1.2.2 Applications Generation Flashcards
1.2.2 A)
What are the natures of software
Software can either application software or system software.
1.2.2 A)
What is system software
system software is low level software that is responsible for running the computer system smoothly interacting with hardware providing a platform for application software to run.
Example: utility programs, OS , device drivers
1.2.2 A)
What is Application software
designed to be used by the end user to preform one specific task. app software needs system software
Example : word , spreadsheet
1.2.2 B)
Define utility
piece of system software that ensures consistent and high performance from the OS .
1.2.2 B)
What are examples of utility
Compression
Disk defragmentation
Anti-virus
Auto-updating
Backup
1.2.2 B)
What are examples of utility
What is compression
Enable files to be compressed and decompressed used to send large files
1.2.2 B)
What are examples of utility
What is disk defragmenation
as disk becomes full, slow r/w cos files are fragmented. This rearranges content so faster to r/w . ^ performance
1.2.2 B)
What are examples of utility
What is antivirus
Detects potential threats to the computer
1.2.2 B)
What are examples of utility
What is auto updating
ensure OS is up to date. tracks bugs / security flaws makes device less vulnerable.
1.2.2 B)
What are examples of utility
What is backup
automatically creates routine copies of specific files selected by user meaning recovery.
1.2.2 C)
What is source code and object code
whats the difference
soruce code is object code before its translated - high level
object code is source code after its translated - low level
1.2.2 C)
Define open source
can be used by anyone w/o license
1.2.2 C)
Define closed source
requires license can be access source code company owns rights.
1.2.2 C)
Adv / DAdv of open source
Adv ) modify / improve by anyone , support from community , modified and sold on.
DAdv ) online support may be wrong , lower security
1.2.2 C)
Adv / DAdv of closed source
Adv) well tested updated , expert support, ^ level security
DAdv) license is restricting, user cannot modify and / or improve
1.2.2 C)
How to know weather open or closed
Suitability of the software to the task it will be used for,
cost: maintenance/ staff/ licence, functionality - ease of use
1.2.2 D)
What is a translator
program that converts high level source code into low level object code
1.2.2 D)
properties of a compiler
Translates all at once
Shows errors at the end
Needs to be recompiled when changes made
initially longer then interpreter and assembler
complier code is specific to a processor type
used to produce intermediate code
1.2.2 D)
properties of an interpreter
translates and executes one line at a time stops at error
may be faster but slower at running compiled code
used for testing sections of code don’t need to run all
more portable
1.2.2 D)
properties of an assembler
low level language next up from machine code
platform specific
instructions used is dependant on Instruction set
assembler translates assembly code into machine code
1 line of AC is almost 1 line of MC so almost 1 to 1
1.2.2 E)
What are the stages of compilation
1) Lexical analysis
2) syntax analysis
3)code generation
4)optimisation
1.2.2 E)
What are the stages of compilation
What happens at lexical analysis
white spaces and comments removed
remaining code analysed for keywords
also variables and contestants
these are replaced with token
information about these stores in symbol table
1.2.2 E)
What are the stages of compilation
What happens at syntax analysis
tokens are analysed against grammar and rules of lang
any breaking rules are flagged
abstract syntax tree produced ( code in a tree)
more details abt identifiers added to symbol tree (data type / scope / address)
semantic analysis logical errors detected
passes code to code generation
1.2.2 E)
What are the stages of compilation
What happens at code generation
Abstract tree produced in syntax analysis is used to produce machine code
1.2.2 E)
What are the stages of compilation
What happens at optimisation
aim to make code faster to execute. reduce time taken for compiler redundant code is removed
1.2.2 F)
What’s a linker
responsible for linking external modules and libraries within code
1.2.2 F)
What are the two type of linkers
static and dynamic
1.2.2 F)
What is a static linker
whats the -ve of working this way
(subroutine) Modules / libraries added directly into main file , ^ file size , external update wont effect program
1.2.2 F)
What is a dynamic linker
whats +ve of working in this way
Address of modules (subroutine) / libraries included in file . loaders retrieve program from specific address. file remains same size
1.2.2 F)
What is a loader
when files execute loaders retries the library/ subroutine (modules) from memory
1.2.2 F)
What is a library
Pre-complied programs. ready to use, save time reusable using linkers
