X3?

i've seen a few instances of the arduino board, and most of them have four positions for pins labeled x3 next to the usb chip. what is the purpous of those pins?

i've seen them on NG's and diecemila versions

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1201053496

apparently they are not in use for the arduino.

this is the direct link

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1180915644/7