Operating System

Question 1

Operating Systems

Answer 1

Manage computer hardware, users and the resources used by software

Question 2

User interfaces

Answer 2

Provides a method for users to interact with a computer. E.g GUI (Graphical User Interface)

Question 3

What is a GUI?

Answer 3

A visual way of interacting with a computer using items such as windows, icons, menus and pointers, used by most modern operating systems.

Question 4

Menu- driven interface

Answer 4

Used by devices that have dedicated functions, e.g MP3 Player

Question 5

Command Line Interface

Answer 5

Requires little processing and can save on the need for an expensive graphics card

Question 6

Memory Management

Answer 6

To run a program, the computer must copy the program from storage into main memory

Question 7

How does Memory Management work?

Answer 7

• Data used by the program is copied into main memory
• The Operating System keeps a record of where each program and its data are located
• The Operating System will make sure not to overwrite existing programs and data

Question 8

Multi- Tasking

Answer 8

Where an operating system manages many tasks happening at the same time

Question 9

Example of Multi- tasking

Answer 9

Having a web browser open whilst playing music and messaging friends
Many other background processes are also running
Operating system decides which process will next run on the CPU and for how long

Question 10

Peripheral management and drivers

Answer 10

Operating system must manage getting inputs from and sending outputs to peripheral devices.

Question 11

Name 3 peripherals

Answer 11

Mice, keyboard, printers

Question 12

Device drivers

Answer 12

Program that controls peripheral devices such as printers, mice

Question 13

How does device drivers work?

Answer 13

• Each device communicates with the operating system via it’s own driver
• Many device drivers come with an operating system. but if you buy a brand new type of device, it will be supplied with a driver, which will need to be installed

Question 14

User management

Answer 14

Operating system is responsible for user logins and passwords which are stored in a file or database

Question 15

Disk and file management

Answer 15

Hard disk in a computer is a storage peripheral

Question 16

What does the operating system do?

Answer 16

• Manages where in the disk files are written
• Keeps track of where they are so they can be retrieved
• Makes sure no file overwrites another file

Question 17

What is the file management carried out by and what are the feature available?

Answer 17

Carried out by Operating System.
Features available:
- Naming files
- Allocating files to folders
- Moving files
- Saving files
- Copying files
- Deleting files

Question 18

Interrupts

Answer 18

Signals sent to CPU by external devices to indicate a event that needs immediate attention. They tell the CPU to suspend its current activities and execute appropriate instructions

Question 19

Hardware interrupts

Answer 19

Generated by hardware devices- e.g printer out of paper

Question 20

Software interrupts

Answer 20

Generated by programs- e.g divide-by-zero error will cause an error message to be displayed

Question 21

What is Utility software?

Answer 21

Operating system controls and manages the computer system. Utility programs perform extra functionality and housekeeping tasks that keeps the computer running efficiently

Question 22

Encryption software

Answer 22

Used to encode text so that it cannot be understood without knowing the key to decode it

Question 23

Encryption software utilities are commonly used to what?

Answer 23

• Encrypt entire hard disks so that the data cannot be understood if the computer is stolen
• Encrypt files and folders on a portable disk- e.g USB removable storage
• Encrypt communication with websites
• Encrypt data in an organisation’s database- sensitive data- e.g passwords

Question 24

Disk Defragmentation

Answer 24

When you save a large file it may not fit on the disk in consecutive memory locations. In order to read the file, the drive head will need to move to more locations. This makes it slower to access files and programs. Defragmenting the hard disk reorganises files so they are stored together. Read times are far faster and free space is in 1 place so new files do not need to be fragmented.

Question 25

Data Compression Software

Answer 25

Utilities such as WinZip enable users to compress and decompress files or folders. This reduces the amount of storage space needed on a disk.