The first message on the ARPANET was sent by UCLA student programmer Charley Kline, at 10:30 pm on 29 October 1969, from Boelter Hall 3420.[16] Kline transmitted from the university’s SDS Sigma 7 Host computer to the Stanford Research Institute’s SDS 940 Host computer. The message text was the word login; the l and the o letters were transmitted, but the system then crashed. Hence, the literal first message over the ARPANET was lo. About an hour later, having recovered from the crash, the SDS Sigma 7 computer effected a full login.     http://en.wikipedia.org/wiki/ARPANET