Unit 2 (Rob) Flashcards
What are Device Drivers?
Device drivers are programs that lets the operating system communicate with specific computer hardware. Computer parts need a driver because they do not use standard commands.
What could Device drivers help when using different equipments?
- Device drivers could improve compatibility
- Enable devices to communicate with the operating system
- Identifies the hardware
- Translate program instructions
What are the benefits of GUI when children are using it?
GUI is generally more intuitive
There is less skill required to use it
Children can understand by looking at the images (icons) for younger kids that can’t read yet.
What are the benefits of using CLI to performance administrative and maintenance tasks?
- When doing tasks on CLI it can be carried out quick using a single or a few commands
- System doesn’t have a graphical interface so will not take much space on the computer’s HDD
- Requires less processing power and that may allow you to run background actions.
- Number of steps is reduced because you only need to set the commands.
Explain what’s an array and where is it stored
- An array is a data structure that has a fixed size, and a series of objects that are all the same type and size, each object inside an array is called an array element and all the elements stored in the array are stored in a contiguously memory (that means that they have no gaps between elements).
- An array is stored in adjacent memory locations and must be accessed sequentially
Explain what’s an stack
A stack is a data structure that can be imagined as a linear structure represented by a real physical stake or pile. Stacks are linear structures that can only be accessed in a FILO (first in last out) meaning that any data lower in the stack cannot be accessed directly and that means is not efficient for accessing records in a large database because it would not be easy to access the data in the lower stack as you would have to change some extra steps so would be hard for it to access specific data.
Explain what’s a queue
A queue is a data structure that is quite like a stack because you add new elements to the rear of the queue and elements leave from the front, queues are used in a variety of applications such as holding jobs waiting for to be run by the computer.
Explain what’s a kernel
Kernel is a computer program that is the core of a computer’s operating system, it controls over everything in the system of a computer, kernel’s primary function is to control and manage program execution, interrupts, modes, memory management, multi-tasking, disk access, file systems and device drivers, the kernel primary functions is to control and manage all these components and their tasks.
What is a user interface? and some examples
A user interface is when the user and the computer system interact with each other and that could be by inputs and software. An interface is a set of commands or menus where the user can communicate with a software. For example, a keyboard or a screen or the mouse on a computer is all part of the user interface
What are the types of HCI
The types of UI are GUI, CLI and Menu-based interface
What is disk defragmentation?
When files are deleted, some “free space” becomes available for reuse, these “free spaces” can end up being distributed across a drive especially if the files were small. If you then try to add a large file that is written to the drive then its data could be spread across different free spaces leading to file fragmentation, now // Defragmentation involves rearranging the information on a disk, so the files appear in a continuous sequence of “free spaces.” This improves file access times, most modern’s OS are already adapting this process, so it runs automatically
What is a file handler?
We handle a file whenever we delete it, or we save or we retrieve/load it and whenever we print a file, we are handling a file.
What is a file compression software? what is it used for?
This software helps us to “package” a file or files to use less space on a disk, this can also be known as “zipping up” the files or folders. It can be used whenever you want to transfer some data on a folder so you can zip it so it uploads faster.
What are hardware drivers?
Each time we install any new peripheral for example a new printer we need to load the print driver software associated with that device, and they are loaded on the hardware drivers, there are some small programs that tell the OS how to control them
Describe the purpose of an OS
The purpose of an operating system is to help the user when doing any tasks, for example any OS manages the computer’s memory and processes and also its software and hardware, it also lets you to have an interaction with its interface and this interaction is between the user and the hardware, without OS all computer systems are useless.
What are the different types of OS?
Single User OS, Multiprocessing OS, Multiuser OS and Real time OS
Explain what’s a single user OS
Is a type of OS that was developed with the intention of only one user using it at any given time and inside the single user OS usually is either single task or multitasking systems, a good example of Single user OS is when you want to have a basic single user OS at home only for yourself you would use that.
Explain what’s a multiprocessing OS
is a type of OS that was developed in order to help you do more things/tasks at once, so for example listening to music and writing an report.
Explain what’s a multiuser OS
Is a type of OS that allows two or more users to run any task/software at the same time from a central computer, some OS allow hundreds to even thousands of simultaneous users, usually multi-user OS are not computers is only 1 computer that is controlled by many different users, a perfect example of a multi-user OS is a supermarket checkout system.
Explain what’s a real time OS
Is a type of OS that was developed in order to help people on doing things in real time (milliseconds) for example gamers when they want to have advantage, they usually have a faster OS so everything they do on their input is done automatically to their PC, some advantages of using Real time OS is that it responds to input instantly.
Device Drivers features
Improves compatibility
Translates program instructions
enable hardware devices to communicate with the OS
it also allows the OS to identify the hardware/device that is communicating with the device driver
Identify kernel’s primary functions
Program execution Interrupts Modes Memory management Disk access Device drivers File systems Multi-tasking
Explain what is kernel’s job
Kernel’s job is to control and manage software, hardware and running tasks on the system
Kernel role in program execution
is that when a program wishes to perform an operation/instruction, this is sent to the kernel which then translates the program code to appropriate system calls, when provide the CPU and related hardware with the appropriate commands at the appropriate time to ensure instructions are carried out as intended by the program
Kernel role in interrupts
While Executing processes, there are conditions where tasks with more priority need to be handled first. In these cases, the kernel’s job is to interrupt in-between the execution of the current process and handle tasks with more priority which has arrived in between
Kernel Role in modes
The kernel job when we talk about modes is whenever a user wants to switch between user modes to run a app then the kernel will do that itself so for example if the user wants to open an app that only the other user has access to then the kernel will do that for the user, another thing that kernel does is that it also switch between kernel modes so for example if an application requires a low-level code that the OS needs for operations such as reading memory, then kernel will automatically change to kernel mode so it can do that.
Kernel role in memory management
Whenever a process is created and executed, it occupies memory, and when it gets terminated, the memory can be used again. But the memory should be handled by someone so that the released memory can be assigned again to the new processes. This task is also done by the Kernel. The kernel keeps track about which part of the memory is currently allocated and which part is available for being allocated to the other processes
What is time slicing kernel?
The kernel is responsible for controlling the process of “time slicing” which is a way that the computer creates the illusion of a single processor cannot execute more than one instruction at a time, so kernel’s job is to “slice” instructions into smaller pieces and dedicates processor cycles to executing these instructions.
Kernel role in multi-tasking
The kernel allocates enough CPU and peripheral time to every running program so work concurrently, it also schedules tasks (from one or more users) to the CPU, and it does “time slicing”.
Kernel role in disk access
The kernel read from or write to backing storage, the kernel also control which programs users can read/write to the disk and which data they have access to, this helps ensure security of the data and ensure data does not become corrupt due to being over written or accessed by an unauthorized program or user. The kernel will ensure that program instructions that require data to be written or retrieved from the storage disk are queued and/or given priority and then passed to the required disk location, hardware or program
Kernel role in file systems?
- Organizing data on the system ( controlling how it is stored and organized )
- Ensuring all the data on the system is stored on its appropriate format.
What is utility software
Utility software is software designed to help to analyse, configure, optimize or maintain a computer.
Examples of utility software
- Computer security such as antivirus, encryption, firewall, etc..
- File Management such as file managers
- Housekeeping such as back up and restore, memory checkers, etc..
- Disk handling such as disk cleaners, disk defragmenters, disk space analysers, etc…
What is application software
is a computer program designed to perform a task(s) or activities for the benefit of the user.
Examples of application software
Excel, Word, PowerPoint, all these are application software and they can be used for many different purposes, application software is any software that can benefit the user, such as excel that can be used by a restaurant to control cash flow.
What is utility software used for
It is used to support the computer infrastructure - in contrast to application software, which is aimed at directly performing tasks that benefit ordinary users.
