What is an operating system
a group of programs that manages the computer’s resources
what functions does the operating system provide
- providing a user interface
- memory management
- peripheral management
- user management
- file management
what are the types of user interface
- Graphical user interface [WIMP (windows, icons, menus, pointers)]
- Command-line interface
- Menu interface
- natural language interface
what does a user interface do
provide the way in which you interact with the computer as a human being
describe a graphical user interface
- visual, interactive
- windows, icons, menus, pointers
describe a command-line user interface
- text based
- more commands to learn so for advanced users
- efficient and less resource heavy
describe a natural language user interface
- responds to questions in a spoken language
- not always reliable but getting better all the time
describe a menu user interface
- successive menus presented to the user
- single options chosen at each stage
- often interacted with through buttons on a keypad
(eg. cash removal point)
describe how the operating system performs memory management
- over time the memory becomes fragmented as programs are loaded and closed because they use different amounts of memory
- when new programs are loaded into memory, the packets are separate and have to be put wherever there is space
- the operating system shuffles the packets together to collect free space for the incoming programs
why is fragmentation bad
all the packets are spread out so it is inefficient for the moving read/write head to have to collect each one individually. this appears to the user as the computer running slowly
on what storage device is a defragmentation system needed
- magnetic hard disks
on what storage device is a defragmentation system not needed
solid state drive as it has no moving parts. defragmentation would actually decrease its life span
what is multi tasking
when a computer switches rapidly between several tasks
how is multi tasking performed on a computer
The processor allocates a small amount of time to each process and cycles between them. this is so it appears to the user as if they are all working simultaneously
what is a peripheral of a computer
any computer hardware components that are not the CPU. Peripherals include input, output and storage devices.
how does the operating system manage peripherals
it uses a device driver which translates the operating system instructions to print the document into a series of instructions which a specific piece of hardware will understand. this means you can print the same document and it will look the same no matter what type of printing technology is used.
what is buffering
used to compensate for the difference in speeds between the rate that data is received for printing or streaming and the rate at which it can be printed or streamed
what is a data buffer
- an area of RAM controlled by the peripheral management system.
- when you give the command to print a document (for example) the data is copied to the print buffer, the print management system retrieves the data from the buffer and sends it to the printer
- if the buffer is not big enough to hold all the data, the buffer will be refilled during printing as space becomes available
what does the user management system do
enables a network administrator to allocate accounts and set different access rights for different users
- the system can also
=identify all users on a network
=manually log out users
=monitor when and how long each user is logged in
functions of the user management system
control
- allocation of an account
- access rights
- security
why does a computer need a file management system
to support the creation, copying, moving, deletion and renaming of files and folders
what things does a file management system do
- allows the user to rename, move, delete and copy files
- help set permissions and access rights
- allow user to sort files into folders and directories
purpose and functionality of utility software
…
What types of utility system software are there
- encryption software
- defragmentation
- data compression
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1.1 Systems Architecture31
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1.2 Memory and storage44
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1.3 Computer networks, connections and protocols90
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1.4 Network Security34
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1.5 Systems software30
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1.6 Ethical, Legal and Cultural, and environmental Impacts of digital technology24
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2.1 Algorithms16
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2.2 Programming Fundamentals29
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3rd Year10
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Retest17
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not on flashcards1
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2.3 Key terms18
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2.3 Producing robust programs27
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2.4 Boolean Logic1
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2.5 Programming languages and integrated development environments20
