Assignment 1

1061 Words Sep 22nd, 2015 5 Pages
Fundamentals of Information Technology

1). How does an operating system ensure that hardware is used efficiently? Operating system can ensure processor to be used efficiently by the multiprogramming feature. Since the processor is fast while I/Os are slow, operating system needs to prevent processor from wasting time doing nothing and just waiting for I/O to complete. By having more than one program in memory, operating system will be able to let processor work on another program while the first program is waiting for I/O to complete. Once the first program’s I/O is done, operating system will let processor to resume the first program. In this way, processor can be kept busy working on different programs while certain I/Os are taking
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Briefly describe each type of event and explain why each is needed. (Please use a separate paragraph for each type of event.) One type of event is called exception. Basically exceptions refer to, while executing a program, something unexpected (like an error, in my understanding) happened. Therefore an exception is needed here to change the flow of control. Exception can also happen if operating system must take over control and operate some other operations. This is called “system call”. Both the two situations can cause an exception to happen and call attention to handle the exception first. If the exception is solved, it can return to the program. Otherwise, the program will be aborted. The other type of event is called hardware interrupts. Hardware interrupts refer to, while executing a program, something external happened and needs attention. One of the examples is when a printer runs out of paper. Hardware interrupts can enable efficient use of processor, because it allows process to work on other instructions while waiting for I/O to respond. When I/O completes, a hardware interrupt will occur and inform the processor to stop and come back. 4). Over the past decade, processor manufacturers, like Intel, have used various technologies to increase system performance. Describe in detail 3 of these technologies as discussed in the online content. (Please use a separate paragraph for each technology.)
The following…

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