Yuh-Jzer JoungSystems Software The Power Behind the power

Yuh-Jzer Joung Systems Software

Systems SoftwareThe Power Behind the power


User

Applications Softwareword processing, spreadsheet, communications, database, etc.

External utility program

Systems softwareOperating System

Language translators

Hardware (computer plus peripheral devices)


The Operating System

The operating system consists of the master system of programs that manage the basic operations of the computer.

• Booting• Housekeeping tasks• User interface• Managing computer resources• Managing files• Managing tasks


Operating System vs. Operating Environment

An operating environment is a user interface built on top of an operating system. It is often a graphical user interface or a menu-driven interface. E.g., Windows 3.1 on top of DOS.

Hardware


Booting

The operating system begins to operate as soon as you turn on, or “boot,” the computer. The term booting refers to the process of loading an operating system into computer’s main memory from diskette or hard disk.

Housekeeping Tasks

Perform common repetitious “housekeeping tasks” such as formatting a diskette.

User Interface

The user interface is the part of the operating system that allows you to communicate, or interact, with it.


C:\>VER

MS-DOS Version 6.22

C:\>_

File Edit View Layout Tool

Open… Shft+F10

Close…

Save… Ctrl+F12

Save As... F10

(C:) (D:) (E:)

• Command-driven: requires you to enter a command by typing in codes or words.

• Menu-driven: allows you to choose a command from a menu.

• Graphical: the graphical user interface (GUI) uses images to represent options. Icons are small pictorial figures that represent tasks, functions, or programs.

User Interface


Friendly interfaces

Some microcomputer makers provide interface software that uses familiar objects or cartoon characters in order to make systems software easy for novices to use .


Managing Computer Resources

Behind the user interface, the operating system acts like a police officer directing traffic. This activity is performed by the supervisor, or kernel, the central component of the operating system. The supervisor, which manages the CPU, resides in main memory while the computer is on and directs other programs to perform tasks to support applications programs.

Managing Tasks

Among the ways operating systems manage tasks in order to run more efficiently are multitasking, multiprogramming, time -sharing, and multiprocessing.


Managing Tasks

• Multitasking: executing more than one program concurrently.• Multiprogramming: concurrent execution of different users’ programs.• Time-sharing: round-robin processing of programs for several users.

The key to time-sharing is time slicing.• Multiprocessing: simultaneous processing of two or more programs

by multiple computers. Two approaches: --- co-processing --- parallel processing.


Microcomputer Operating Systems & Operating Environments

• DOS• Macintosh System 7.X• Windows 3.X for DOS• OS/2 Warp• Windows 95/98

• Windows NT• Unix• NetWare• Coming attractions


DOS-for Disk Operating System-runs primarily on

IBM and IBM-compatible microcomputers

Microsoft’s MS-DOS: The”MS” stands for Microsoft. Microsoft launched its original version, MS-DOS 1.0, in 1981 and there have been several upgrades since then.

IBM’s PC-DOS: The”PC” stands for Personal Computer. The most recent version is PC-DOS 7, released March 1995.


For the love of Mac

The icons, pull-down menus, and windows of the Apple Macintosh System 7 operating system give the Mac a look and feel that makes many users say they love their machines.


Windows for DOSWindows is an operating environment made by Microsoft that lays a graphical user interface shell around the MS-DOS or PC-DOS operating system .


Windows 95 & Later

Windows 95, the successor to Windows 3.1 for DOS, is a true operating system for IBM-style personal computers rather just an operating environment .

• Clean “start”• Better menus• Long file names• The “Recycle Bin” • 32-bit instead of 16-bit• Plug and play (PnP)


Windows NT

• Unveiled by Microsoft in May 1993, Windows NT, for New Technology, is an operating system intended to support large networks of computers.

• Primary designed to run on the more powerful microprocessors, both Intel’s Pentium and Motorola’s PowerPC.

• Use client/server architecture.


Unix

• Developed at AT&T Bell Lab in the 1960s. AT&T then has licensed Unix to many Universities and companies, producing several versions of Unix.

• Unix is an operating system for multiple users and has built-in networking capability, the ability to run multiple tasks at one time and versions that can run on all kinds of computers.

• Is “portable” because it can run with relatively simple modifications on different types of computers.

• Recent versions, BSD4.1.3, Solaris, Linux, FreeBSD, ...


NetWare

• Developed by Novell during the 1980s, NetWare has become the most popular operating system for coordinating microcomputer-based local area network (LAN) throughout a company or campus.

• Allows remote disks to be accessed as local disk (like C:\>, D:\>, F:\> ).

• Microsoft is trying to beat NetWare with its Windows NT.


Operating Types of Single System Microprocessors User Multitask Multiuser

MS-DOS Intel 8088,8086, Yes PC-DOS 80286,80386 80486,Pentium Macintosh Motorola 8030, Yes Yes System 8040,68030, Software 68040,PowerPC Windows3.1 Intel 80286,80386, Yes Yes Yes 80486,Pentium OS/2 Intel 80286,80386, Yes Yes Yes 80486,Pentium, PowerPC Windows95 Intel 80386,80486, Yes Yes Yes Pentium WindowsNT Intel 80386,80486, Yes Yes Pentium,PowerPC, DEC Alpha RISC Unix Almost all processors Yes Yes NetWare Intel 80386,80486, Yes Yes Pentium


External utility programs are special programs that provide specific useful services not performed or performed less well by other systems software programs. Examples include:

• Screen saver• Data recovery• Backup• Virus protection• File defragmentation• Data compression• Memory management

External Utility Programs


• Virus protection: A virus consists of hidden programming instructions that are buried within an applications or systems program. They copy themselves to other programs, causing havoc. Fortunately , anti-virus software is a utility program that scans hard disks, diskettes, and the microcomputer’s memory to detect viruses.

• File defragmentation: Fragmentation is the scattering of portions of files about disk in non-adjacent areas, thus greatly slowing acess to the files.

• Memory management : Memory-management utilities are programs that determine how to efficiently control and allocate memory resources. They may be activated by software drivers. A driver is a series of program instructions that standardizes the format of data transmitted between a computer and a peripheral device .


User’s responsibility: Purchasing, installing, upgrading, using

Personalcomputer

Operatingsystem

software

Applicationssoftware




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Provided by online services

Personal computing today


User’s responsibility Purchasing,using

Personalcomputer

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Provided by online services

DataData

DataData

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Personal computing tomorrow


Bloatware or the network computer

• Would the browser really become the OS?• Would communications functions really take over?• Would an NC really be easy to use?• Aren’t high-speed connections required?• Doesn’t the NC run counter to computing trends?• Would users go for it?

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Yuh-Jzer JoungSystems Software The Power Behind the power