Week 1

Question 1

What is an operating system?

Answer 1

An operating system is software that:
- Provides a basis for application programs
- Acts as an intermediary between the user and the hardware
(1)

Question 2

What are the three main responsibilities of an operating system?

Answer 2

• Memory management
• Storage, I/O, file management
• Process management
  (Week 1 lecture 1)

Question 3

What are the four components of a computer system?

Answer 3

1. Hardware
2. Operating system
3. Application programs
4. User
   (1.1)

Question 4

What is the role of hardware in a computer system?

Answer 4

Hardware provides basic computing resources for the system
(1.1)

Question 5

What is the role of application programs in a computer system?

Answer 5

Application programs define ways that resources are used to solve users’ computing problems
(1.1)

Question 6

What is the role of an operating system in a computer system?

Answer 6

An operating system controls hardware and coordinates its use among the various application programs for users
(1.1)

Question 7

What three “elements” form a computer system?

Answer 7

1. Hardware
2. Software
3. Data
   (1.1)

Question 8

True or False?
An operating system is useless by itself.

Answer 8

True
An operating system provides an environment where other programs can do useful work. (1.1)

Question 9

What is the goal of an operating system for a user?

Answer 9

An operating system provides ease of use, with some performance and security. Resource utilization is not a point of focus for the user. (1.1.1)

Question 10

Where does the operating system sit in an abstraction of a computer system?

Answer 10

User
Application programs
Operating system
Hardware
(1.1.1)

Question 11

What is the goal of an operating system for the system?

Answer 11

From the computer’s point of view, the operating system is most involved with the hardware. The operating system manages resources and how to best allocate them to programs and users to maximize efficiency. (1.1.2)

Question 12

What is a control program?

Answer 12

A control program manages the execution of user programs to prevent errors and improper use of the computer, especially with the operation of I/O devices. (1.1.2)

Question 13

True or false?
A control program is an example of an operating system.

Answer 13

False
An operating system is a control program. (1.1.2)

Question 14

What is Moore’s Law?

Answer 14

Proposed in the 1960’s, Moore’s Law predicted that the number of transistors on an integrated circuit would double every 18 months. (1.1.3)

Question 15

What is the fundamental goal of computer systems?

Answer 15

Computer systems execute programs and make solving user problems easier. (1.1.3)

Question 16

What is a kernel?

Answer 16

A kernel is another name for operating system, and is one program what is running at all times on the computer. (1.1.3)

Question 17

What is a system program?

Answer 17

System programs are associated with the operating system but are not part of the kernel (1.1.3)

Question 18

What is an application program?

Answer 18

An application program is any program that is not associated with the operation of the system (1.1.3)

Question 19

What is middleware?

Answer 19

Middleware is a set of software frameworks that provide additional services to application developers (1.1.3)

Question 20

What is a device driver?

Answer 20

A device driver understands the device controller and provides the rest of the operating system with a uniform interface to the device (1.2)

Question 21

True or false?
The CPU and device controllers can execute in parallel.

Answer 21

True
A memory controller synchronizes access to the memory.

Question 22

What are interrupts?

Answer 22

An interrupt is an event that is triggered at any time by sending a signal to the CPU via a system bus

Question 23

What functions are common in an interrupt?

Answer 23

The interrupt must:
- Transfer control to the appropriate interrupt service routine
- Invoke a generic routine to examine the interrupt information
- Call the interrupt-specific handler

Question 24

What kind of storage is used to store pointers to interrupt routines?

Answer 24

A table of pointers to the memory addresses of the interrupt routines is used.
This table is commonly stored in low memory (towards the beginning of the memory)

Question 25

What is used to index the table of pointers to provide the address of the interrupt service routine for the interrupting device?

Answer 25

An interrupt vector is used.

Question 26

True or false?
The state of the system before the interruption does not need to be saved.

Answer 26

False
The interrupt architecture must save the state information of whatever was interrupted, so that it can restore this information after servicing the interrupt.
If the interrupt routine needs to modify the processor state, it must save the current state and then restore that state before returning.