I do it with a null modem cable, an FTDI (USB-to-RS-232C) cable, and PuTTY for ASCII (.DO) transfers. The basic operation is as described here:
http://club100.org/library/twe/c2c02.html but the mechanics are a little different (and perhaps easier) with PuTTY. At step 5, you simply copy the contents of the .DO file to your clipboard, then right-click in the PuTTY window. That pastes the text into the application on the other end of the connection -- the M100's TEXT program in this case.
