Using the SimpleMessageSystem you can interface the Arduino to a HyperTerminal session.
1) Open HyperTerminal (sorry, but my version of Windows is in French, I will try to translate the window contents as I go on).
2) Create a connection called "arduino".
3) Select the proper port (the Arduino is set to COM4 on my machine). Don't change the rest of the fields, they don't matter.
4) Configure the port: Set the baud rate to 9600, the bits to 8, parity to none, stop bits to 1, and flow control to none.
5) You are done. If your Arduino is programmed with the example code distributed with the SimpleMessageSystem library you can type these messages (be warned that while you are typing, nothing will appear on the screen, that is normal. Only stuff that the Arduino sends back will be printed on screen):
w d 13 1
Do not forget the spaces and always finish a message by hitting return on your keyboard (that actually sends the carriage return character). The first message will turn on an LED connected to port 13. The second message will return the value of all the analog inputs. The third message will return the value of all the digital inputs.
Questions or comments: tof [at] danslchamp.org