Questions:

Q-1. On a system with 2²⁴ bytes of memory and fixed partitions, all of size 65,536 bytes, what is the minimum number of bits needed in an entry in the process table to record the partition to which a process has been allocated?

Solution:

Q-2. On a system using fixed partitions with sizes 2¹⁶, 2²⁴ and 2³², how many bits must the limit register have?

Solution:

Q-3. On a simple paged system, the TLB holds the most active pages and full page table is stored in the main memory. If references fulfilled by the TLB take 100 ns, and references through the main memory page table take 180 ns, what must the hit ratio be to achieve an effective access time of 125 ns?

Solution:

Q-4. On a system using simple segmentation, compute the physical address for each of the logical addresses, given the following segment table. If the address generates a segment fault, indicate this as well.

Segment	Base	Length
0	330	124
1	876	211
2	111	99
3	498	302

(a). 0, 99 [Segment#, Offset]

Ans =

(b). 2, 78

Ans =

(c). 1, 265

Ans =

(d). 3, 222

Ans =

(e). 0, 111

Ans =

Q-5. Given a system with four page frames, the following table indicates page, load time, last reference time, dirty bit, and the reference bit.

Page#	Load Time	Last Reference	Dirty Bit	Reference Bit
0	167	374	1	1
1	321	321	0	0
2	254	306	1	0
3	154	331	0	1

(a). Which page will FIFO replace?

(b). Which page will LRU replace?

(c). Which page will NUR replace?