Ch 2: Operating System Overview

Question 1

Describe the Instruction set architecture (ISA).

Answer 1

It is a part of the abstract model of a computer that defines how the CPU is controlled by the software.

Question 2

Describe the Application binary interface (ABI).

Answer 2

It defines the system call interface for the OS and the hardware resources and services available through ISA.

Question 3

Describe the Application programming interface (API).

Answer 3

It gives a program access to the hardware resources and services available in a system through ISA with library calls.

Question 4

Describe job control language (JCL).

Answer 4

It is used to provide instructions to the monitor.

Question 5

There are two Modes of Operation. What are they? Describe them.

Answer 5

1. User Mode - certain areas of memory are protected from user access; certain instructions may not be executed
2. Kernel Mode - privileged instructions may be executed; protected areas of memory may be accessed

Question 6

Define uniprogramming.

Answer 6

One program sits in the main memory at a time. Only a single task or program is in the RAM at a particular time.

Question 7

Define multiprogramming.

Answer 7

The memory is expanded to hold three, four, or more programs and switch among all of them.

Question 8

Define process.

Answer 8

A unit of activity characterized by a single sequential thread of execution, a current state, and an associated set of system resources.

Question 9

What are the three components of a process?

Answer 9

1. An executable program
2. The associated data needed by the program (variables, work space, buffers)
3. The execution context (process state) of the program

Question 10

Define paging.

Answer 10

It is a memory management scheme that eliminates the need for contiguous allocation of physical memory. It permits the physical address space of a process to be non-contiguous.

Question 11

Describe microkernel architecture.

Answer 11

It assigns only a few essential to the kernel: address spaces, IPC, and basic scheduling.

Question 12

Describe multithreading.

Answer 12

It is the technique in which a process, executing an application, is divided into threads that can run concurrently.

Question 13

What are the advantages of SMP (Symmetric Multiprocessors)?

Answer 13

Performance, Scaling, Availability, and Incremental Growth