Wow, I've got some reading to do. Thanks.
Actually, i have two problems. Yes, I do need to get from binary to decimal ultimately. But what I can capture in Hyperterminal (with my limited skills) is strings of funny characters (little smileys etc.) I presume this is because the binary is being represented in the captured txt file as ascii characters, not strings of 1's and 0's. So, I need to get the true binary, then turn it into decimal in an ASCII text file that I can open in Excel.

I'll try to get me some education on this now. Thanks everyone for the links and advice.