Transcript Transparencies (updated, 10/28/98)

Systems Software
The Power Behind the power
Yuh-Jzer Joung
Systems Software
User
Applications Software
word processing, spreadsheet, communications, database, etc.
External utility
program
Systems software
Operating System
Language
translators
Hardware (computer plus peripheral devices)
Yuh-Jzer Joung
Systems Software
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
Yuh-Jzer Joung
Systems Software
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 menudriven interface. E.g., Windows 3.1 on top of DOS.
Hardware
Yuh-Jzer Joung
Systems Software
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.
Yuh-Jzer Joung
Systems Software
User Interface
C:\>VER
• Command-driven: requires you to enter a
command by typing in codes or words.
MS-DOS Version 6.22
• Menu-driven: allows you to choose a
command from a menu.
C:\>_
• Graphical: the graphical user interface
(GUI) uses images to represent options.
Icons are small pictorial figures that
represent tasks, functions, or programs.
Close…
File Edit View Layout Tool
Open…
Save…
Ctrl+F12
Save As...
F10
(C:)
Yuh-Jzer Joung
Systems Software
Shft+F10
(D:)
(E:)
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 .
Yuh-Jzer Joung
Systems Software
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.
Yuh-Jzer Joung
Systems Software
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.
Yuh-Jzer Joung
Systems Software
Microcomputer Operating Systems &
Operating Environments
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DOS
Macintosh System 7.X
Windows 3.X for DOS
OS/2 Warp
Windows 95/98
Yuh-Jzer Joung
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Windows NT
Unix
NetWare
Coming attractions
Systems Software
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, MSDOS 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.
Yuh-Jzer Joung
Systems Software
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.
Yuh-Jzer Joung
Systems Software
Windows for DOS
Windows is an operating environment made by Microsoft that lays a
graphical user interface shell around the MS-DOS or PC-DOS
operating system .
Yuh-Jzer Joung
Systems Software
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 .
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Clean “start”
Better menus
Long file names
The “Recycle Bin”
32-bit instead of 16-bit
Plug and play (PnP)
Yuh-Jzer Joung
Systems Software
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.
Yuh-Jzer Joung
Systems Software
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, ...
Yuh-Jzer Joung
Systems Software
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.
Yuh-Jzer Joung
Systems Software
Operating
System
Types of
Microprocessors
Single
User
Intel 8088,8086,
Yes
80286,80386
80486,Pentium
Macintosh Motorola 8030,
Yes
System
8040,68030,
Software
68040,PowerPC
Windows3.1 Intel 80286,80386, Yes
80486,Pentium
OS/2
Intel 80286,80386, Yes
80486,Pentium,
PowerPC
Windows95 Intel 80386,80486, Yes
Pentium
WindowsNT Intel 80386,80486,
Pentium,PowerPC,
DEC Alpha RISC
Unix
Almost all processors
NetWare
Yuh-Jzer Joung Intel 80386,80486,Systems Software
Pentium
Multitask
Multiuser
MS-DOS
PC-DOS
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
External Utility Programs
External utility programs are special programs that provide specific
useful services not performed or performed less well by other
systems software programs. Examples include:
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Screen saver
Data recovery
Backup
Virus protection
File defragmentation
Data compression
Memory management
Yuh-Jzer Joung
Systems Software
• 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 .
Yuh-Jzer Joung
Systems Software
Personal computing today
Provided by
online services
User’s responsibility:
Purchasing, installing,
upgrading, using
Applications
software
Data
Data
Personal
computer
Operating
system
software
Applications
software
Data
Applications
software
Data
Applications
software
Yuh-Jzer Joung
Systems Software
Data
Personal computing tomorrow
User’s responsibility
Provided by online services
Purchasing,using
Applications
software
Personal
computer
Universal
browser
Applications
software
Applications
software
Data
Data
Data
Data
Applications
software
Yuh-Jzer Joung
Systems Software
Data
Bloatware or the network computer
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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?
Yuh-Jzer Joung
Systems Software