1.5 Systems software Flashcards
What is an operating system?
An OS is software that manages the resources of a computer system & provides the interface between the computer’s hardware and user
List the 5 main functions of the OS.
Memory Management (Fragmentation & Multitasking)
Peripheral Management (drivers)
User Management
File Management
User Interface
What is fragmentation?
The splitting of a new program when storing into RAM, and its fragments are saved in non-contiguous space
Why is fragmentation needed?
Fragmentation is needed when there is limited contiguous space to store a file
What are the disadvantages of fragmentation?
Increases access time since they take longer to load due to the increased distance between the fragments
What is the role of the OS in memory management?
It transfers programs in & out of memory from the hard drive when processing is required.
It removes programs from RAM when they are closed to free up space.
Executes fragmentation
What is multitasking and why do we need it?
Multitasking is needed when there are 1+ programs open at the same time.
The processor can only run one program at once, so it allocates a small amount of time for each program & switches between them so quickly it appears to be simultaneous.
Explain the role of the OS in peripheral management.
The OS manages the data transfer between peripherals & processors. The drivers are programs that provide an interface for the OS to communicate with a peripheral
Explain the role of the OS in user management.
The OS allows users to create, manage & delete accounts, which can be granted access rights.
The OS will also manage security settings such as allowing passwords to be reset & monitoring login activity
Explain the role of the OS in file management
The OS:
creates & maintains a logical management system to organise files
allows files to be named, searched for, deleted etc.
lets users to set file access rights & view file properties.
Explain the OS’s role in user interface
The OS provides a user interface, which is needed for a human to interact with the computer system.
Types of user interface
GUI
Command line
Touch-sensitive
Menu-driven
Voice-driven
What is utility software?
Dedicated programs to maintain & organise a computer system
They are required to run additional tasks not performed by the OS
Examples of utility software:
anti-malware
firewalls
encryption
compression
defragmentation
What is defragmentation?
When empty spaces are collected together on the hard disk drive & file fragments are moved to be stored together.
What are the effects of defragmentation?
Fewer disc accesses needed (file fragments can be read consecutively)
Less time to read & access a defragmented file (data is stored contiguously)
Quicker to save new files (more free contiguous space, so no fragmentation needed)
