1.What is the purpose of the command interpreter?

		It reads commands from the user or from a file of commands and executes them.
		It provides packet ordering and data correction over the network.
		It provides error detection that occurs in the codes.
		It manages the programs by finding the bugs and correcting them.

2.

What are the two disadvantages of the layered approach?

		Poor performance due to the overhead of traversing through the layers.
		Good performance due to the efficient traversing through the layers.
		The system is easier to debug and modify. The system is harder to debug and modify

3.

What is the purpose of system calls?

		System calls allow user-level processes to request services of the operating system.
		System calls provide error detection that occurs at both the hardware and software levels.
		System calls provide packet ordering and data correction over the network.
		System calls manage disk physical damages, so the programs know which parts are functioning properly.

4.

What are the two main advantages of the layered approach to system design?

		The system is easier to debug and modify because changes affect only limited sections of the system.
		The data is better encrypted and more secure.
		Information is kept only where it is needed and is accessible only within a defined and restricted area.
		Good performance due to the efficient traversing through the layers.

5.

Match the services provided by an operating system, and the explanation of the conveniences they provide.

	Program execution
	I/O operations
	File-system manipulation
	Communications
	Error detection

A.	Inspects data for the corruption during the transfers and inspects media to check for data consistency.
B.	Provides disk space used for data and programs.
C.	Converts messages into packets, that are sent to network controller, transmitted, and reassembled at the destination.
D.	Provides communication with disks, tapes, and other devices.
E.	Loads the contents of a file into memory and begins its execution.

6.

What is the purpose of system programs?

		They provide functionality to users so that users do not need to write their own programs to solve problems.
		They provide error detection that occurs in the codes.
		They manage the programs by finding the bugs and correcting them.
		They provide packet ordering and data correction over the network.

(attempt All)