Transcript Judul - my documentation

Software: System
Software
Sumber:
Chapter 3. Software: Tools for
Productivity and Creativity, p.117
Williams, B.K, Stacy C. Sawyer (2007).
Using Information Technology: A
Practical Introduction to Computers &
Communications. Seventh Edition,
McGraw-Hill, New York. ISBN-13: 978-007-110768-6
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• menjelaskan: pengertian dan komponen
system software, dan fungsi-fungsi sistem
operasi
2
Outline Materi
• System Software: The Power behind the
Power
• The Operating System: What It Does
• Other System Software: Device Drivers &
Utilities
• Common Features of the User Interface
• Common Operating Systems
3
System Software: The Power behind
the Power
• Application Software
– Software developed to solve a particular problem for
users
• Either performs useful work on a specific task
• Or provides entertainment
– We interact mainly with this software
• System Software
– Enables application software to interact with the
computer
– Helps the computer to manage its own internal and
external resources
3-4
System Software: The Power behind the
Power
• System Software has 3 basic components
– Operating System (OS)
• The principal component of system software
• Low-level, master system of programs to manage basic
computer operations
• Some hardware requires specific Operating Systems
– Macintosh computers run Macintosh OS
– PCs run Microsoft Windows, Linux, or BSD
– Device Drivers
• Help the computer control peripheral devices
– Utility Programs
• Used to support, enhance, or expand existing programs in
the computer
3-5
The Operating System: What It Does
•
Booting
– The process of loading an OS into the computer’s
main memory
– The steps are:
1. Turn the computer on
2. Diagnostic routines test main memory, CPU, and other
hardware
3. Basic Input/Output System (BIOS) programs are
copied to main memory
–
–
BIOS contains instructions for operating the hardware
The computer needs those instructions to operate the hardware
and find a copy of the OS
4. Boot program obtains the OS and loads it into
computer’s main memory
3-6
The Operating System: What It Does
The Operating System: What It Does
• Central Processing Unit (CPU) Management
– Kernel is the supervising software that manages CPU
• Kernel must remain in memory while the computer runs
• If another program uses the kernel’s memory when the
kernel needs it, the computer will crash
– Memory Management
• OS keeps track of memory locations to prevent programs
and data from overlapping each other
• Swaps portions of programs and data into the same memory
but at different times
• Keeps track of virtual memory
– Queues, Buffers, Spooling
3-8
The Operating System: What It Does
• Central Processing Unit (CPU) Management (continued)
– Queues, Buffers, Spooling
• Queue: First-in, First-out (FIFO) sequence of data or
programs that waits in line for its turn to be processed
• Buffer: The place where the data or programs sit while they
are waiting
• To Spool: The act of placing a print job into a buffer
– Needed because the CPU is faster than printers
– The CPU can work on other tasks while the print jobs
wait
3-9
The Operating System: What It Does
• File Management
– A file is either a
• Data File: a named collection
of data
• Program File: a program that
exists in a computer’s
secondary storage
– The File System arranges
files in a hierarchical manner
• Top level is Directories (aka
Folders)
• Subdirectories come below
Folders
– Find files using their
pathname
• C:/MyDocuments/Termpaper/section
1.doc
3-10
The Operating System: What It Does
• Task Management
– Required for computers that accommodate multiple users
– Required for computers that allow multiple simultaneous
applications
– Methods of processing two or more programs
Multitasking
Time-sharing
By one user on one processor
By multiple users in round-robin
fashion on one processor
Multiprogramming
Multiprocessing
By multiple users concurrently on
one processor
By one or more users
simultaneously on two or more
processors
3-11
The Operating System: What It
Does
The Operating System: What It Does
• Security Management
– Operating Systems permit users to control
access to their computers
– Users gain access using an ID and password
– You set the password the first time you boot
up a new computer
– System Administrators can set up new
accounts and assign new passwords
3-13
Other System Software: Device
Drivers & Utilities
• Device Drivers
– Specialized software programs that allow input and
output devices to communicate with the rest of the OS
– When you get a brand-new printer or monitor, you may
also need to install the device driver for it
– Device drivers come with new hardware, or download
from the manufacturer’s website, or sites like
www.driverguide.com or www.windrivers.com
3-14
Other System Software: Device
Drivers & Utilities
• Utilities
– Service programs that perform tasks related to the
control and allocation of computer resources
– Some come with the OS, others can be bought
separately like
• Norton SystemWorks, McAfee Utilities
Other System Software: Device
Drivers & Utilities
• Practical Utility programs perform the following
tasks
–
–
–
–
–
–
Virus protection
Data compression
File defragmentation
Disk scanner & disk cleanup
Backup
Data recovery
3-16
Discussion Question: How many
of you have lost important files
such as a term paper? Didn’t
you wish you had made a
backup copy? ALL data media
are subject to possible failure
and data loss!
Common Features of the User
Interface
• User Interface
– The user-controllable display screen you use to
interact with the computer
• Keyboard and Mouse
– User input devices that you use to interact with the
display screen
– Both devices have special-purpose keys
• Keyboard Special-purpose keys: Esc, Ctrl, Alt, Del, Ins,
Home, End, PgUp, PgDn, Num Lock
• Mouse special-purpose keys: left-click, right-click, and (on
some mice) scroll wheel or center click
3-17
Common Features of the User
Interface
• Keyboard
– Function Keys – let you quickly perform specific tasks
– Escape Key – lets you quit a task
– Ctrl and Alt – use combination with another key to bypass using the
mouse – Ctrl + S will save a document, Alt + Tab will let you switch
between running applications
3-18
Common Features of the User
Interface
• Keyboard continued
– Application key – quickly displays the shortcut
menu for any item on your screen
– Status lights – indicate if your Num Lock or
Caps Lock keys are on
– Numeric Keypad – allows you to type in
numbers when the Num Lock light is on
3-19
Common Features of the User
Interface
• Mouse
– Handy tool
for dragging
and
dropping
text,
graphics
– Useful for
navigating
menus on
unfamiliar
applications
3-20
Common Features of the User
Interface
• Graphical User Interface (GUI)
– Allows you to use a mouse or keystrokes to select
icons and commands from menus
– Replaces command-driven interfaces used in earlier
programs
– Three main features are: desktop, icons, and menus
• Desktop: The system’s main interface screen
• Icon: Small pictorial figure that represents a program, data
file, or procedure
– Rollover: A small text box that explains the icon when
you roll your mouse over it
• Menus: A list of built-in commands and/or options from which
to choose
3-21
Common Features of the User
Interface
• To start an application, pick one of 3
methods:
– Click on the Start button on the lower left corner of the Windows
desktop
– Click on the My Computer icon on the desktop, find the
application executable on your hard disk, and click it
– Click on the My Documents icon on the desktop, find the
document you want to open, and click it. It should automatically
open the application that created it, if you have that application
installed
3-22
Common Features of the User
Interface
• Most Operating Systems have the following:
– Title Bar: runs across the top of the display window
– Menu Bar: shows the names of the pull-down menus available
– Toolbar: Displays menus and icons representing the mostfrequently used commands
– Taskbar: The bar across the bottom of the Windows screen that
contains the Start button
– A window: A rectangular frame on the computer screen through
which you can view a file of data or an application
3-23
Common Operating Systems
• Platform
– The particular processor model and operating system on which a
computer system is based
• Operating Systems are platform-specific
• PC (Wintel) platforms
– Dell, Compaq, Hewlett-Packard, IBM PCs
– Originally ran Disk Operating System (DOS)
– Currently run Linux, Unix, Windows
• Apple (Macintosh) platforms
– Run Mac OS (System 9 was proprietary, OS X is Unix-based)
3-24
Common Operating Systems
• Mac OS
– The OS that runs on Apple Macintosh computers
– Pioneered the easy-to-use GUI
– Proprietary OS
• System 9 is OS from 1999, but still popular
• Mac OS X is based on BSD Unix kernel
• Tiger is 2005 release of Mac OS X; features include
– Spotlight – a desktop search engine for locating files on
local hard disk
– Dashboard – for creating desktop “widgets”
– Automator – automatically helps users to script repetitive
tasks
3-25
Common Operating Systems
• Unix, Solaris, BSD
– Developed at AT&T Bell Laboratories in 1969 as
minicomputer operating system
– Is a multitasking operating system with multiple users
that has built-in networking capability and a version
for every platform
– Unix interface
• GUI – An optional shell program that starts after the kernel
• Command interface – starts when kernel loads
3-26
Common Operating Systems
• Linux
– A flavor (version) of Unix
– A free, nonproprietary version of UNIX
• May legally be downloaded and used for free
• May legally be modified for free, as long as modifications
aren’t copyrighted
• In 2000, adopted by China as national standard OS
– Linux vendors produce Linux Distributions
• Software is distributed for free
• Support services are sold for a profit
– Many PCs are set up to dual-boot Linux and Windows
3-27
Common Operating Systems
• Operating Systems for Handhelds
– Palm OS
• Dominant handheld OS
• Proprietary OS requires proprietary software
– Windows CE
• Has familiar Windows look and feel
• Can be directly programmed using Visual Basic 2005
– Symbian OS
• Symbian is world’s largest producer of smartphone software
• Software is open-source
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Kesimpulan
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