I see in the downloads section for data files for the DACs on both of these boards some *.mat files and some *.txt files. I have tried loading both versions, and they both work. But, if I load the *.mat file into matlab, it looks like it consists of 2 columns of data. I assume these are the I and Q values at a given time sample point. Is this correct? How do you change the sample_frequency? And, where and what are the basic *.c codes that control the functionality in the SDcard for either unit that works with the ZC706? And, if I look at the *.txt files, they have TEXT as the first line, but then what looks like 4 columns. What are these 4 values? If there were 2 columns, I would assume I and Q, but what are the 4 columns? And, I assume the word TEXT in the first line is significant. Again, where and what are the *.c files that work with these data sets?