Chapter 1: Introduction Flashcards
What is an Operating System (OS)?
What are its goals?
A program that manages the computer hardware.
It also provides a basis for application programs and acts as an intermediary between the computer user and the computer hardware.
Execute user programs and make solving user problems easier
Make the computer system convenient to use
Use the computer hardware in an efficient manner
Four rough components of an OS?
- Hardware
- The OS
- Application Programs
- The Users
What is hardware and what does it do?
Physical components of a computer such as the Central Processing Unit (CPU), the memory, and the Input/Output (I/O) devices.
They provide the basic computing resources for the system.
What are examples of Application Programs and what are they used for in general?
Word processors, Spreadsheets, Compilers and Web. They define the ways in which these resources are used to solve users’ computing problems.
What’s a Kernel?
The one program running at all times on the computer.
What’s the Bootstrap Program?
Where is it stored?
The program started a powerup. Loads Kernel and starts execution. Typically, it is stored in read-only memory (ROM) or electrically erasable programmable read-only memory (EEPROM), known by the general term firmware.
What’s an interrupt? What does it do?
Name 2 ways to receive an interrupt.
Signals the occurrence of an event.
Hardware may trigger an interrupt at any time
by sending a signal to the CPU, usually by way of the system bus. Software may trigger an interrupt by executing a special operation called a system call (also called a monitor call).
What’s a trap or eception?
Software generated interrupt caused by an error or user request.
What’s caching?
copying information into faster storage system; main memory can be viewed as a cache for secondary storage
What’s a device driver?
Provides a uniform interface between controller and kernel.
Name 3 advantages of Multiprocessors and 2 types of Multiprocessors.
Advantages:
- Increased throughput
- Economy of scale
- Increased reliability - graceful degradation or fault tolerance
2 types are asymmetric and symmetric multiprocessing
What are Clustered Systems? What do they do?
Multiple systems working together. Share storage through storage-area network (SAN).
Provides a high-availability service which survives failures
What is Multiprogramming?
Multiprogramming increases CPU utilization by organizing jobs (code and data) so that the CPU always has one to execute.
What is Timesharing/Multitasking?
is logical extension in which CPU switches jobs so frequently that users can interact with each job while it is running, creating interactive computing
What’s Dual-Mode?
Allows OS to protect itself and other system components.
User mode and kernel mode used and distinguished by mode bit.
