3.6 Operating systems Flashcards
1
Q
Software
A
Instructions that tell the computer what actions to carry out
2
Q
Application software
A
Software that carries out useful work for us
3
Q
System software
A
Software that enables the computer to work properly; the instructions help the CPU to run the whole computer system
4
Q
Purpose of an operating system
A
- Interacts with a computer’s hardware, transmitting your commands into language the hardware can interpret
- Provides an easy way for us to interact with computers and run applications
5
Q
8 functions of an operating system
A
- Provides a user interface to interact with the computer
- Runs applications, executes and cancels processes
- Multi-tasks (allows multiple applications to run at the same time)
- Manages memory (transfers programs into and out of memory)
- Manages peripherals (writes to peripheral devices, eg. storage attached to computer)
- Organises (creates a file system to organise files and directories)
- Security (provides security through user accounts and passwords)
- Utilities (provides tools for managing and organising hardware, eg. antivirus, backup software)
6
Q
Booting up
A
- When a computer is switched on, start-up instructions called BIOS (basic input/output system) are loaded (copied) into main memory/RAM from ROM. The BIOS instructions are executed - they start to control the computer’s peripherals, and look in secondary storage for the operating system.
- Then, the operating system is loaded into RAM from secondary storage. The OS is typically stored on the computer’s hard disk. Once the OS is in place the computer can start to work.
7
Q
Interrupt
A
A signal sent from a device or software to the processor/CPU, and causes the processor to temporarily stop what it is doing and service the interrupt
8
Q
What is the use of interrupts, besides dealing with hardware or software errors?
A
Interrupts allow computers to carry out many tasks, or to have several windows open at the same time
