1.2.2 Applications Generation

Question 1

Applications Software

Answer 1

() Performs one specific task
() Requires systems software to be able to run

Examples: Word processing, spreadsheets, web browsers

Question 2

Systems software

Answer 2

() Manages computer resources
() Ensures consistently high performance

Examples: Utility programs, operating system, device drivers

Question 3

Officially recognised application packages:

Answer 3

Word Processor
Database software
Presentation software
Email software
Graphics manipulation
Web browser

Question 4

Utilities

Answer 4

() Maintains high-performing operating system
() Each utility has a specific function

Question 5

Utility examples

Answer 5

Compression
Disk Defragmentation
Automatic Updating
Automatic Backup

Question 6

Open source vs Closed source defintions

Answer 6

Open source:
() Can be used without a licesnce
() Distributed with source code

Closed source:
() User must hold correct liscense
() Users cannot access source code

Question 7

Closed source vs open source eval

Answer 7

Open:
+ Improved on by community effort
+ No restriction for users
- Inadequate support (No user manuals)
- Lower security

Question 8

Compiler

Answer 8

() Translate all at once

+ Can be run without translator
- Initial process is longer

Question 9

Interpreter

Answer 9

() Translate and execute line by line
() Produce error if a line contains an error

+ Useful for testing
- Slower

Question 10

Assembler

Answer 10

Assemlby code:
() Translate assembly code into machine code

Question 11

Translators

Answer 11

Convert source code into object code

Question 12

Stages of compilation:

Answer 12

Lexical Analysis:
() Keywordws and identifiers are replaced with tokens
() Information about tokens is stored in token table
() Whitespace and comments removed

Syntax:
() Errors are flagged
() Tokens are analysed against rules of programming
() AST produced

Code generation:
() Create OBJECT CODE using AST

Optimisation:
() Redundant parts are removed
() Aims to reduce execution time

Question 13

Linkers:

Answer 13

Software that links moduales and libraries included in the code

Question 14

Static vs Dynamic linking

Answer 14

Static:
() Code is coped directly into file
() Combined at compile time

Dynamic:
() Addresses of modules are added to the file
() Combined at run time

Question 15

Loaders

Answer 15

Programs provided by operating system
Fetches the module from the given memory location

Question 16

Library Adv

Answer 16

() Error-free
() Save time and effort
() Can be reused