1.2.1 OS

Question 1

What is a multi-tasking operating system

Answer 1

running multiple programs apparently simulatenously

Question 2

What is a multi-user operating system

Answer 2

Allows more than one user to access a computer’s resources at one time.

Question 3

what is a distributed operating system

Answer 3

Allows multiple computers to work together as a single system

Question 4

What is an embedded operating system

Answer 4

Built into a device, oftern with limited resources.

Question 5

What is a real-time operating system

Answer 5

Guaranteed to carry out actions within a given period of time.

Question 6

what is a virtual machine?

Answer 6

A program that has the same functioinality as a physical machine.

Question 7

Why would you use a cirtual machine to run different operating systems.

Answer 7

• A program could be OS specific

- you may be developing an app for different platforms(OS)

Question 8

What is itermediate code

Answer 8

it is a compromise between compiled and interpreted programs. It is an efficient representation of the source code.

Question 9

What are the advantages of intermediate code with virtual machines

Answer 9

• any device with the virual machine software can run the program
• Programs are very portable between system types.
• source code not visable

Question 10

What is the functions of an operating system?

Answer 10

• Manage hardware
• Manage programs being installed and run,
• manage the security of the system
• provide an interface between the user and the computer

Question 11

State functions of an OS.

Answer 11

• memory management
• provide a user interface
• manage hardware/peripherals
• manage CPUI usage / handles interrupts
• providing secuirty
• provide platform to run other software
• provide utilities for system maintenance.

Question 12

State the name of the type of memory management used to diuvide memory into equally sized chunks.

Answer 12

Paging

Question 13

Describe how the operating system would use virtual memory to load program C.

Answer 13

• Os uses area of secondary storage as virtual memory
• move unused pages / parts of other applications into virtual memory.
• loads program C into (physical) memory.

Question 14

Explain why using a risc processor rather than a cisc processor is likely to result in increased battery life.

Answer 14

• RISC has a smaller instruction set than CISC.
• RISC has less tranisters than CISC
• means less power is reqiured.

Question 15

define the term embedded opperating system

Answer 15

system software/ software used to manage the device,
which is built into the device itself
stored in the device’s ROM
specific to the hardware / purpose

Question 16

What is the kernel and what is its purpose.

Answer 16

Ther kernal is the core of the OS,

• managing system resources
• scheduling processor time
• sending/receivig data from device

Question 17

What does memory management ensure?

Answer 17

• adequate RAM is allocated
• That programs do no interfere with each other’s use of memory
• Program sharing of RAM is controlled for secuity reasons
• memory is used efficiently.

Question 18

What is segmentation

Answer 18

The splitting of a program into logical coponents

Question 19

What is paging

Answer 19

splitting a program into blocks of the same size

Question 20

What is virtual memory

Answer 20

The use if secondary storage as an extension of the computers physical memory.

Question 21

What is a scheduler?

Answer 21

A program that manages the amount of time different processes have in the CPU.

Question 22

Name the 5 scheduling algorithms

Answer 22

• round robin
• First come first served
• shortest job first
• shortest remaining time
• multi-level feedvack queues.

Question 23

What is an interrupt

Answer 23

Different devices and processes may need the processors attention at various times, they signal the processor for attention via an interrupt.

Question 24

What data structure is used while interrupts are being serviced

Answer 24

A stack

Question 25

What is the purpose of BIOs

Answer 25

• check hardware components are functioning

- When complete a boot leader begins to load the operating system into memory.