System And Application Software ! :beer_mugs:
System And Application Software ! :beer_mugs:
1.System software - e.g. computer programs, such as Operating system, utility programs and drivers
Application software - e.g. user programs, such as Microsoft Office, graphics package and web browsers
- used to control hardware + coordinate other systems software as well as manage applications software
- used to perform often repeated tasks e.g. data compression, file backup, archive software and disk fragmenters
- used to perform task needed by several other pieces of software e.g. Dynamic Link Library Files
- used to convert programs written by the user into executable form
Functions of an OS
- Providing input and Output to the User
- Allocating and keeping track of memory for programs and data.
- Transfer of data to and from secondary storage from memory.
- Managing input/output and storage devices.
Multi - Tasking
- Allocating processor time slices for each task running in memory.
- Managing user accounts/passwords/ access levels.
- managing task priority whilst multi- tasking.]
- To prioritize system requests/interrupts and manage error handling
2:5:2 - Constable Bekah, Ellie, Arlene
The operating system will ensure that the requirements of the various users are balanced, and that each of the programs they are using has sufficient and separate resources so that a problem with one user doesn't affect the entire community of users.
use of resources are monitored and a log is kept.
A multi-user operating system must allow more than one person to share a computers resources at the same time.
-one method of implementing a multi- access system is by allocating a period of processing time to each user. a process can be carried out during this time.
this speed is faster than any other components meaning CPU can carry out processing for 1 program then switch attention
multi-tasking allows for this because of processor speed
executing tasks simultaneously
often run several tasks at once
in fact is automatically - switching between tasks -allocating resources - keeping track of task locations
there are 2 types:
PRE-EMPTIVE - OS uses criteria to decide how much time to allocate to each task
CO-OPERATIVE - OS never initiates context switch from a running process to another process :fire:
Single User OS - allows access to the computer for any one user at any one time
single user, multi-tasking
allows the user to have a number of programs running at any one time. In reality only one application can be run at any specific time
a scheduler determines the sequence that processes are executed
Single user, single task
the user can do one thing at one time :fire::fire::fire::fire::fire::fire:
:beer_mugs:beer_mugs:beer_mugs :beer_mugs :beer_mugs:
2.5.9 Open Source VS Proprietary
Proprietary software is software that is owned by an individual or a company (usually the one that developed it). There are almost always major restrictions on its use, and its source code is almost always kept secret.
Limits imposed upon use
The person responsible for the development of the application maintains exclusive control over it.
Only original authors can:
copy the application
view the source code
make any modifications
subsequent users must sign a license agreement to show they agree to use the application within the bounds originally set down by the authors of the application.
Example of proprietary software:
Microsoft double glazed Windows
Open Source Software:
Allows the user to adapt the software to their specific needs.
Examples of Open Source Software:
- Firefox, Gimp, Open Office
- C, C++, Mono, PHP, Python, Perl, Ruby, TcL
- Ubuntu OS made from Linux.
Source code that has been edited and redistributed must be, by license, free to use.
Source code is readily available for other users to edit and redistribute the software.
The user can fix bugs in the code themselves instead of relying on the original developer.
utility programs :fire: :fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire::fire:
a utility program is a systems program that preforms a specific task related to the management of computer functions . A utility program may be designed to do one or two tasks well and nothing else e.g
file back, data compression, archive software and disk defragments
compression software software stores data in a format
2.5.8 Explain Software Delivery
Downloading to a Device
User is guaranteed access at anytime
Access not dependant on an appropriate broadband link the next time you wish to access it
the application requires space on the devices backing storage
EG Daily Mail App
Accessing over the Web
EG Google Apps
Often referred to as cloud storage
Little consideration needs to be given to the storage capacity of the accessing device
issues with the users broadband can impact upon the availability of the application