Why is fragmentation a serious concern for multiprogramming with variable partitions but it is not an issue for multiprogramming with virtual memory?

In a virtual memory approach, a program needs a new page, but there are no available frames. What happens?

In a fixed partition approach, a 12 KiB program is ready to be loaded, but the only available partitions are 4 KiB and 8 KiB. What happens?

In a variable partition approach, a 12 KiB program is ready to be loaded, but the only available partitions 4 KiB, 6 KiB and 8 KiB. What happens?

Assume the following diagram represents a virtual memory approach to main storage allocation. Also assume that job J3 needs page 3 to be loaded and executed. How would you modify the picture to accommodate the new page.

Part IV: Error Detection and Correction (12 points):

Using the following string, determine if there is a single error or no error. If there is a single error, identify the bit that needs to be corrected. The string consists of 8 data bits and 4 parity bits. The parity bits are set at the positions representing the binary powers of 2. The code uses odd parity. (10 points)

Parity bit 1 checks 1, 3, 5, 7, 9, 11

Parity bit 2 checks 2, 3, 6, 7, 10, 11

Parity bit 4 checks 4, 5, 6, 7, 12

Parity bit 8 checks 8, 9, 10, 11, 12

Input String: 101101001011

As you can see from above, a Hamming Code works as follows:

Bit position 1 checks every other bit, starting from itself.

Bit position 2 checks 2 bits, skips 2 bits, checks 2 bits, skips 2 bits, starting from itself.

Bit position 4 checks 4 bits, skips 4 bits, checks 4 bits, skips 4 bits, starting from itself.

Bit position 8 checks 8 bits, skips 8 bits, checks 8 bits, skips 8 bits, starting from itself.

Assuming I have 26 data bits, how many parity bits should I have and where should they be placed in the string? (2 points)

Part V: Various Short Answers (14 points)

What is the difference between an assembly language designation of DC and DS?

What are the components which make up access time for a hard disk drive and what does each component mean?

What are a half-adder and full-adder?

Describe how page swapping works.

How does a program achieve mutual exclusion using 3 sections of code?

Draw a circuit which achieves the following: ((a + b) . (b + c)) . (b + c).

In the circuit from #6, what are the results if a = 0, b = 0, c = 1?

Part VI: Basic Assembly Language Concepts (22 points)

For each defined constant below, specify the hexadecimal configuration: (3 points each)

TESTVAL1 DC H91

TESTVAL2 DC F-52

TESTVAL3 DC PL524579

TESTVAL4 DC CL5ABD (EBCDIC coding Note: A = C1, B= C2, D = C3, space = 40)

2.The following instructions are a subset of an assembly language program: (2 points each)

BALR R8,0 appears at hexadecimal address 000A

The next line says USING *,R8

The next line says LH R4,TEMP1

TEMP1 DC H15 appears at hexadecimal address 016C

How is the address of TEMP1 calculated and what values are used?

Assume at execution time that the first instruction of the program is loaded at hexadecimal memory address 156000. How does that affect the addresses calculated at assembly time?

What is the purpose of the USING instruction?

What is meant by the terms logical addressing and physical addressing?

In order for the assembler to recognize the BALR instruction, what assembler directive is necessary?

Part VII: File Management Concepts (12 points)

What are the two purposes served by implementing RAID technology? (2 points each)

Define the following terms: (2 points each)

Block

Stripe

Mirror

Look-ahead Buffering

If I only do mirroring, what benefit is served? (2 points)

Analyze the following resource allocation graph. Explain whether a deadlock will occur and the order in which the programs will be able to execute:

0 0