1.5 Sythems Software Flashcards
Two type of system software
Operating system- provides a platform on which user can run programs
Utility software- used to maintain the computer system
Types of user interface 4
Graphical user interface GUI
Command line
Menu
Natural language
Natural language
Respond to question is spoken language
Not always reliable
Getting better all the time
Menu
Successive menu presents to the user
Single option chosen at each stage
Often with button on a keypad
Command line
Text based
Less resources heavy compared to a GUI
More command then a GUI
Efficient
For advanced users
Useful for automating processes with scripts
Graphical user interface
Windows, icons, menus, pointers (WIMP)
Visual
Interactive
Intuitive
Optimised for mouse and touch gesture input
Multitasking
Running multiple application at the same time by giving each application a small time-slice off processor time
This allows more than one program to be held in memory at a time, and data shared between them such as copy and paste
It also enable you to listen to music on your PC at the same time as word processing
Memory management
When programs are allowed, the operating system decide where they are held in memories
Overtime the memory become fragmented as programs are loaded and close because they use different amount of memory
Operating system must keep track of different program fragment
When the memory is full, the operating system use virtual memory
Device drivers
Translate operating system instruction into command that the hardware will understand
Each peripheral needs a device driver
Many are already built into the operating system
User management
Providing for different user to login into a computer
Operating system will retain settings for each user such as icon or laptop background
Each user have different access right to files and programs
A client server network may impose a fixed or roaming profile for a user, and manage login request to the network
File management
Data is stored in files
An extension to the filename tells the operating system which application to load the file into
The operating system may present a logical structure of file into folders, and allowed the user to rename, delete, copy and move files
The function of operating system 8
User
Application software
Memory management
User interface
Hardware
Utility program
Fire management
Device driver
Utility systems software 3 different ways
Encryption
Defragmentation
Data compression
Encryption
Encryption utilities use an algorithm to scramble painting into cipher text
The only decrypted and made readable again with a key
Defragmentation
Recognise files on a hard disk, putting fragments of files back together, and it collects together free space
This reduced the movement of a read/ write head across the surface of the discs, which speed up file accessing
Solid State drive not be defragmented
It is unnecessary as they have no moving parts
It’s also reduced their lifespan
Data compression
Compression utilities reduce the size of a file so that it takes up less space, and is quicker to download over the Internet
Compressed files must be extracted before they can be read
Depends on the algorithm used data is lost, reducing the quality of an image or sound
Data compression
Compression utilities reduce the size of a file so that it takes up less space, and is quicker to download over the Internet
Compressed files must be extracted before they can be read
Depends on the algorithm used data is lost, reducing the quality of an image or sound
