1.2

• BIOS:

  • Basic Input / Output System
  • Software that is stored in non-volatile memory.
  • Starts the boot loader (bootstrap)
  • Stores hardware settings
• Device Driver:

  • Translates commands from the operating system into hardware specific commands that a device understands.
• Distributed OS:

  • A model where distributed applications can run on multiple computers linked by communications.
• Embedded OS:

  • Highly specialised and limited operating system for embedded systems
  • Designed for a specific type of machine / computer
• First Come First Serve:

  • a scheduling algorithm that deals with each user or task in the order that they arrive in.
  • Executing process cannot be stopped once started.
• Intermediate code:

  • Code produced by the compilation process
  • Code that is translated by a virtual machine.
• Interrupt:

  • A signal generated by another component to gain attention of the processor.
• ISR (Interrupt Service Routine):

  • A software routine that hardware invokes in response to an interrupt.
• Memory Management:

  • The process of organising the computers main memory.
• Multi-Level feedback queue:

  • A scheduling algorithm that deals with processes based on a set of priorities and rules using multiple queues.
• Multi-tasking operating system:

  • Any type of system that is capable of running or appearing to more than one program at a time.
• Multi-user operating system:

  • Any operating system designed to allow multiple users to log in and connect from different locations / machines at the same time.
• Operating System:

  • Manages the computers processors, memory, files, logins and user settings.
  • Provides a user interface.
• Paging:

  • Used in virtual memory
  • The organisation of memory into physics, fixed-sized units called pages.
• Real Time OS:

  • An operating system intended to serve real-time application data as it comes in without delays.
• Round Robin:

  • Each process has a given time slice
  • After which it returns to the back of the queue.
• Scheduling:

  • A method by which central processor time is allocated to processes.
• Segmentation:

  • Used for virtual memory
  • A program is split into logical sections of different sizes.
• Shortest Job First:

  • Queue is sorted in order of estimated processing time before process begin executing in order.
  • Processes cannot be suspended once started.
• Shortest Remaining Time:

  • Queue is sorted in order of estimated processing time before processes begin executing in order
  • Processes can be suspended and return to the queue if a shorter job arrives
  • Queue is then sorted again when new processes arrive.
• Virtual Machine:

  • An emulator of a particular computer system
• Virtual Memory:

  • Using part of the secondary storage as if it were RAM.
  • Allows more applications to be open than physical memory could hold.