Exercises: What the operating system is used for

Explain in your own words what the operating system of a device is and write down the name of the operating system of your cell phone or computer, along with two things that this system allows you to do.

Imagine a computer without an operating system: just the case and components. Could you play a video game on it? What about writing a piece of schoolwork? Reason your answers, explaining what is missing.

The diagram shows the layers of a computer, from the person using it to the machine, but an intermediate layer is covered with a question mark, as shown in the diagram.

Which layer is missing from the diagram? Explain what that layer does and reason why applications do not communicate directly with the hardware.

The operating system works without you noticing. Name three tasks it performs for you in the background (managing memory, displaying battery alerts, keeping time, controlling who logs into the device...) and explain one of them in a single sentence.

Order these four words from the person to the machine, in the way they communicate with each other: hardware, application, operating system, user. Explain in one sentence what each link in the chain does.

Explain the difference between shutting down ('apagar') and sleeping ('suspender') a computer: what the operating system does with your open documents in each case and when it is best to use each option.

When you drag a file to the recycle bin (or trash), who actually moves it: you, the open application or the operating system? Reason your answer thinking about who controls the device's folders.

When you plug in a USB flash drive, the computer recognises it almost instantly and displays its icon. Explain what the operating system does in those few seconds (detecting the device, loading its driver, displaying it to the user) and why you do not need to install anything manually.

You click 'print' in the word processor and, a few seconds later, the printer starts working. Describe the full chain of who communicates with whom (application, operating system, hardware) and explain two specific tasks performed by the operating system at that moment.

You can listen to music while typing a document with your web browser open. Explain in your own words how the operating system manages to make all applications share the CPU and memory without 'clashing', and what you notice when you open too many at once.

The operating system organises files into folders. Your 'Documents' folder is a mess of schoolwork, photos and downloads. Design a folder structure to organise everything for the school year, write down the rules you followed (clear names, subfolders by subject...) and explain what advantages it will have by June.

While copying a very large file to a USB flash drive, you continue browsing the internet without any problems. Explain how the operating system distributes the workload between the file copy and the browser, and describe what you notice if the USB flash drive is very slow.

The system asks for a password to install a new program, but not to open a text document. Reason why the operating system protects some actions and not others, and explain what could happen if installing programs did not require any permissions.

Two applications send documents to the printer almost at the same time. Explain what the operating system does so that the pages do not get mixed up (the 'print queue') and what happens if you cancel one of the two jobs.

Your phone displays the alert 'background applications have been closed' when you open many at once. Relate this alert to the RAM management carried out by the operating system and explain why the music app is usually the last one to be closed.

Compare the computer desktop with the physical desktop of your study table: what the folders, shortcuts and recycle bin represent, and who 'tidies the table' when you do not (think about automatic downloads or backups).

The same game exists for Windows, console and cell phone, but the file for one platform does not work on another. Using what you know about layers, explain why an application made for one operating system does not work on a different one and what developers must do to reach all platforms.

The classroom computer takes more than three minutes to respond after pressing the power button. When checking the list of programs that run automatically at startup, you find the following items:

1. Corporate antivirus (Impact: High)

2. Sound card driver (Impact: Medium)

3. Video game platform launcher (Impact: High)

4. Music player update assistant (Impact: Low)

1. a) Interpret this data: explain which computer resources (managed by the operating system) are being saturated during startup and why they slow down the machine even though you haven't opened any applications yet.
2. b) Decide, with justification, which programs you would disable from startup and which you would keep active to speed up boot time without compromising the security or basic operation of the computer.

Imagine you are designing the operating system for an ATM. Decide which applications you would allow to be installed, what its main screen would look like and what differences it would have compared to a cell phone system, prioritizing security and simplicity. Justify each decision.

A technology company wants to adapt the operating system of a desktop computer to install it on a low-cost sports smartband.

1. a) Select three typical functions of a PC operating system that you should eliminate or drastically simplify on the smartband, and justify each decision by relating it to a physical limitation of the device (battery, processor, or screen).
2. b) If a user demanded that the smartband allow having several floating windows at once and managing accounts for different family members as Windows does, what two technical arguments would you give to show them that this limitation is actually an advantage for the watch's operation?

A high school student downloads a game installer and another for a free 3D design program. When trying to run them from their student account, in both cases the operating system asks for the administrator password and blocks the installation. The student protests: «The operating system should allow installing the design software because it is educational and only block the games».

1. a) Technically refute the student's argument: explain why an operating system cannot distinguish by itself whether a file is 'educational' or 'entertainment' based on the permissions system.
2. b) Design a technical or configuration solution for the classroom that allows students to test necessary software tools for class without granting them full administrator permissions on the computers.

When a cell phone's operating system fails (the screen goes black, it restarts by itself), all applications stop working at once. Using the layer diagram, explain why a failure in that layer brings down everything else and what difference there is compared to a single application crashing.

To explain the role of the operating system, your working group proposes this analogy: «The operating system is like the control tower of a busy airport: the planes that want to land or take off are the applications, and the runways and boarding gates are the hardware».

1. a) Apply this simile to explain how the operating system resolves two real situations on a computer:

1. Two programs try to send a document to the single printer at the same time.

2. A program gets 'frozen' (crashes) and consumes all available memory.

1. b) Identify a fundamental aspect of the operating system (for example, the graphical user interface or file and folder management) where this control tower simile falls short or does not accurately represent reality, and explain why.

In a Technology class debate, two positions are raised:

• Position 1: «Any electronic device that has a microprocessor and executes instructions (such as a basic pocket calculator or a microwave) has an operating system».

• Position 2: «Those devices have a fixed program burned onto a chip, but lack an operating system».

1. a) Justify which of the two positions is technically correct, explaining what essential functions an operating system performs that do not exist in a simple household appliance.
2. b) If a traditional washing machine is upgraded with Wi-Fi connectivity and a touch screen to download wash programs from the internet and manage user profiles for the family, predict whether in that case integrating an operating system would be justified and explain your reasoning.