I don't think that terminal emulation is what you want. The good news is that minicom should do the trick.
The terminal emulation portion of minicom (or procomm or xtalk) simply allows you to make sense of what the other guy is transmitting (over a serial line).
Minicom can also be used for file transfers and that's what you want.
What you need to do is this:
1) Find out what the baud rate, word length (7 or 8), stop bit(s) parity, etc of the serial port is that you want to listen to.
2) Setup minicom to communicate using these parameters.
3) Make appropriate cable. (2-3, 3-2, 5-5, comes to mind).
4) Suck data.
And in case you are interested:
No mention of serial data...