Question 4 (25 marks) a) Briefly describe any 3 characteristics of I/O devices. (6 marks) b) For handling an I/O operation, there are two possible approaches: synchronous I/O and asynchronous I/O. State the difference between these two approaches. (2 marks) c) What is the major difference between programmed I/O, and interrupted I/O with the DMA? (2 marks) d) The PIO involves two things the I/O command that is provided by the processor to the I/O module and the I/O instruction that is encountered and executed by the processor. What types of I/O commands would you consider needed to be included? Explain. (4 marks) e) Describe the advantages of using DMA and its drawbacks. (4 marks) f) DMA can be operated in burst mode and cycle stealing mode. Briefly describe how they work. (4 marks) g) What is Firewire? Firewire is hot-swappable, what does it mean