The Operating System

Question 1

Batch Operating Systems

Answer 1

Processes large amounts of data in batches

Question 2

How do batch operating systems work

Answer 2

Batch’s of data are sent to the CPU to be processed

Question 3

What is one advantage of batch operating systems

Answer 3

They are designed to handle large amounts of data at once quickly

Question 4

What is one disadvantage of batch operating systems

Answer 4

They have limited use with complex problems

Question 5

Single-user operating systems

Answer 5

Allows only one user to operate the system at any one time

Question 6

How do single user operating systems work

Answer 6

They limit the instructions that can be processed so that only one person can enter them

Question 7

What is one advantage and one disadvantage of Single-user OS

Answer 7

Advantage: Fast and efficient for problems encountered by one user.
Disadvantage: Not fast for dealing with large amounts of data, due to a lack of processing power

Question 8

Multi-user OS

Answer 8

Allows multiple users to access one operating system at the same time

Question 9

How do Multi-user OS work

Answer 9

Processes all of the users instructions and problems using more processing power, therefore making it more efficient

Question 10

What is one advantage and one disadvantage of Multi-user OS

Answer 10

Advantage: Can share data easily between multiple users
Disadvantage: Not suited to smaller tasks, as it wastes processing power

Question 11

Multi-tasking OS

Answer 11

Supports the ability to completed multiple tasks at the same time

Question 12

How do multi-tasking OS work

Answer 12

They Process multiple tasks at the same time on different cores.

Question 13

What is one advantage and one disadvantage of Multi-Tasking OS

Answer 13

Advantage: Allow the processing of multiple tasks
Disadvantage: is more expensive, and can loose smoothness if one operation slows the system down

Question 14

Multi-programming OS

Answer 14

Optimizes use of the CPU, preventing it from ever being idle

Question 15

How do Multi-programming OS work

Answer 15

Stores multiple jobs in the computers main memory at the same time, processing them each time the CPU is available

Question 16

What is one advantage and one disadvantage of Multi-Programming OS

Answer 16

Advantage: Makes processing smooth and feel like multiple programs are being processed at the same time
Disadvantage: Takes lots of memory, and can be slowed down by one large important task.

Question 17

Time sharing

Answer 17

Allows multiple users to share computers simultaneously

Question 18

Interrupts

Answer 18

A signal to the processor initiated by a program or device that temporarily stops the current processes to tell the processor to execute another task

Question 19

Processes

Answer 19

An instance of a program that is currently being executed, made of threads

Question 20

Threading

Answer 20

Each thread handles a separate sequence of tasks

Question 21

Multitasking

Answer 21

The appearance of multiple tasks being completed at the same time

Question 22

Shceduler

Answer 22

Decides which process will be executed next and the length of time that process will have to be executed for

Question 23

What are the three states in the scheduler

Answer 23

1. Ready to run
2. Running
3. Blocked

Question 24

Explain the state, Ready to run

Answer 24

Scheduler decides where the process will be placed within the ready to run queue

Question 25

Explain the state, Running

Answer 25

The process is within the CPU being Run

Question 26

Explain the state, Blocked

Answer 26

The process is waiting for an input/output operation for it to continue

Question 27

What are the five different Scheduling processes

Answer 27

1. First Come First Served
2. Shortest job first
3. Shortest time remaining
4. Round Robin
5. Multi-level feedback queues

Question 28

First come first serve

Answer 28

Processes are dispatched according to their arrival time on the ready queue

Question 29

First come first server, advantages and disadvantages

Answer 29

Simple to implement
Long processes can hog the CPU, Leading to a low throughput

Question 30

Shortest job first

Answer 30

Prioritizes the jobs that take the shortest amounts of time

Question 31

Shortest job first, advantages and disadvantages

Answer 31

Minimizes the average waiting time
Generates starvation, so can have extremely long turn around times

Question 32

Shortest remaining time

Answer 32

Prioritizes the process with the shortest amount of time left to execute

Question 33

shortest remaining time, advantages and disadvantages

Answer 33

Reduces the number of pre-emption’s
Fails, when the process time is unknown before hand

Question 34

Round Robin

Answer 34

Randomly selects the process that is next to be run from the list of processes

Question 35

Round Robin, advantages and disadvantages

Answer 35

Doesn’t face the issue of starvation
No priority for important tasks

Question 36

Multi-level feedback queues

Answer 36

Sorts the process into different queues with different priorities which it then takes from when available space is opened up in the CPU

Question 37

Multi-level feedback queues, advantages and disadvantages

Answer 37

Allows for process prioritization and aging
Requires a very complex algorithm to run