2 Operating Systems Flashcards
What is an Operating System (OS) ??
An OS is what co-ordinates all the operations of your computer. It manages all the resources on the computer such as the CPU and RAM and controls the software and hardware. Without an OS your computer, phone or device would be useless.
Real Time OS is…
Real Time OS- an operating system that processes inputs and responds to them instantaneously.
This OS provides a fast response to an input and is best used where an instant form of output or feedback is needed after the input being processed e.g., a traffic light or a warning light on a car dashboard.
Single User Single Task OS is…
Single User Single Task OS-A Single User single-tasking operating system allows only one user to perform only one or single task at a time.
Simple hand held games such as virtual pets or childs toys would use a SUST OS. They cannot handle running multiple applications at once
Single User Multi-Tasking OS is…
Single User Multitasking OS-A Single-User Operating System is a system in which only one user can access the computer system at a time.
An office worker using a laptop/macbook as they can quickly switch between applications or use multiple apps at the same time e.g. typing up letters on word and listening to music and emails being bulk sent.
Multi User OS is…
Multi-user OS- A Multi-User Operating System is a system that allows more than one user to access a computer system at one time.
A school or large office would be an example, allot of pupils or employees can share the resources such as printers and log on or use their accounts on multiple devices.
What 5 roles do the OS perform?
- Networking
- Memory Manangement
- Security
- Device Drivers
- Multitasking
OS has 5 roles- describe “Networking”…
OS’s simplify networking on a computer. The OS implements a number of networking technologies such as
* TCP/IP stack
* Network utility programs such as traceroute (traceroute allows a user to see where data packets travel to help diagnose problems)
* Device drivers for the network interface card
OS has 5 roles- describe “Security”…
Several features are commonly built into a computer OS to help improve the security of the device which include;
* user authentication (username and passwords)
* antivirus and firewall software
* backup facilities
The OS manages and runs these features to keep the device secure.
OS has 5 roles- describe “Device Drivers”…
An OS comes with generic device drivers that will work with a variety of peripheral devices (keyboards, USBs, Mice, Joysticks etc.) allowing them to communicate with your computer. However most peripheral devices come with specific drivers to take advantage of the devices capabilities and the OS must install these drivers to take advantage.
Think about the next time you plug a USB in, you will sometimes notice a little pop up notice bottom left saying installing driver, or USB recognised. This picture shows the OS could not install therefore recognise the driver of the USB so it will not work.
OS has 5 roles- describe “Memory Management”…
The OS manages the computers resources such as memory. To do this the computer must decide and track;
* which processes and tasks to allocate memory to
* how much memory to allocate to each task/ process
* when to un-allocate memory
* transferring data to the page file on the HDD temporarily to free RAM (makes the computer faster and more efficient)
OS has 5 roles- describe “Multitasking”…
Most OS’s allow you to run more than one application at a time. To do this the OS must be able to allocate resources such as memory, disk space, CPU to each of the tasks/applications in order to allow it to complete two tasks simultaneously.
Think about using a computer/ laptop. You can type up a word document while listening to music on Spotify and have open your facebook account on Safari/ GoogleChrome. This is multitasking, managed by the OS. Ctrl+Alt+Del will allow you to get the Task Manager which demonstrates multitasking.
What factors can effect the performance of an OS?
- Limited CPU
- Limited RAM Capacity
- Number of Cores
- Slow Hard-disk read/write speeds
- Virtual Memory factors- Not enough HDD space allocated to extend the RAM can slow down the operating system abilities to perform its role. Heavy use of virtual memory relies on slow disc transfers rather than the very fast working memory (RAM) data transfers.
- Malware- Having viruses, worms or spyware on a computer can have a serious effect of the OS’s performance by slowing it down or restricting its ability to carry out its role.
