Marking of Assignment 9

Questions 1 and 2 were marked. Each question was marked out of 4 for a maximum of 8.

In Question 1 one mark was assigned for each of the following:

• correctly labeling the time axis (the labeling of the x-axis should allow the TA to determine the approximate bit duration).
• labeling the voltage axis (similarly, the labeling of the y-axis should allow the TA to determine whether the voltages are above or below the +/- 3 V thresholds).
• showing start and stop bits of the correct polarity
• showing the data bits with the correct polarity (L-H-L-H-L-H-L-H)

• stating that the first computer is a DCE
• stating that the second computer is a DCE
• stating that the problem is that both computers are wired as DCEs
• stating that a solution would be to use a null modem or for actually showing a diagram that crosses the signal lines (at least RxD and TxD)