The benefit of a DMA channel is that it proceeds with an I/O task independently of, and in parallel
with, the CPU. For full efficiency, the CPU should not have to stop and poll the DMA channel
periodically for its state; the CPU should be allowed to continue its other work until the DMA
channel accomplishes the entire transfer and signals the CPU with an interrupt.
6.3 What scheduling concept was critical to the development of timesharing computers, and has remained an
important part of scheduling for interactive computer systems?
The round robin scheduler was the basis of the first timesharing computers. Each user in turn
received his ???time slice.??? The effect was to make each user feel he was the sole user of the machine.
Variations on round robin scheduling continue to be important mechanisms for providing interactive
computing on multiuser computers.
6.4 Categorize the following programs as system software or application software, and explain your
categorization:
Java Virtual Machine
system software??”facilitates program development and execution
Excel
application software??”used specifically for spreadsheet applications
Powerpoint
application software??”used specifically for creating presentations
C compiler
system software??”facilitates program development and execution
C library
system software??”facilitates program development and execution
Oracle database management system
difficult to say, but I would choose system software.
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