Lecture-6/ T. Nouf Almujally
description
Transcript of Lecture-6/ T. Nouf Almujally
COMPUTER SOFTWARE
Section 2 “System Software: Computer System Management ”
CHAPTER 4
Lecture-6/ T. Nouf Almujally
1
2 System Software
3
System Software
SystemManagement
Programs
System Development
Programs
Manages hardware, software, network, and data resources of computer systems
Operating systems, network management programs, database management systems,
system utilities
Helps users develop IS programs and procedures, and then prepare them
for processing
Includes Programming language translators and editors, CASE, and programming tools
Consists of programs that manage and support a computer system and its information processing activities.
4
Interface Between End Users & Computer
5 System Management Programs
6
Operating Systems
Integrated system of programs that…
Provides support services as the
computer executes
application programs
Manages the operations of the
CPU
Controls the input/out, storage
resources, and activities of the
computer system
The operating system must be loaded and activatedbefore other tasks can be accomplished
Examples of Popular Operating Systems :Microsoft Windows, Unix, Linux and MAC OS X
7
Operating System Basic Functions
• Command-driven
• Menu-driven• Graphical User
Interfaces (GUI)
Multitasking: is a task management approach
8
OS User interface Defined as the part of the information system
through which the end user interacts with the system
Command-driven interface: • The computer users have to input the command every time• (e.g., MS-DOCS).
Menu-driven interface: • The computers users use the menu to• execute the command instead of typing it in.
Graphical User Interface (GUI): • Defined as the part of an operating system users interact with that
uses• graphic icons and the computer mouse to issue commands and make• selections. The user uses a mouse to control the computer.
9
Resource Management• An operating system uses a variety of resource
management programs to manage the hw and network resources of a computer system.
• Including CPU, memory, secondary storage devices, input/output peripherals .
• Common functions:• Keeping track of where data and programs are
stored• Subdividing memory; providing virtual memory
capability • E.g. Memory Management Program
10
File Management• Control the creation , deletion, and access to files
of data and programs.• Keep track of physical location of files on
magnetic disks and other secondary storage devices.
11
Task management• Help accomplish the computing tasks of end
users.• The program control:
• Which task gets access to CPU• For how much time• Allocate a specific slice of CPU time to a particular
task.
• Multitasking: is a task management approach, allow for several computing tasks to be performed in a simultaneous fashion .
12
Other System Management Programs
• Database management systems chapter 5• Network management Programs chapter 6
This figure compares several types of system software offered by IBM and its competitors
13
Other System Management Programs
• Other system management software are marked as separate programs or included as part of an operating system:
• Utility programs (or utilities):• Programs like Norton utilities perform various housekeeping
functions, includes data backup, virus protection, data compression, etc.
• Performance Monitors:• Programs that monitor and adjust computer system to keep them
running efficiently.
• Security Monitors:• Monitor and control use of computer systems and provide warning
messages and record unauthorized use of resources.
14 System Development Programs
15
Programming Languages• Allows a programmer to develop the sets of instructions
that constitute a computer program.
16
Machine Languages
First Generation Languages
The most basic of programming languages
All program instructions had to be written using binary codes
Requires specific knowledge of theinternal operations of the CPU being used
Must specify the storage location for everyinstruction and item of data used
Difficult to work with, and error prone
17
Assembler Languages
Second Generation Languages
Developed to reduce difficultiesin writing machine language programs
Uses “assemblers” to convert the programsinto machine instructions
Symbols used to represent operation codesand storage locations
18
High-Level Languages
Third Generation Languages
Uses brief “statements” or arithmetic expressions
Statements translated into machine languageby compilers or interpreters
Less efficient than assembler language andrequires greater translation time
Machine-independent
Examples: BASIC, COBOL, FORTRAN
19
Fourth-Generation Languages
Fourth-Generation Languages
Variety of programming languages that arenonprocedural and conversational
Programmers specify the result wanted;the computer determines the sequence of
instructions that accomplish the result
Simplifies the programming process
Natural language; very close to English or human languages
Sometimes called fifth-generation (5GLs)
20
Object-Oriented Languages• Combines data elements and the procedures that will be
performed upon them into objects.E.g., data about a bank account and the procedures performed on it, such as interest calculations
21
Object-Oriented Languages
Easier to use and more efficient for graphics-oriented user interfaces
Most widely used software development languages
Reusable: can use an object from one application in another application
Examples: Visual Basic, C++, Java
Most object-oriented languages provide a GUI that supports visual programming
22
Web Languages
HTML A page description language that creates hypertext documents for the Web
XML Describes Web page content by applying identifying tags or contextual labels
to the data
Java Object-oriented programming language that is simple, secure, and platform independent
Java applets can be executedon any computer
• HTML, XML and Java are three programming languages that are important tools for building multimedia web pages, web sites and web-based applications.
23
Programming Software
Language Translator Program : is a program that translate instructions written in programming languages into machine language that computer can execute.
Assembler
Translates assembler language
statement
Compiler
Translates high-level language
statements
Interpreter
A compiler that translates and executes each
statement ina program,
one at a time instead of first producing a complete
machine language programs,
24
Programming Tools• Language translators have always provided some
editing and diagnostic capabilities to identify programming errors or bugs.
• However, most software development programs now include powerful graphics-oriented programming editors and debuggers.
• These programming tools help programmers identify and minimize errors while they are programming.
• An essential part of widely used programming languages like Visual Basic, C++ and Java.
25
Questions ..
26
Read from Chapter 4 (Section 2)
Resources..