Hardware and Software

Question 1

what is an operating system

Answer 1

a program that acts as a bridge betweeen a user of a computer and the computer hardware

Question 2

what are the purposes of an operating system?

Answer 2

• manages hardware
• manages the applications installed
• creates a user interface
• provides a layer of security

Question 3

what are the types of user interfaces

Answer 3

• command line - shell responding to successive commmands
  
  • GUI -use icons and other visual indicators to issue commands

Question 4

what are the four functions of an operating system
?

Answer 4

• processor scheduling
• backing store management
• memory management
  
  • peripheral management

Question 5

explain memory management

Answer 5

• program needs to be loaded into RAM
• OS controls the allocation and management of RAM
  
  • if there is no free space virtual memory is used

Question 6

explain backing store management

Answer 6

OS mantains records of all files stored in secondary storage including information like their location and what user can access what

Question 7

explain processor scheduling

Answer 7

OS controls which programs can send data to the processor to be processed

Question 8

explain multi-tasking

Answer 8

processor executes 1 process at a time but allows multiple applications to run by rapidly switching between processes

Question 9

what are the types of schedulers and explain

Answer 9

• round robin - each process is given a slice of processing time
  
  • shortest job first

Question 10

Explain peripheral management

Answer 10

• OS uses device drivers which are programs that convert between the peripheral signals and the OS signals
  
  • driver is the interface hiding the complexities of the hardware

Question 11

what are the types of software

Answer 11

system software and application software

Question 12

what are the types of application software

Answer 12

• special purpose
• general purpose
• off the shelf
  
  • bespoke

Question 13

explain special purpose software

Answer 13

performs a task for a single specific job e.g. payroll, media playhers, calendar programs

Question 14

explain general purpose software

Answer 14

performs a range of generic tasks e.g. word processor, spreadsheet software

Question 15

explain bespoke software

Answer 15

softwaare which is created to fulfil exact specifications

Question 16

explain off the shelf software

Answer 16

it is a type of special purpose software which is readily available

Question 17

what are the drawbacks of off the shelf software

Answer 17

• you have little or no control of the features
  
  • it may not do exacty what you want

Question 18

what are the benefits of off the shelf software

Answer 18

• readily available
• cost is cheaper
• likely to be well tested

Question 19

what are the benefits of bespoke software

Answer 19

• fulfils exact specifications, you have complete control over functionality

Question 20

what are the disadvantages of bespoke software

Answer 20

• may take a long time to produce
  
  • signifcant increase in price

Question 21

what are the types of system software

Answer 21

• Library programs
• Utility programs
• Translators
• Operating system

Question 22

what is system software

Answer 22

required to run and manage the computers hardware and application programs

Question 23

what is utility software

Answer 23

designed to analyse configure or mantain a computer system e.g.

• disk defrag
  
  • virus checker

Question 24

what is a library?

Answer 24

it is a collection of precompiled routines that can be used by other programs e.g. python has random and math

Question 25

what is a translator?

Answer 25

it is used to translate code written in assembly language or high level languages into machine code

Question 26

define machine code

Answer 26

instructions comprised of pure binary, low level language

Question 27

what are the three types of translators?

Answer 27

* compilers * interpreters * assemblers

Question 28

what does a compiler do?

Answer 28

translates high level language into an executable binary file which can be run without source code

Question 29

what does an interpreter do

Answer 29

translates high level langauges into machine code one line at a time immediately executing the instruction

Question 30

what does an assembler do

Answer 30

it converts assembly code into machine code

Question 31

point about low level languages

Answer 31

* has the least abstraction (executed directly) * not portable as it corresponds to specific processor instruction set * requires less system resources, useful in embedded systems

Question 32

points jabout high level languages

Answer 32

* understandble as it is close to english and math * portable * more abstract

Question 33

define imperative high level language

Answer 33

consists of commands for the computer to perform

Question 34

define declarative language

Answer 34

focuses on what the program should do without listing how

Question 35

what is byte code

Answer 35

program code that has been compiled from source code into low level code designed for a software interpreter

Question 36

what is an API

Answer 36

an application programming interface that hides the commplexities of the operating system