1.5.1 Operating systems

What is an operating system?

• An operating system (OS) is software that helps to manage the resources of a computer system and provide the interface between the user and the computer’s hardware.

What is the function of a user interface?

• to provide a method for human users to interact with a computer system

What are the features of a graphical user interface (GUI)?

desktop

• multiple windows can be opened and switched between

• icons are shortcuts to applications and files

• menus can be opened to display files and shortcuts

• a pointer is used to select

• the interface can be customised

• folder and file system is displayed- allowing for copying, searching, sorting and deleting data.

smartphone

• no pointer

• windows (apps) generally take up the full screen

What are the advantages and disadvantages of a GUI?

advantages

• interactive

• intuitive - easy to use

disadvantages

• resource heavy

What are the features of a command line interface?

• text-based and requires users to interact with the system by typing commands

What are the advantages and disadvantages of a CLI?

advantages

• for expert users, this can be more efficient

• more commands

• less resource heavy

• requires little processing or an expensive graphics card

disadvantages

• complicated process and mistakes could easily accidentally delete data

• many commands to learn

What are the features of a menu driven interface?

• displays data in a series of successive menus

• one option chosen at each

• used for devices with a dedicated function. Examples include cash machines (ATMs) and old iPods.

What are the advantages and disadvantages of a menu driven interface?

advantages

• generally user friendly and easy to use as commands do not need to be memorised

disadvantages

• can be hard to find specific data through a large number of menus without a search feature.

What are the features of a voice driven interface?

• controlled by speaking commands aloud to a listening device in spoken language

• Examples include Amazon's Alexa devices, Apple's Siri technology and Google Home.

What are the advantages and disadvantages of a voice driven interface?

advantages

• intuitive, can be used hands-free and helps to speed up processes

disadvantages

• commands may be misheard or limited in what can be performed - unreliable

How does data management and multitasking work?

• the program in use and the data it is using must be copied from storage to RAM temporarily to be processed

• the OS manages the transfer of data and programs to and from the hard drive and RAM

• the OS can only perform one process at a time but the data is managed so that it appears processes are running simultaneously

• only possible if the OS can support multitasking and if there is enough memory to hold more than one program in primary memory at a time

What is peripheral management?

• a peripheral is an external device connected to a computer system to input or output data.

• device driver is a program that provides an interface for the OS to interact and communicate with an external device - hardware dependent and OS-specific - the driver translates the OS’ instructions into a format the specific hardware can understand.

• each device communicates with the OS via its own driver

• drivers can be updated

• allow any device to be used with the OS

• CPU and the peripheral will process data at different speeds so a buffer is typically used to temporarily store data until it can be processed.

How are users managed?

• OS allows users to create, manage and delete individual accounts

• User accounts can be granted different access rights such as an administrator or guest.

• manages security settings such as allowing passwords to be reset and can also be used to monitor login activity.

What is the process of sending files to a printer?

• data can be sent much faster than it can be printed

• data is sent to a print queue or buffer

• then it is transmitted to the printer

• printer sends back its status to the OS which reports any errors to the user

How are files managed?

• the hard disk is a storage peripheral

• the OS manages where on the disk files are written , keeps track of their location and makes sure no file overwrites another file

• creates and maintains a logical management system to organise files and directories (folders).

• allows files to be named, renamed, opened, copied, moved, saved, searched for, sorted and deleted.

• It also allows users to set access rights for specific files and view file properties.