2.1 System software Flashcards
What is an operating system?
Essential for managing hardware and software resources of a computer system and provides an interface between user and hardware.
What are the main functions of an operating system?
Resource management, memory management, file management, interrupt handling, security, providing a platform for software to run, providing a user interface, and providing utilities.
What is resource management as a function of an OS?
OS manages computer resources, including CPU, memory, disk drives, and printers, allocating resources to specific tasks.
What is file management as a function of an OS?
OS handles storage, retrieval, and manipulation of data files, providing a GUI of the file system for user interaction.
How does an OS provide computer security?
Provides security features like password-protected accounts, firewalls, virus scanning, and file encryption.
How does an OS provide a platform for the computer to run on?
OS provides a platform for application software to run by allowing software to access system resources.
How does an OS provide a user interface?
OS provides interaction through a graphical user interface (GUI) or text-based command-line interface (CLI).
How does an OS provide utilities?
Utility programs help with system maintenance and security, such as file encryption, file compression, and disk cleanup.
What is file encryption?
A utility provided by OS that allows users to send files over networks securely.
What is file compression?
A utility provided by OS that reduces the size of the file, helping send large files over a network.
What is disk defragmentation?
A utility provided by OS that reorganizes files on the hard disk for faster access.
What is Disk Cleanup?
A utility provided by OS that scans the hard disk for duplicate and corrupt files and deletes them to create more space.
What is memory management?
A fundamental role of OS, dealing with allocation and deallocation of computer’s primary memory.
What are the benefits of memory management?
Efficient allocation of memory enables multitasking and maintains security by preventing programs from accessing reserved memory.
What techniques make memory management more efficient?
Paging, segmentation, and virtual memory.
What is Paging?
Method of chunking primary memory into equal-sized blocks for faster access, facilitating efficient memory management.
What is segmentation?
Divides memory into variable-sized segments based on logical parts of a process, allowing for intuitive memory access.
What is Virtual memory?
Using secondary storage as an extension of primary memory, allowing more extensive programs to run.
What is interrupt handling as a function of an OS?
An interrupt is a signal to the processor that stops its current task to perform a different task temporarily.
What is the purpose and role of interrupts?
Real-time event handling, device communication, and multitasking.
Describe the types of interrupts.
Hardware interrupts, software interrupts, and trap interrupts.
What is the interrupt process?
- Interrupt request 2. Interrupt acknowledge 3. Interrupt Service routine (ISR) lookup 4. ISR Execution 5. Interrupt exit.
What is an ISR?
A special function that handles a specific type of interrupt, designed to minimize execution time.
What is interrupt priority and nesting?
Interrupt prioritization allows resolving higher priority interrupts first, while nesting refers to handling interrupts within interrupts.
What is pre-emptive scheduling?
Allocates CPU for a specific time to a process, allowing interruption of currently handled processes.
What is non-pre-emptive scheduling?
Once CPU is allocated to a process, it holds it until completion.
What is Round Robin scheduling?
A pre-emptive scheduling algorithm where each job gets a time slice to run, moving to the back of the queue if not completed.
What are the benefits of Round Robin Scheduling?
All processes get a fair share of CPU, good for time-sharing systems, and predictable.
What are the drawbacks of Round Robin scheduling?
Choosing the right time slice size can be difficult, leading to high turnaround and waiting time for long processes.
What is First Come First Served scheduling?
A non-preemptive method where jobs are processed in the order they entered the queue.
What are the advantages of First Come First Served Scheduling?
Straightforward to implement and easy to understand.
What are the drawbacks of First Come First Served scheduling?
Can lead to poor performance if a long process arrives before shorter ones.
What is a Multi-Level Feedback queue?
A pre-emptive scheduling method prioritizing shorter and critical tasks using multiple queues.
What are the benefits of Multi-Level Feedback queues?
Takes into account different job priorities and prioritizes smaller tasks.
What are the drawbacks of Multi-level Feedback queues?
Difficult to implement and complex to set parameters.
What is Shortest job first scheduling?
A non-preemptive method where jobs are ordered by the time required for completion.
What are the advantages of Shortest Job first scheduling?
Reduces waiting time and is efficient for short processes.
What are the drawbacks of Shortest Job first Scheduling?
Requires knowing job durations in advance and can lead to processor starvation.
What is processor starvation?
When a process does not receive enough CPU time to execute and complete.
What is shortest remaining time scheduling?
A pre-emptive method prioritizing processes with the shortest remaining time.
What are the advantages of Shortest Remaining time scheduling?
Increases throughput by quickly completing shorter processes.
What are the drawbacks of Shortest Remaining time scheduling?
Requires advance knowledge of burst times and can lead to processor starvation.
What are the types of operating systems?
Distributed, embedded, multi-tasking, multi-user, and real-time.
What is a Distributed OS?
Runs on multiple machines appearing as a single unit for efficient task distribution.
What is an Embedded OS?
Designed for specific tasks in devices, limited in functionality but uses less power.
What is a Multi-Tasking OS?
Allows multiple tasks to run concurrently on a single processor using time slicing.
What is a multi-user OS?
Supports multiple users accessing resources concurrently while managing security.
What is a real-time OS?
Designed for immediate data processing and ensures tasks are processed within specific timeframes.
What is the BIOS?
Basic Input/Output System, the first software to run on system start, performing POST.
What is a POST?
Power On Self Test, a diagnostic sequence ensuring hardware components are working properly.
What is a device driver?
Software that enables communication between an OS and hardware like printers and graphics cards.
What are Virtual Machines?
An entire OS run inside another OS, providing an environment for software designed for specific OS.
What is intermediate code?
Code that is halfway between machine code and object code, independent of processor architecture.
What are uses of Virtual Machines?
Testing programs on different OSs, protection from malware, and running incompatible software.
What are the drawbacks of using Virtual Machines?
Overuse can exhaust host OS resources, and activation payments may be required for full features.
