Posted: September 16th, 2017
Computer and Number Systems
1. (10 pt) Create a list of at least four of the important protocols that are members of the TCP/IP protocol suite (OTHER THAN TCP and IP) and the layer in which they operate. Explain how each protocol contributes to the operation and use of the Internet.
2. (2.5 pt each) In order to receive credit for these problems, you must show all of the steps you took to arrive at your answers.
(c) Convert the following decimal number to binary:
31654
31654
(d) Convert the following binary number to decimal:
10111010011.011
10111010011.011
(c)Convert the following hexadecimal number to decimal:
CD63
CD63
(d) Convert the following binary number to hexadecimal:
1101001111001011011
1101001111001011011
CPU and Memory
3. (10 pt) ASCII, Unicode, and EBCDIC are, of course, not the only numeric / character codes. The Sophomites from the planet Collegium use the rather strange code shown in the Figure below. There are only thirteen characters in the Sophomite alphabet, and each character uses a 5-bit code. In addition, there are four numeric digits, since the Sophomites use base 4 for their arithmetic. Given the following Sophomitesequence, what is the corresponding binary message being sent by the Sophomites?
(HINT: Decode the sequence reading from left to right then write the corresponding binary sequence, leaving a space between each binary sequence.)
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Character Codes
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Numeric Codes
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00001
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10000
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11111000
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00010
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10011
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11111011
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00100
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10101
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11111101
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01000
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10110
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11111110
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01011
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11001
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01101
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11010
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01110
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Input / Output
5. (10 pt) Consider the interface between a computer and a printer. For a typical printout it is clearly impractical to send output data to the printer one byte or one word at a time (especially over a network!). Instead, data to be printed is stored in a buffer at a known location in memory and transferred in blocks to memory in the printer. A controller in the printer then handles the actual printing from the printer’s memory.
The printer’s memory is not always sufficient to hold the entire printout data at one time. Printer problems, such as an ‘‘out of paper’’ condition, can also cause delays. Devise and describe, in as much detail as you can, an interrupt/DMA scheme that will assure that all documents will be successfully printed.
6. (10 pt)Discuss the major differences, similarities, advantages, and disadvantages between bus I/O and channel I/O.
Networks
7. (10 pt) Discuss the trade-offs between bus-based and switched Ethernet. State the various conditions under which one or the other would be preferred and explain why.
8. (10 pt) There are four different ‘‘addresses’’ that are normally used during the passage of a message from source to destination using TCP/IP and Ethernet. These include a ‘‘user-friendly’’ address, a port number, an IP address, and a physical address. For each ‘‘address’’ state which layer or pair of layers uses that address and explain carefully how the address is used.
Data Communications
9.(2 pt each)Circle or highlight the correct answer to the following questions / statements about data communications:
(a)What modulation type encodes data by varying the magnitude of wave peaks within a carrier wave?
a. phase c. frequency
b. packet d. amplitude
(b)What term corresponds to the following definition: noise added to the signal in the wire from EMI generated by adjacent wires?
a. skew c. both a and b
b. crosstalk d. neither a nor b
(c)Fiber optic cable segments can be longer than copper cable segments because optical signals experience less ____.
a. signal/noise (S/N) ratio c. attenuation
b. compensating errors d. multipath distortion
(d)A(n) ____creates a new virtual LAN for each packet and destroys the virtual LAN as soon as the packet has reached its destination.
a. bridge c. router
b. hub d. switch
(e)When multiple nodes attempt to transmit across the same medium at the same time a(n) ____ is said to have occurred
a. connection c. load imbalance
b. collision d. transparent access
Operating Systems
10. (10 pt) What operating system functions would you expect to find in the computer that is built in to control your automobile, and which functions would be omitted? Provide at least two of each. Justify your answer.
File Management
11. Answer the following:
a.(5 pt) Use the following four processes that have arrived in the ready queue in the sequence shown below and answer the following about process scheduling:
- Process 1 has a total run time of 20 seconds and a priority of 2, but it will require 15 seconds of I/O after 10 seconds of execution
- Process 2 has a total run time of 25 seconds, a priority of 1, but it will require 10 seconds of I/O after 20 seconds of execution
- Process 3 has a total run time of 5 seconds and a priority of 3
- Process 4 has a total run time of 30 seconds, a priority of 1, but it will require 20 seconds of I/O after 10 seconds of execution
(i)Both shortest job first and non-preemptive priority queue scheduling algorithms will complete all four processes at the same time, but not in the same order. In which algorithm will Process 1 finish first? Provide the time Process 1 finishes for each algorithm and explain your answer.
(ii)If the round robin with priority queues scheduling algorithm is used, which process will finish second? At what time will it complete?
b.(5 pt) Using a variable-partitioned multiprogramming memory, which of the four holes shown below will be used to satisfy a 35 KB program requirement under the conditions of:
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0-15 KB
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15-40 KB
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40-125 KB
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125-155 KB
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155-275 KB
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275-315 KB
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315-420 KB
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420-465 KB
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465-505 KB
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occupied
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Hole A
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occupied
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Hole B
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occupied
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Hole C
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occupied
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Hole D
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occupied
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___ Best-fit
___ Worst-fit
Internet
12. (10 pt)Show the bit pattern in an asynchronous transmission with evenparityif the data to be sent is “EXAMS” by filling out the table below. Use 7-bit ASCII code found in Englander’s Figure 4.3 (page 102) and be sure to include start and stop bits.
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Example
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Start
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m
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Parity
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Stop
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0
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1001101
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0
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1
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7 bit-ASCII
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Start
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E
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Parity
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Stop
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Start
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X
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Parity
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Stop
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Start
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A
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Parity
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Stop
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Start
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M
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Parity
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Stop
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Start
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S
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Parity
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Stop
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