Transcript CHAP_03 - Computer Science Home

Chapter
3
System Software and
Software Development
Module 3A
System Software
Module 3B
Programming Languages
Chapter
3
System Software

Operating Systems (OS):
The Computer’s Traffic Cop

Exploring Popular Operating Systems:
A Guided Tour
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System Utilities:
Tools for Housekeeping
Operating Systems

kernal/supervising program
memory resident
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The OS is much like a
computerized version of a
traffic cop, standing at the
intersection of the
computer’s hardware,
application programs, and
the user.
Operating Systems
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Managing Programs
single-tasking
multitasking
foreground application
background application
multiprocessing
Operating Systems
The OS manages
programs, parcels out
memory, deals with input
and output devices, and
provides means of
interacting with the user
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3A
Operating Systems

Managing Memory
partition
virtual memory
swap file
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Handling Input and Output
device drivers
User Interface

Types of User Interface
command-line
menu driven
graphical user interface (GUIs)
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User Interface functions
gain access (log on)
start (launch)
manage disks and files
shut down safely
Exploring Popular OS
Unix
 Xerox PARC & the first GUI
 MS-DOS
 Mac OS
 Microsoft Windows 3.x
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Exploring Popular OS
Microsoft Windows 95 and 98
 Microsoft Windows CE
 Microsoft Windows NT
 Linux
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For the latest on Linux,
visit Linux online
System Utilities:
Tools for Housekeeping
Backup utilities
 Antivirus software
 File compression utilities
 File defragmentation programs
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Antivirus Software
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Norton AntiVirus is a
utility that works by
examining all the files
on a disk, looking for
the tell-tale
"signatures" of virus
code
Programming Languages

First Generation : 1s and 0s
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Second Generation: A little Easier
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Third Generation: Programming Comes of Age
Fourth Generation:

Getting away from Procedure
Module 
3B 
Object Oriented: A Revolution in the Making?
A Guide to Programming Languages:
One Size doesn’t Fit All
Programming Languages

First Generation
machine language: 1s and 0s
machine dependent
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Second Generation
assembly language
low-level
mnemonics
Third-Generation Languages
(3GL)
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Description
Procedural
high-level

source code/object code
low-level
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Compilers

Interpreters
Third-Generation Languages
(3GL)
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Spaghetti Code
software crisis

Structure Programming
Pascal/Algol
low-level
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Modular Programming
Fourth-Generation Languages
(4GL)
 report
generators
 query languages
Structured Query Language (SQL)
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natural language
Object-Oriented Programming:
A revolution in the making
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Eliminating the program vs data distinction
What is an object?
Classes
Inheritance
Rapid Application Development (RAD)
Middleware
A Guide to Programming
Languages

COBOL
business programming
Y2K

Fortran
scientific/mathematical/engineering
good for complex problems
Module
3B
Learn more about COBOL by reading the
FAQ located on the Oxford University
Library Automation Service
Structured & Modular
Languages
 Ada
 Visual
Basic
event-driven
Vbscript
ActiveX controls
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Pascal
Object Oriented Languages
Smalltalk
 C and C++

# include <iostream.h>
void main ()
{
cout <<“Hello
World!”;
A simple C++ program that prints Hello
World to the screen
Module
3B
If you’re thinking about a career in
computer science, C++ is the language to
learn. For more information see the C++
Virtual Library and C++ FAQ Lite
Object Oriented Languages
Java
 JavaScript

class Hello World {
public static void main (String args
{}) {
System.out.println (“Hello World!”)
}
Simple Java code
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To learn more about Java, visit Java’s
home page at Sun Microsystems