of the above

42. Most user commands to the operating system are actually requests to the ________ manager.

a. I/O

b. file

c. memory

d. processor

43. A ____________ occurs when two different records calculate to the same hash number (logical record number).

a. crash

b. impact

c. conflict

d. collision

44. The Universal Data Format (UDF) supports High Definition and Blu-Ray DVD formats. UDF directory format is ______________.

a. flat

b. ad hoc

c. matrix

d. hierarchical

45. The file system must maintain a directory structure for each device. In most cases, the directory for each device is stored on the device itself. In many computer systems, each file system is called a

a. disk.

b. volume.

c. directory.

d. partition.

46. To increase security, the critical parts of the operating system will execute in a protected mode while other programs will execute in _______________ mode.

a. user

b. global

c. shared

d. isolated

47. _____________ systems will limit the time that the program remains in the running state to a fixed length of time corresponding to one or more quanta.

a. Multiuser

b. Preemptive

c. Cooperating

d. Nonpreemptive

48. When memory is partitioned into fixed spaces, ____________ fragmentation is likely to occur.

a. a) outer

b. b) central

c. c) internal

d. d) external

49. During execution, programs exhibit a tendency to stay within small areas of memory during any given period of time. This property is called the

a. locality of reference.

b. small area of execution.

c. residual execution property.

d. neighboring instruction concept.

50. Application program interface services allow a program to access network services. Some network operating systems also provide access to services on remote machines that might not be available locally. These services are called

a. server-client calls (SCCs).

b. object procedure calls (OPCs).

c. remote procedure calls (RPCs).

d. network method calls (NMCs).

Part II. Essay questions – 10 questions, 5 points each, 50 points all together

Answer the questions succinctly and clearly, explain your answer, and show your work. Answers, even if right but without an explanation, will get no credit. On the other hand, partial credit will be given for the right steps shown to solve a problem, even the final result is not correct. The explanations need to be brief, but complete, logical, and to the point. Do not quote anybody else; use your own words and calculations.

1. Suppose that the keyboard device stored keystrokes in a buffer until it was full then sent the entire buffer for processing. What would be some adverse consequences? (Two or three sentences should be adequate to answer this question)

2. Consider the steps required to write a block of data from a disk to memory. Outline the major sequence of I/O events that must occur to make this possible. (There are three major steps)

3. How is an arithmetic overflow error or divide by zero error interrupt different than an interrupt from the hard disk controller signaling that a data transfer has completed? (Three or four sentences are sufficient)

4. Suppose that all programs in a particular CPU are given 50 clock cycles to process before getting swapped out for another program. Suppose also, that it takes 5 CPU clock cycles to swap out the process control block (PCB) for a particular program and restore the next program’s PCB. What percent of the CPU clock cycles are used for processing 100 programs? (Hint: calculate: Program clock cycles / (Swap clock cycles + Program clock cycles)). Show your work and how you arrived at the solution.

5. For a display of 1920 pixels by 1080 pixels at 16 bits per pixel how much memory, in megabytes, is needed to store the image?

6. What is the average rotational latency of a hard drive rotating at 7,200 RPM or 120 revolutions per second? (Give your answer in milliseconds)

7. Answer both part a and b.

a. What is the responsibility of the dispatcher during a context-switch?

b. There are two levels of scheduling. One level of scheduling determines which jobs will be admitted to the system and in what order. What does the other level of scheduling do?

8. There are many obvious advantages of a Graphical User Interface (GUI). But what are some disadvantages of a GUI?

9. How many 512 byte blocks are required to store a 1.6MB file?

10. Perform the Round-Robin dispatch algorithm, with time quantum equal to 300 milliseconds, on the job queue and calculate:

Job 1 arrives at time 0 and needs 500 milliseconds to complete.

Job 2 arrives at time 300 milliseconds and needs 400 milliseconds to complete.

Job 3 arrives at time 400 milliseconds and needs 200 milliseconds to complete.

Job 4 arrives at time 400 milliseconds and needs 500 milliseconds to complete.

a. The average wait time. (Hint: average the number milliseconds each job was in a wait state)

b. Average turn-around-time. (Hint: for each job, count the number of milliseconds from arrival to completion and average)

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