Chapter 5- System Software: The Operating System, Utility Programs, and File Management

OS Uses a device driver

- small utility program that enables communication between OS and device --If there is an error with a device, it is generally a driver problem

OS Coordinates applications...

1. OS keeps track of all installed software Allows user to un-install software 2.Allows a way to launch, close, switch between applications 3. Gives each application access to the CPU using computer code

Operating System coordinates...

ALL activity on computer

platform

Combination of CPU and OS ----32 bit processors under OSX

Role of the Operating System:

Manage computer hardware Coordinates tasks, use of CPU, Memory and Storage Provides a way for application software to work with the CPU Provides a User Interface

CPU- dependent -

Most OS- designed to take advantage of a particular CPU

Characteristics of Operating Systems:

Multi-tasking - more than one process at a time Multi-user - more than one user at a time Proprietary or Open Source - Real Time - for embedded systems

RAM is limited in Capacity ( < 12GB typically)

OS must control the allocation of RAM to ensure there is enough space for all active processes And clear out items from RAM when no longer needed

2 primary types of System software

Operating System (OS) like Windows, OSX, Linux on PCs Android, iOS, Windows Mobile on smartphones / mobile devices Utility Programs - like device drivers, file compression, backup programs, ...

GUI = Graphical User Interface

Provides graphics (icons, clickable objects, tiles) that can be selected using a mouse or finger

OS uses ? for temporary workspace

RAM as its temporary workspace All active data and instructions are held in RAM temporarily

Why "shut down and re-start" works if computer is "frozen"

Ram clears when you shut down computer

Examples of OS Utilities:

System Restore, Backup, Disk Cleanup, File Recovery, CD tools Task Manager, Resource Manager, Accessibility Tools Anti-virus and security programs File compression - such as WinZip or RAR - make large files more compact without losing any detail ***Computer literate individual should be able to work with ZIP files and key utilities - including Task Manager

OS must manage and communicate with every device attached to the computer

True

True/False: CPU is only component capable of "processing

True

OS must respond to user "interrupts"

User types a key, clicks a mouse, issues a command OS must respond - immediately - to user! OS arranges execution of all activities in a systematic way --input devices interrupt the process that OS responds to

Proprietary or Open Source -

Windows, OSX, Android are proprietary (company-owned) LINUX is open source

"virtual memory"

a process to "borrow" some space on disk to store items from memory Works, but not very efficient - "thrashing"- a lot of movement of data- slows down computer --"swap out" data from RAM onto hard drive

Utilities -

a type of system software; small programs that also control hardware, perform house-keeping tasks for the computer

Task Manager -

a way to view active programs/processes

Code =

actual instructions computer can follow

Operating systems are dependent on

architecture of CPU

File -

collection of data stored and treated as a single unit

User Interface -

design of the screen/menus/icons that allow you to interact with the computer

Multi-tasking -

more than one process at a time

Multi-user

more than one user at a time For networks: LINUX, UNIX, Windows Server LINUX & UNIX also for supercomputers and mainframes

When multi-tasking, CPU must be

must be shared by all active processes: OS must assign a "slice of CPU time" to each active process Switch between them, millions of times per second

Real Time

near-immediate response Such as in cars, TV sky cameras, medical equipment, etc.

Folder -

organized collection of files

Application software is

platform-dependent

System Software

programs that actually run the computer and coordinate computer activity

What if you run out of room in RAM?

swap out" data from RAM onto hard drive Called "virtual memory"

File path -

text that defines the location of a file, e.g. C:\Documents\COSC100\Lab1.docx **Computer-literate individuals should be able to read a file path and manage location of their files!**

OS includes a File Manager component

to allow organized access to all files, folders, and programs in storage

OS Uses a Device Manager

to identify and manage every device and peripheral **OS knows location, properties, capabilities of each device