Chapter 1 - Operating Systems

Front 1

Operating Systems

Back 1

Software that controls the overall operation of a computer

Front 2

Job

Back 2

The unit of work that a computer operator gives to the operating system

Front 3

Batch processing

Back 3

The execution of jobs by collecting them in a single batch then executing them without further interaction with the user

Front 4

Job queue

Back 4

The jobs residing in mass storage waiting for execution in a batch processing system

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Queue

Back 5

A storage organization in which objects are ordered in first in first out fashion

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First in first out (FIFO)

Back 6

Objects are removed from the queue in the order in which they arrived

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Interactive processing

Back 7

This allows the program being executed to carry on a dialogue with the user through remote terminals

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Interactive processing

Back 8

This allows the program being executed to carry on a dialogue with the user through remote terminals

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Real time processing

Back 9

The computer performs the task in accordance with deadlines in it's external real world environment; seemingly instantaneously

Front 10

Timesharing

Back 10

A feature of an operating system that provides service to multiple users at the same time

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Multi programming

Back 11

Time is divided into intervals and then the execution of each job is restricted to only one interval at a time

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Multitasking

Back 12

The ability of one user to execute numerous tasks simultaneously

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Load balancing

Back 13

Dynamically allocating tasks to the various processors so that all processors are used efficiently

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Scaling

Back 14

Breaking tasks into a number of sub tasks compatible with the number of processors available

Front 15

Embedded systems

Back 15

Operating systems that focus on specific tasks such as handheld computers cell phones and medical devices

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Application software

Back 16

The programs for performing tasks particular to the machines utilization

Front 17

System software

Back 17

Performs those tasks that are common to computer systems in general

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Utility software

Back 18

Programs for performing activities that are fundamental to computer installations but not included in the operating system within the class of system software

Front 19

User interface

Back 19

The portion of an operating system that handles the communication between the computer and the user

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User interface

Back 20

The portion of an operating system that handles the communication between the computer and the user

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Shells

Back 21

Older user interface that communicates with users through textual messages using a keyboard and monitor screen

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Graphical user interface (GUI)

Back 22

Objects to be manipulated such as files and programs are represented pictorially on the display as icons

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Window manager

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Allocates blocks of space on the screen called windows and keeps track of which application is associated with each window

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Kernel

Back 24

Internal part of an operating system that contains those software components that perform the very basic functions required by the computer installation

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File manager

Back 25

Part of the kernel whose job is to coordinate the use of the machines mass storage facilities

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Directory or folder

Back 26

A bundle in which most file managers allow files to be grouped

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Directory path

Back 27

A chain of directories within directories often separated by slashes

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Device drivers

Back 28

Component of the kernel, software units that communicate with the controllers or at times directly with peripheral devices to carry out operations on the peripheral devices attached to the machine

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Memory manager

Back 29

Component of the kernel charged with the task of coordinating the machines use of main memory

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Paging

Back 30

Process through which the memory manager may create the illusion of additional memory space by rotating programs and data back-and-forth between main memory and mass storage

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Pages

Back 31

Uniformly sized units which are shuffled back-and-forth by the memory manager between main memory and mass storage

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Virtual memory

Back 32

A large fictional memory space created by paging

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Scheduler

Back 33

Component of the kernel that determines which activities are to be considered for execution

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Dispatcher

Back 34

Component of the kernel that controls the allocation of time for activities determined by the scheduler to be executed

Front 35

Boot strapping (booting)

Back 35

Procedure that is performed by a computer each time it is turned on

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Read only memory (ROM)

Back 36

A small portion of a computers main memory where the CPU expects to find its initial program; constructed from special non-volatile memory cells

Front 37

Boot loader

Back 37

The program that is initially executed when the machine is turned on stored in the machines ROM

Front 38

Booting

Back 38

The overall process of executing the boot loader and thus starting the operating system

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Firmware update

Back 39

The process in which the operating system and boot loader stored in ROM is updated

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Process

Back 40

The activity of executing a program under the control of the operating system

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Process state

Back 41

Associated with the process is the current status of the Activity

Front 42

Process table

Back 42

A block of information in main memory controlled by the scheduler that keeps track of all the processes

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Process Ready

Back 43

If a process is in a state in which it's progress can continue

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Process waiting

Back 44

If process progress is currently delayed until some external event occurs

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Time slice

Back 45

Short segments under which multi programming occurs typically measured in milliseconds are microseconds

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Process or context switch

Back 46

The procedure of changing from one process to another

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Interrupt

Back 47

A signal generated by the dispatcher that indicates the end of a time slice

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Interrupt handler

Back 48

A program that is part of the dispatcher that describes how the dispatcher should respond to the interrupt signal

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Test and set

Back 49

Instruction that directs the CPU to retrieve the value of a flag note the value received and then set the flag all within a single machine instruction

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Semaphore

Back 50

a variable or abstract data type used to control access to a common resource by multiple processes in a concurrent system such as a multiprogramming operating system

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Critical region

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A sequence of instructions that should be executed by only one process at a time

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Mutual exclusion

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The requirement that only one process at a time be allowed to execute a critical region

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Deadlock

Back 53

The condition in which two or more processes are blocked from progressing because each is waiting for a response that is allocated to another

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Forking

Back 54

When processes are allowed to create new processes to perform sub tasks and there is no space left in the process table and each process in the system must create an additional process before it can complete its task whereby no process can continue

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Kill

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Term to describe removing a process from the process table

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Spooling

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The technique of holding data in mass store for output to a shared resource at a later but more convenient time

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Login

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A sequence of transactions in which the user establishes initial contact with the computers operating system that controls access to the system

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Super user or administrator

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Person with highly privileged access to the operating system as identified during the login procedure

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Auditing software

Back 59

Software utilities that record and then analyze the activities taking place within the computer system

Front 60

Sniffing software

Back 60

Software that is left running on a computer recording activities and then later reporting them to a would be intruder

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Privilege levels

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Determines the ability of the CPU to execute particular sensitive instructions

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Privileged instructions

Back 62

Sensitive instructions that can only be executed while in privileged mode