QUESTION TWO [20 Marks] A) From the point of view of the device driver, data may be read from an I/O device
using polling, Interrupt-driven programmed I/O, or Direct Memory Access(DMA).
Required:- Explain each of above terms, and in each case outline using pseudo-code
(or a flow chart) the flow of control in the device driver when reading data from
the device.
[14 Marks]
B) Give an example situation in which operating systems effectively consider disk storage to
be a fourth type of memory".
[2 Marks]
C) Explain the operation of a multi-level feedback queue in process scheduling. [4 Marks]