System Software

Computer and Information Technology – Core Module – System Software

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Computer & Information Technology System Software Classification of Software Software

Application Software

Device Driver

1.

2.

System Software

Utility Software

Operating System

Application Software User can have high degree of control to the operations of the software  E.g. Word processing: MS Word  Image editing: Adobe Photoshop System Software Software operates automatically, sometimes with accordance to user’s  configuration Three types  Device driver  Utility Software  Operating System 

Device Driver 1. For computer to get access to peripheral devices 2. Plug-and-play Use of hardware after connecting to computer without explicit installation  of device driver Basic driver programs for common hardware are pre-installed in the  Operating System Utility Software 1. Utility software can be a software package or included in the operating system 2. Functions and examples Improve computer performance  Disk Defragmenter: Reduce fragments on the disk  Disk scanning and cleaning: Scan the disk to detect any abnormality  and remove unnecessary files

Computer and Information Technology – Core Module – System Software

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File management Program uninstaller: Remove application software and related files and  setting File compressor / decompressor: Compress / Decompress files  File backup and recovery: Make a copy of files for later recovery when  necessary Computer protection Antivirus software: Prevent and detect computer viral infections and take  appropriate actions when necessary Firewall: Control the incoming and outgoing data traffics  

3.

Operating System 1. An essential program for every computer to coordinate interactions between users, application software and hardware 2. Manage, optimize and monitor the usages of computer resources, such as hardware, memory, file and network connection 3. Function Device configuration  Control and manage peripheral devices connected to the computer  Allow application software and user to get access to the devices  File management  Transfer file between main memory and secondary storage  Manage file folders  Allocate the secondary storage space  Provides file protection and recovery  Memory management  Allocate the use of RAM to requesting processes  Monitor the running processes and take appropriate action if necessary  Interface  Allow the computer to run application software  Provide an user interface for users to operate the computer system  Network communication management  Set up and coordinate the network communication activities  Other functions provided in certain Operating Systems  Maintain security by restricting users’ access privilege  Network protection, e.g. Firewall  Event logging 

Computer and Information Technology – Core Module – System Software

4.

Different classification Single-user vs Multi-user 

Single-user Multi-user



No. of concurrent users 1 >1

Example Win XP, PalmOS Linux, Unix, Windows NT

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Application Handheld PC, home computer Network servers

Single-tasking, Multi-tasking and Multi-processing No. of concurrent

Example

Remark

Single-tasking

processes 1

DOS

Multi-tasking Multi-processing

>1 >1

Win XP, Linux, Mac OS Red Hat Enterprise Linux



More than one processors

Win Server 2003



Usually designed for servers



Standalone OS, Network OS (NOS), Embedded OS

Standalone OS



Run on desktop computer, notebook computer, etc.

Network OS

 

Able to operate with or without network Designated for any scales of network

Embedded OS



OS is programmed on the ROM



Usually found in digital devices, e.g. PSP, Mobile phone



Command-line Interface vs Graphical User Interface (GUI) Features

Command-line



Users have to memorize the commands

GUI

 

More time-saving, more suitable for professional users The uses of mouse, icon, windows and menu



More time-consuming, suitable for all levels of user

Example DOS, UNIX

Win XP, MAC OS

Platform 1. Platform = Type of CPU + OS e.g. Pentium 4 processor + Win XP 2. Software normally can run on a particular platform The necessary platform is clearly written as part of the specification  Problem:  Availability: Software may not be available on some platform  Compatibility: Software running on a platform may not be able to run  on other platforms 3. Cross-platform technologies

Computer and Information Technology – Core Module – System Software

 

Same program can be run on different platforms Example: Java Virtual Machine (JVM), .NET framework

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