1. A 32-bit computer has two selector channels and one multiplexor channel. Each selector channel supports two hard disks and two DVDs units. The multiplexor channel has two printers connected to it. Assume the following transfer rates.

Disk drive 900 Kbytes/s

DVD drive 800 Kbytes

Printer 100 Kbytes/s

Estimate the maximum aggregate I/O transfer rate in this system.

Show how you estimate.

2. Given the following set of events, show which routines the CPU is executing for times 0 to 150 ms. Each handler routine (with its interrupt request) takes 25 ms to complete. The priority of the interrupts ranges from IRQ6 as the highest priority interrupt to IRQ0 as the lowest priority interrupt.

Time	Action
0 ms	Start of main program
10 ms	IRQ1
25 ms	IRQ2
35 ms	IRQ5
45 ms	IRQ6
55 ms	IRQ4

Time Action

0 ms: Start of Main Program

10 ms: IRQ1

.. ms .

3. Why do you think the term random access device is something of a misnomer for disk drives?

4. What are the advantages and disadvantages of having a small number of sectors per disk cluster?