Explain what an operating system does.

An operating system has three primary functions. One, it manages a computer’s resources such as the CPU, memory, storage devices, and other peripherals. Two, it establishes a graphical user interface or GUI for easy user interaction. Three, it provides a platform for executing software applications, most of which is controlled by user input.

How does the OS manage the processor?

When you execute a task on your computer, the CPU is performing multiple calculations. To provide this seamless multitasking, the OS manages the timing (interrupts) of tasks the CPU works on. The OS coordinates the tasks of the CPU, uses RAM as temporary storage for instructions and data, and provides the required CPU outputs to the appropriate applications.

What activities are coordinated by the OS?

All activities between the computer hardware, application processing, and physical user interaction is coordinated and controlled by the operating system. For example, if a user is typing a document in Microsoft Word, the operating system detects the user inputs on the keyboard, passes the inputs to the application, the CPU performs any required computations, and system RAM is utilized to store temporary data.

How does the OS manage the computer’s memory?

When an application is launched, all or parts of the program are loaded into RAM for quick access to the operating system, CPU, and required hardware. The OS manages this process. To reduce memory utilization, parts of the application are only loaded into RAM when called. This process is called dynamic loading.

What is virtual memory and how does it work?

Computers have a finite amount of RAM, and sometimes, all of that memory gets used. In this case, virtual memory is used by the operating system to compensate for a shortage in physical memory by temporarily using a portion of physical disk space. In the Windows operating system this is known as the ‘Page File.’ In Linux this is referred to as “Swap Space.” As RAM has become increasingly more affordable over the past decade, the need to utilize virtual memory has steadily decreased.

How does the OS manage peripheral devices?

Peripheral devices refer to almost anything that plugs into your computer. This could be a mouse, keyboard, microphone, monitor, printer, or speaker. The operating system manages these devices in much the same way it manages the CPU and RAM, except some of these peripheral devices are used as inputs, and others are used as outputs. Earlier I used an example of a user typing a Word document with a keyboard. A keyboard would be an input device, or a device that is used to give a computer instructions. A printer on the other hand would be an output device, or a device that receives instructions from the computer.

What are device drivers?

In order for a peripheral device to accomplish its specific task, it must properly communicate with the operating system. For example, when you plug a keyboard into the USB port on your computer, you expect the computer to recognize that device as a keyboard and allow you to type with it. The computer uses a sets of files called Drivers that instruct the operating system on how that piece of hardware operates.

What is PnP?

PnP refers to “Plug and Play,” or an operating system’s ability to automatically install device drivers when a device is plugged in. Over the years, Windows has steadily improved at this, however, there are still significant shortcomings.

How does the OS coordinate software?

Most people refer to software as programs they have intentionally installed on their computers. The operating system allows users to access software through the GUI and outputs relevant information on a monitor. In the background, the operating system loads required parts of the software in RAM, and sends instructions to the CPU for processing. The operating system also coordinates peripheral inputs and outputs with specific application tasks such as printing and scanning.

What is the BIOS?

BIOS stands for Basic Input/Output System.

What does the BIOS do?

The BIOS is a non-volatile firmware that initializes system hardware and checks for basic operation and errors in a pre-boot environment. The BIOS is also responsible for configuring boot device priority for launching the initial boot loader of an operating system.

What is POST?

POST, or “Power On Self Test” is a diagnostic procedure conducted by the BIOS in the pre-boot environment. POST evaluates the computer system for basic hardware installation and functionality. The CPU, RAM, keyboard, and video card(s) are examples of several hardware components tested.

What is the kernel?

The kernel is an essential part of the operating system responsible for memory management, CPU and task management, and disk management. The kernel is usually loaded and stored in a protected area of RAM and directly interfaces with system hardware, device drivers, and core applications.

What are beep codes?

Beep codes are diagnostic audio outputs from the POST process. These beeps are similar to Morse Code and are output to a speaker on the motherboard. Technicians can then use these unique codes to troubleshoot and diagnose hardware problems with the computer system.

What are three different operating systems (note – only one can be Microsoft)?

Microsoft Windows, Ubuntu Linux, and Android OS.

Which operating system would you recommend?

All three of the above operating systems are inherently different and have different use cases. Ultimately, I would recommend using all three, but again, this is dependent on each use case.

Why?

Microsoft Windows is a robust operating system that runs on x86 and x64 architecture, has a friendly GUI, and supports a vast array of software for residential and business users. Even after decades of development, Windows still struggles from memory leaks and needs constantly rebooted. While Ubuntu doesn’t struggle with the same memory leak issue, it has a less user friendly GUI with limited software support for the average user. Android OS is a lightweight Linux OS that is designed to be run on lower powered ARM processors. All three operating systems work well for their intended audience, but are significantly limited when used outside of that capacity.

References

Virtual Memory | Operating System. (n.d.). Retrieved March 12, 2019, from https://www.geeksforgeeks.org/virtual-memory-operating-systems/

What is BIOS (Basic Input/Output System) (2019, February 27). Retrieved March 12, 2019, from https://www.computerhope.com/jargon/b/bios.htm