4 Software

Question 1

What is system software?

Answer 1

System software is software essential for the operation of the computer system and gives users a platform to run applications and carry out tasks. (Utility and Operating System)

Question 2

What is Utility Software?

Answer 2

Software designed to help maintain, enhance and troubleshoot/repair

Question 3

What are the 4 types of Utility Software?

Answer 3

• Defragmentation (Maintain)
• Compression (Enhance)
• Encryption (Enhance)
• Task Manager (Troubleshoot/Repair)

Question 4

Application software

Answer 4

Software chosen by a user to help them carry out a task (e.g. word processor, browser, email clients)

Question 5

Operating system (OS)

Answer 5

software that manages computer hardware and provides a platform for running apps

Question 6

What are the 8 main functions of the OS

Answer 6

1) File management
2) Handling Interrupts
3) User Interface
4) Peripheral management & device drivers
5) Memory management
6) Providing a platform for running applications
7) Providing system security
8) User management

Question 7

4 User Interfaces type

Answer 7

Command Line Interface (CLI) - allow users to enters commands by typing
Graphical User Interface (GUI) - requires users to interact using visual elements
Menu Interface - requires users to select options that lead to further sub-menus
Natural Language Interface (NLI) - uses spoken words to respond to verbal/textual inputs from the user

Question 8

Device Drivers

Answer 8

A piece of software used to control a piece of hardware. Peripherals require device drivers for the OS to use it.

Question 9

How application software, operating system, and hardware interact

Answer 9

• Application software communicates with the operating system, this allows it to interact with the hardware
• The hardware processes and sends the information to the OS, which interacts directly to the application system
• process is repeated while application software is in use

Question 10

Firmware

Answer 10

• Software embedded directly in to the hardware of a device
• permanent software programmed into ROM (mark scheme)
• It provides the boot-up instructions contained in the bootstrap loader, handled by BIOS during start up (firmware)

Question 11

Interrupts

Answer 11

Signal for the CPU to stop what it is currently doing and do something else as a higher priority (ensures urgent tasks are dealt with immediately)

Question 12

Describe how the processor handles and executes an interrupt

(11 mark scheme points)

Answer 12

1) Interrupt is given a priority and placed in interrupt queue

2) The processor finishes its current FE cycle of the program

3) Processor checks the interrupt priority queue; if lower priority, the processor runs the FDE cycle for program & if higher priority, the processor stores the current process on a stack (reserved area in RAM)

4) The appropriate ISR is called based on the sources of the interrupt, and the ISR handles the interrupt

5) If there is another higher priority interrupt than the process, then it’s repeated, otherwise the processor retrieves contents of the stack

Question 13

Examples of hardware interrupts (Name at least 3)

Answer 13

• pressing power button
• moving the mouse
• “out of paper” message (printers)
• clicking an icon to open a new program
• keyboard presses
• low battery warning on laptop

Question 14

Examples of software interrupts (Name 2)

Answer 14

• a program is not responding
• division by zero
• timer interrupt
• 2 processes accessing the same memory location

Question 15

What are low-level languages

Answer 15

languages that directly translates to machine code understood by the processor (machine dependent)

Question 16

First generation

Answer 16

Machine code (instructions are directly executable by the processor)

binary code

Question 17

Second generation (low level)

Answer 17

Assembly code and is translated by an Assembler

Question 18

Advantages of low-level languages

Answer 18

• Complete control over the systems components
• Occupy less memory & execute faster
• Direct manipulation of hardware
• Less storage used in RAM

Question 19

Disadvantages of low-level languages

Answer 19

• Difficult to write & understand
• Machine dependent
• More prone to errors

Question 20

High-level language

Answer 20

uses english-like statements

machine independent

Question 21

Advantages of high-level language

Answer 21

• easier to read & write
• easier to debug
• One line of code can perform multiple commands

Question 22

Disadvantages of high levels languages

Answer 22

• Needs to be translated to machine code before running (time-consuming)
• The user can’t directly manipulate hardware

Question 23

Why do people use assembly language?

Answer 23

• Making use of specific hardware
• Complete machine dependent instructions
• ensure that RAM is not being used too much
• For code to run faster and more efficiently

Question 24

What is a translator

Answer 24

A program that translates program source code into machine code so it can be executed directly by a processor

Question 25

What is an interpreter?

Answer 25

An interpreter reads the code line-by-line, and if it finds an error it will stop immediately & display it to the user

Question 26

Advantages of an interpreter

Answer 26

- Stops when it finds a specific syntax error in the code - easier to debug - requires less RAM to process the code

Question 27

Disadvantages of an interpreter

Answer 27

- Slower execution - Every time the program is run it has to be translated - Source code is always required

Question 28

What is a compiler?

Answer 28

A compiler translates high-level languages into machine code all in one go by creating an executable

Question 29

Advantages of a compiler?

Answer 29

- Fast execution - Optimises code for better performance - Only need the executable for running the code

Question 30

Disadvantages of a compiler?

Answer 30

- Compilation takes time before running - Errors are shown all at once so its hard to debug - Must recompile when there is errors and for different systems

Question 31

What is an Integrated Development Environment (IDE)?

Answer 31

It is a software designed to make high-level languages more efficient and allows programmers to write, test, and debug code.

Question 32

What are the features of an IDE?

Answer 32

Editor - gives users the environment to write, edit, and maintain high-level code -> Basic code formatting tools -> Prettyprint (colour) -> Code editing -> Commenting Code Error diagnostics - tools that help to identify, understand and fix errors Run-time environment Translator - Built in to compile/interpret code

Question 33

What is file management?

Answer 33

A process carried out by the OS creating, organizing, manipulating and accessing files and folders on a computer system (manages where data is stored in primary & secondary storage)

Question 34

Explain handling interrupts

Answer 34

The OS need to handle and process interrupts quickly (interrupts events need immediate attention of the CPU)

Question 35

Peripheral management & device drivers

Answer 35

- manages the way peripherals (hardware) interact with the software - allows PnP, automatically detecting and configuring new peripherals - OS allocates system resources to peripherals to ensure efficient operation

Question 36

What is software?

Answer 36

The set of instructions or programs that tell a computer what to do and enable it to perform specific tasks

Question 37

Memory management

Answer 37

- OS allocates RAM between different programs (is responsible for copying programs/data from secondary to primary storage when needed) - make sure memory is used efficiently - make sure 2 processes don't try and access same memory location - creates a memory partition and virtual memory - Multitasking is when the OS simultaneously manages system resources based on priority

Question 38

Providing a platform for running applications

Answer 38

it allows application to run by managing hardware and giving programs/software to access system resources (CPU, memory, storage, I/O)

Question 39

Providing system security

Answer 39

- restricts system accounts from performing certain actions - firewall, virus scanning, file encryption, password protected accounts etc.

Question 40

User management

Answer 40

- process of OS enabling different users to log onto a computer - able to maintain settings for individual users

Question 41

What is the ISR?

Answer 41

Holds instruction that will need to be fetched, decoded & executed to complete the commands of the interrupt

Question 42

Advantages & Disadvantages of CLI (Command-Line)

Answer 42

- Uses less system resources - Useful for automation of tasks ------------------------------------------------------------------------------- - Requires users to remember commands - Typing errors & less intuitive than GUI

Question 43

Advantages & Disadvantages of GUI (Graphical User)

Answer 43

- Intuitive & user friendly - Easy to understood -------------------------------------------------------------------------------- - Uses more system resources - Can be slower to find & execute commands