Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
12 Cards in this Set
- Front
- Back
|
What is an Operating System? |
There is no universally accepted definition. It can be described as a program that acts as an intermediary between a user and the computer hardware. It can manifest itself as a "resource locator", "control program", or all of the above. |
|
|
What type of program is loaded at power-up and where does it live? |
A bootstrap program, usually stored in ROM or EPROM (aka firmware) |
|
|
What is an interrupt vector? |
It is a table specifying the location of the interrupt handlers in memory. |
|
|
What does it mean when it is said that an Operating System is "interrupt driven"? |
It means that an OS must have a way of "interrupting" so it can gain control of the CPU when it wants. |
|
|
What are the two ways to check for interruptions? |
1) Polling - basically a busy loop 2) Vectored - only react when something has actually happened |
|
|
What is DMA? |
Direct Memory Access. It allows I/O devices to access memory directly without passing through (or interrupting) the CPU. DMA requires its own special simple CPU to perform the transfer. This performs much faster since only one short interrupt is generated per block, rather than per byte of data. |
|
|
What are the three tradeoffs when it comes to memory storage types? |
1) Speed 2) Volatility 3) Cost |
|
|
What is caching? |
Storing small amounts of important or frequently accessed memory typically stored in slow-access storage in faster-access storage. |
|
|
What are Interrupts, Exceptions and Traps and how are they related? |
Exceptions and Traps are types of Interrupts. Exceptions are thrown when errors occur, and traps happen when control is transferred to the OS. Interrupts include these and other things, for example a keyboard press. |
|
|
How many program counters does a multi-threaded process have? |
One program counter for each thread in the process (each thread can be at a separate location in the program) |
|
|
What does the I/O Subsystem do? |
1) Memory Management 2) General device-driver interface 3) Drivers for specific hardware devices |
|
|
What does Spooling mean? |
Spooling is an acronym for "Simultaneous Prehiperal Operations online". It's a type of buffering that lines up incoming jobs for execution |
