chapter 4 system software. software programs that tell a computer what to do and how to do it. sets...
TRANSCRIPT
Chapter 4System Software
Software
Programs that tell a computer what to do and how to do it.
Sets of instructions telling computers to perform actions in a certain order.
Programs
The Two MainCategories of Software
Application Software
System Software
System Software
System software includes programs that manage the basic operations of a computer such as starting up and saving and printing files.
Application Software
Application software includes programs that perform a single task such as spreadsheet analysis.
Operating System
• manages main memory, or RAM• controls and configures peripheral devices• formats and copies disks• manages essential file operations• monitors system performance• provides a user interface.
How A Computer Boots Up
RAM
Windows loads portions of code into all three areas of RAM on startup.
Software User Interfaces
All software, including operating systems, must have a user interface to allow communication between the software and the user. The interface controls the manner in which data and commands are entered and the way information and processing options are presented on the screen.
Two Types of User Interfaces
Command-line interfaces
Graphical user interfaces (GUIs)
Command-line interfaces
Designed to accept commands from the user in the form of lines of text code. The DOS operating system has a command-line interface.
Graphical UserInterfaces (GUIs)
Accept user commands in the form of mouse clicks on icons or menu items.
Graphical UserInterfaces (GUIs)
• Common command icons
• On-screen desktop
• Display windows
• Key feature option menus
• Dialog boxes
• Online Help
PC Operating Systems
Microsoft Windows
Novell NetWare
Macintosh, UNIX, and OS/2
Microsoft Windows
• Developed in 1985• Increasingly has dominated PC
market • Most recent version: Windows XP• Has required more powerful
microprocessors and more disk space with each release (software driving hardware)
• Under development: Windows Longhorn (working name)
Microsoft Windows
Clicking the Start button in Windows XP displays a menu of options, including:
• My Documents• My Recent Documents• My Computer• My Network Places• Help and Support• Search• Run• Log Off• Shut Down• And others. . .
Microsoft Windows
Windows and other GUIs allow users to work with multiple applications at the same time.
Novell NetWare
Novell NetWare is a popular and widely used operating system for microcomputer-based local area networks.
UNIX
• Uses a complex command- line interface• Offers simultaneous access by many users to a single powerful computer• Cross-platform operating system
UNIX was the first language of the Internet.
Macintosh
The Mac OS was the first commercial GUI, serving as a model for the Windows GUI that followed. Long a favorite of graphic artists and designers, the Mac OS only runs on Apple Macintosh computers.
Macintosh OSX
Its newest version, Mac OS X, includes a new interface called Aqua and is based on the UNIX operating system.
OS/2 Operating Systems
IBM’s OS/2 GUI operating system was developed to compete with Microsoft Windows and the Apple Mac OS. The latest version, OS/2Warp, can run programs written for both DOS and Windows systems. A network server version also has been developed.
Server Operating Systems
Windows NT Server
Windows 2000 Server
Windows Server 2003
UNIX
Linux Netware 6
Wireless DeviceOperating Systems
Palm OS Windows CE Pocket PC
Microsoft’s .NET Initiative
– The .NET Initiative incorporates applications and a suite of tools
and services that operate over
the Internet, using XML.– Users will rent applications
over the Internet and will be
able to integrate fax, e-mail,
and phone services.
– The Internet will house all of a user’s data.
Utilities
A utility program performs a single maintenance or repair task.
Utilities
• Virus checkers• Diagnostic utilities• Uninstallers• Disk scanners• Disk defragmenters• File compression
utilities• Backup utilities• Disk toolkits• Spam blockers
Language Translators
Convert high-level program languages into machine language so the computer can run the program.
Types of LanguageTranslators
Compilers
Interpreters
Compilers
Compilers translate an entire program at once
Interpreters
Interpreters act on just one line of instruction at a time.
On the Horizon
USER-FRIENDLY SYSTEM SOFTWARE
In the future, system software users may be able to click on wizard icons to automatically perform tasks such as formatting disks or copying files.
IMPROVED UTILITIES SOFTWARESuites containing all needed utilities, including antivirus programs, a firewall that automatically blocks Internet hackers, and programs that can identify hacker locations.
NEW USER INTERFACE DESIGN FOR OPERATING SYSTEMSOperating systems for the PC are evolving in an “all-in-one” direction.
LINUX: AN OPEN-SOURCE CHALLENGE TO WINDOWS?Fans of Linux praise its stability, flexibility, and generally low cost (vendors usually package it with various tools; hence there is a charge).