1.2.1

• device managers works closely with special...

  system software
• examples of device management...

  keyboard, mouse etc
• what are device drivers

  these are small pieces of software that installs onto your computer
• what is the purpose of a device management

  keeps track of which devices are connected to which ports
• what other purposes does device management have

  allows applications to read/write data to each device
• hardware interrupt

  how can they occur

  this can occur when an input or output operation completes
• interrupt is an efficient way to tell the computer when a...

  job needs to be completed
• interrupt service routine (ISR)

  what is it

  is a set of instruction that need to be done as part of an interrupt process write
• is polling an efficient way of interrupts

  no its inefficient
• software interrupts

  where does this come from

  this comes from a piece of software that need to terminate or request services from the OS to complete a task
• what is an example of software interrupt

  opening a document
• what is an interrupt

  this is a signal from a piece of soft/hardware that tells the CPU that it needs some attention
• what is polling

  this is when CPU polls every piece of software and hardware if it needs anything to be done
• what is the process manager purpose

  modern operating systems allow users to run multiple programs at once
• what is the purpose of managing memory

  controls the allocation of the RAM to each running process
• what are 3 examples of Mangers

  device manager

  memory manager

  process manager
• what does API stand for

  application programming interface
• what does device manager do

  allocates resources to external hardware devices and allows them to be used by applicators
• what does process manager do

  controls the allocation of CPU
• what is an API

  set of code libraries that software developers can use to write applications for that OS
• what is Manger

  controls pieces of hardware that OS are responsible of
• what is operating systems(OS)

  this is essentiaal piece of software that is loaded when a computer boots up
• what is the purpose of operating system

  to control the hardware within a computer
• in segmnetation ther is no...

  physical split
• programs can be split across lots of pages that are non-contiguous

  what does non-contiguous mean

  managed by?

  not all together

  manager by a table map
• segmentation can use ___ to store unuser part of program in the ____ to free ___ for something else

  what are the words

  virtual memory

  virtual memory

  space
• what is multitasking

  modern OS allow multiple applications to run at once
• what is Paging

  this splits the main memory (RAM) into 4kb sections known as pages
• what is segementation

  each program is given a logical division of memory to operate in
• first come first served

  how are jobs completed

  jobs are completed in the order they came on regardless of the time taken to complete
• first come first served

  what are 2 disadvantages

  can cause delays when getting job done

  FCFS generate bad performance with a computer system
• first come first served

  what is one advantage

  it is easy to manage and set up
• is round robin east to manage and set up

  yes
• multi-level feedback queues

  if a job is waiting too long it will...

  be moved to higher priority location in another queue to get the job completed quicker
• multilevel feedback queues

  is the most complex form of schedulling but...

  give the best results
• multilevel feedback queues

  may offer best results but is...

  very CPU intentive
• round robin

  if a job is completed, the next job is loaded, so if a job is not completed

  what happens

  it is pushed to the bottom of the queue and waits for the next slot of CPU time
• shortest job first

  not very feasible for implementation as...

  OS rarely know how long each job is
• shortest job first

  what is it

  is a scheduller that selects the shortest job in the queue to complete first
• shortest remaining time

  uses very little CPU usage,

  why

  as it is only compares a job when its done or arrived