to build the hardware, wire up leds with 330ohm resistors, anode to the data
lines, cathode to ground.

Usually, wire one led-resistor to each data line, pins 2-9.

data----|>|--/\/\---|
        LED 330ohm ---
                    -   ground

I'm not responsible if you fry the hell out of your machine.
Don't do this if you don't know what you're doing.  Contact me if you can't
build the hardware yourself.

spberry@iastate.edu  