1.5 Systems Software Flashcards
(18 cards)
What are the two types of systems software?
1) Operating system - provides a platform on which users can run programs
2) Utility software - used to maintain the computer system
What is an Operating System?
An Operating System (OS) is a complex piece of software found on most computer systems
What are the main functions of an operating system?
1) Communicate with internal and external hardware via the device drivers
2) Provide a platform for different applications to run
3) Allow the computer to multi-task by controlling memory resources and the CPU
4) Deal with file management and disk management
Types of user interfaces
1) GUI (graphical user interface)
2) Command line interface
3) Menu interface
4) Natural language
User interfaces: What are features of a GUI? [3]
1) Windows, icons, menus, pointers (WIMP)
2) Visual, interactive and intuitive
3) Optimised for mouse and touch gesture input
User interfaces: What are features of a Command Line Interface? [6]
1) Text based
2) Less resource heavy compared to a GUI
3) More commands than a GUI
4) Efficient
5) For advanced users
6) Useful for automating processes with scripts
User interfaces: What are features of a Menu Interface? [3]
1) Successive (consecutive/sequential) menus presented to the user
2) Single options chosen at each stage
3) Often with buttons as a keypad
User interfaces: What are features of a Natural Language Interface? [3]
1) Responds to questions in spoken language
2) Not always reliable
3) Getting better all the time
Operating systems: multitasking
1) Running multiple applications at the same time by giving each application a small time slice of processor
2) this allows more than one program to be held in memory at a time, and data shared between them such as copy and paste
3) It also enables you to listen to music on your PC at the same time as word processing
Operating systems: memory management
1) When programs are loaded, the operating system decides where they are held in memory
2) Over time, the memory becomes fragmented as programs are loaded and closed because they use different amounts of memory
3) The operating system must keep track of different program fragments
4) When the memory is full, the operating system uses virtual memory
Operating systems: device drivers
1) Translates operating system instructions into commands that the hardware will understand
2) Each peripheral needs a device driver
3) Many are already built into the operating system
(data is transferred between devices and the processor, this process must be managed)
Operating systems: user management
1) Providing for different users to log into a computer
2) The operating system will retain settings for each user (e.g. icons, desktop backgrounds etc.)
3) Each user may have different access rights to files and programs
4) A client-server network may impose a fixed or roaming profile for a user and manage login requests to the network
Operating systems: file management
1) Data is stored in files
2) An extension to the filename tells the operating system which application to load the file into
3) The operating system may present a logical structure of files into folders and allow the user to rename, delete, copy, and move files
What is a utility system software?
1) A program which performs important maintenance tasks to improve the performance of a computer system
2) Computers often come with utility software and how this performs housekeeping tasks
3) Utility software is needed to perform additional tasks that may not be carried out by an operating system
Utility software: encryption
1) Encryption utilities use an algorithm to scramble plain text into cipher text
2) The text can only be decrypted and made readable again with a key
Utility software: defragmentation
1) Defragmentation utilities reorganise files on a hard disk, putting fragments of files back together, and it collects together free space
2) This reduces the movement of a read/write head across the surface of the disk, which speeds up file access
Utility software: data compression
1) Compression utilities reduce the size of a file so that it takes up less space and is quicker to download over the Internet
2) Compressed files must be extracted before they can be read
3) Depending on the algorithm used, data is either lost (reducing the quality of an image/sound e.g. JPEG) or represented in a different way using binary, retaining the original data in a new, compressed format (e.g. Zip)
Why shouldn’t solid state drives be defragmented? [3]
1) Solid state drives should not be defragmented
2) It is unnecessary as they have no moving parts
3) It also reduces their lifespan
