What is an operating system? - ANSWER A program that acts as an
intermediary between a user of a computer and the computer hardware
What are the 3 main functions of an operating system? - ANSWER (1) manage
the computer's resources, such as the central processing unit, memory, disk
drives, and printers
(2) establish a user interface to make the system more convenient and solves
user problems
3) execute and provide services for applications software.
What two things does the OS do - ANSWER (1):Allocates resources and
schedules requests for fair and efficient use.
(2): Controls the execution of programs to prevent errors and improper use of
the computer
What does the kernel do? - ANSWER It is located in the heart of the operating
systems. It deals with low-level hardware operations. Runs at all times.
What is a bootstrap program? - ANSWER Loaded at power-up, initializes all
aspects of system, loads operating system kernel and starts execution.
How is a computer organized? - ANSWER -There are one or more CPUs
(cores or chips) and device controllers that connect via a shared bus to access
shared memory.
What does a CPU do with device controllers? - ANSWER Moves data to /
from buffers in controllers to / from main memory
What does a device controller do when completing an operation - ANSWER It
informs the CPU via an interrupt.
What is an interrupt? - ANSWER Signal from hardware or software indicating
that an event has occurred or that a process needs attention.
, What are interrupts caused by an error or user request, what generates them? -
ANSWER Trap or exception, software.
How are interrupts handled? - ANSWER (1)The execution is immediately
transfered to the handler
(2) OS preserves the CPU state by storing registers and program counter.
(3) handler takes action depending on the interrupt type.
What are the 3 advantages of multiprocessor systems? - ANSWER (1):
Increases throughput
(2): Economy of scale
(3): Increases reliability
What are the two types of multiprocessing? - ANSWER asymmetric and
symmetric ; splitting tasks, sharing tasks
What is dual-mode operation? (2 facts) - ANSWER (1): 2 modes: user mode
and kernel (aka: supervisor, protected) mode.
(2): Mode bit distinguishes between them, with only some instructions able to
be executed in kernel
What changes the mode to the kernel and back to user - ANSWER System call
changes to kernel, return changes back to user.
Match: Process / Program - active / passive entity - ANSWER Process =
Active
Program = passive
What does a process need when starting and terminating? - ANSWER
Starting: resources
ending: Deallocation of resources
For processes, what is the OS responsible for? (5) - ANSWER (1): Creating
and deleting user / system processes
(2) :Suspending and resuming processes
(3): Mechanism for process synchronization
(4): Mech for communication.
intermediary between a user of a computer and the computer hardware
What are the 3 main functions of an operating system? - ANSWER (1) manage
the computer's resources, such as the central processing unit, memory, disk
drives, and printers
(2) establish a user interface to make the system more convenient and solves
user problems
3) execute and provide services for applications software.
What two things does the OS do - ANSWER (1):Allocates resources and
schedules requests for fair and efficient use.
(2): Controls the execution of programs to prevent errors and improper use of
the computer
What does the kernel do? - ANSWER It is located in the heart of the operating
systems. It deals with low-level hardware operations. Runs at all times.
What is a bootstrap program? - ANSWER Loaded at power-up, initializes all
aspects of system, loads operating system kernel and starts execution.
How is a computer organized? - ANSWER -There are one or more CPUs
(cores or chips) and device controllers that connect via a shared bus to access
shared memory.
What does a CPU do with device controllers? - ANSWER Moves data to /
from buffers in controllers to / from main memory
What does a device controller do when completing an operation - ANSWER It
informs the CPU via an interrupt.
What is an interrupt? - ANSWER Signal from hardware or software indicating
that an event has occurred or that a process needs attention.
, What are interrupts caused by an error or user request, what generates them? -
ANSWER Trap or exception, software.
How are interrupts handled? - ANSWER (1)The execution is immediately
transfered to the handler
(2) OS preserves the CPU state by storing registers and program counter.
(3) handler takes action depending on the interrupt type.
What are the 3 advantages of multiprocessor systems? - ANSWER (1):
Increases throughput
(2): Economy of scale
(3): Increases reliability
What are the two types of multiprocessing? - ANSWER asymmetric and
symmetric ; splitting tasks, sharing tasks
What is dual-mode operation? (2 facts) - ANSWER (1): 2 modes: user mode
and kernel (aka: supervisor, protected) mode.
(2): Mode bit distinguishes between them, with only some instructions able to
be executed in kernel
What changes the mode to the kernel and back to user - ANSWER System call
changes to kernel, return changes back to user.
Match: Process / Program - active / passive entity - ANSWER Process =
Active
Program = passive
What does a process need when starting and terminating? - ANSWER
Starting: resources
ending: Deallocation of resources
For processes, what is the OS responsible for? (5) - ANSWER (1): Creating
and deleting user / system processes
(2) :Suspending and resuming processes
(3): Mechanism for process synchronization
(4): Mech for communication.
