Q & A on Serial Data Transmission Q: I am having difficutly understanding and answering these questions. I was wondering if you could help me? I am a IT major at MBCC a community college in MA. Thank you, A dedicated student A: Instructors have asked me not to answer questions outright (for the obvious reason). However, I'll give you some hints. Q: 4.3) Suppose one sent 1000 7-bit characters across an RS-232 connection that operated at 9600 baud. How long would the transmission require? (hint: remember to allow for a start bit and a stop bit on each character.) A: If you know (a) the total bits sent, and (b) the number of bits per second, you can compute the time requried. So, all you need to do is figure out the number of bits sent for 1000 7-bit characters with one stop bit and one start bit per character. Easy, isn't it? Q: 4.10) Most RS-232 hardware allows the computer to which it attaches to specify the data rate to use as well as the number of stop bits to use. If a transmitter is programmed to use two stop bits, but a receiver is programmed to require only one, will data be received correctly? If so, what is the disadvantage of using an extra stop bit? A: If you understand why RS-232 is ``asynchronous,'' you should be able to answer first question. To answer the second part, think about applying the same analysis as in problem 4.3.