Operating Systems

Question 1

What are two common features of a Batch operating system?

Answer 1

1) Processes all jobs in one go with no user interaction required after starting.
2) Makes the most of CPU utilisation, as runs when processor is not busy (weekends etc.)

Question 2

What are the behaviours of a Single User operating system, and what are they normally used for?

Answer 2

1) Single person, single user program in main memory.

2) Embedded Computers, display boards etc.

Question 3

What is the difference between a Multi-programming, Multi-Tasking and a Multi-User (Multi-Access) operating system? What is a similarity between them?

Answer 3

Multi-Programming: Multiple programs in main memory at the same time.

Multi-Tasking: Same as Multi-Programming, but specifically on a single, standalone computer.

Multi-User/Multi-Access: Several users can interact at the same time! Multi-Programming but with multiple terminals. It’s softXpand!

Similarity: All use schedulers (Time Slicing)

Question 4

What is buffering? Give 3 examples of what it could be used for.

Answer 4

Allows data to be transferred between devices at their optimum speed and capacity.

Examples:

1) Printer and Camera
2) Keyboard inputs
3) Disc buffer (Holds blocks of data ready to be saved and receives records being loaded).

Question 5

What is double buffering, explain why it is needed and describe an advantage of double buffering.

Answer 5

1) Data can only be read or written to a buffer at any given time.
2) Two buffers are used, which improves the time lost by a device having to stop while waiting for data.

Advantage: Speeds up data transfer, as it reduces the time each device has to wait before it can transmit/receive more data.

Question 6

Give an example of a use of Double Buffering.

Answer 6

Video and audio streaming.

Question 7

Memory Partitioning?????

Answer 7

Find what goes here…

Question 8

Describe two possible ambiguity problems with using speech recognition as an input method.

Answer 8

Difficult to determine difference between words that sound the same (homophones), e.g “Their” and “There”.

Command words may be interpreted as input (dictated) words, or vice versa. For example saying “Stop Dictation” may just type “Stop Dictation”, instead of actually registering to stop the dictation process.

NOT: Ambiguity is not caused by accent, cold, loud environment.