Hardware And Software Flashcards
Hardware
Hardware describes the electrical or electro-mechanical parts of a computer system
These comprise the physical, tangible parts of the computer and its input, output and storage devices
Software
Software comprises all of the programs that make the computer function
2 types of software
System software
Application software
Types of system software
Operating systems
Utility programs
Library programs
Translators
Types of application software
General purpose
Special purpose
System software purpose
System software is required to run and manage the computer’s hardware and application programs
Examples of system software in action
- allocation of jobs to processor
- peripheral management
- maintaining security and checking for viruses
- program code to machine code
Role of Operating system
serves as a middle-man for communication between the computer’s hardware and software
Examples of OS
Windows
Mac OS
Linux
Android
Utility software
Some utility software is designed to analyse, configure,optimise or maintain a computer system
Additional common tasks performed by utilities
Virus checkers
Automatic backup and restore
File compression software
Libraries
A library is a collection of pre-compiled routines that can be used by other programs
What is machine code
Machine code is the lowest level of instruction comprising pure binary
- All computer instructions need to be converted into machine code
what is a translator
A translator is used to translate code written in assembly language or other high level code into machine-code
what are the 3 types of translators
Assembles
Compilers
Interpreters
Assembler
translate assembly language into machine code
Compilers
translate high-level language programs into object code (machine code) which can be saved and run whenever needed, without the compiler having to be present
Interpreters
also translate high-level language programs – more detail in another lesson
Examples of application softwares
Word processors
Image editors
Accounting packages
Internet browsers
Email clients
4 categories of application software
General purpose
Special purpose
Off-the-shelf
Bespoke
General purpose software
Can be used for a range of tasks
Examples of general purpose software
Word processors – for letters, posters or textbooks
Graphics packages – for image retouching, photo editing or drawing diagrams
Spreadsheet software – for modelling, creating tables of data or lists
Special purpose software
Performs tasks for a single, specific job
Examples of special purpose software
Payroll or accountancy software
Media players
Calendar programs
Online payment systems
Off-the-shelf software
Benefits
Off-the-shelf software is readily available for anyone to use
The cost is usually lower because development costs are shared among all the buyers
It is likely to be well-documented and well-tested
Off-the-shelf software
Drawbacks
You have little or no control over what features there are
It may not do exactly what you want
Bespoke software
Created to fulfil your own exact specs
Bespoke software
Drawbacks
High cost
Long time to develop
OS - memory management
The os allocates memory to different processes when multiple are running at the same time
OS - What is processor scheduling
The os controls which programs can send data to the processor to be processed
The processor executes small parts of each operation in turn so that programs appear to run simultaneously
This is known as multi-tasking
The scheduler
Is the operating system module responsible for ensuring that processor time is used as efficiently as possible
3 different scheduling algorithms
Round robin - each process in turn has use of the processor for a given time slice
Shortest job next
Priority system
Backing store management
The OS keeps track of where all files are stored on hard disk or external drives and where space is free to be used if the user performs a save operation
