Charles "Charley" S. Kline is a computer scientist who studied at UCLA under Leonard Kleinrock (Professor of Computer Science). UCLA become the first node of ARPANET (forerunner of the Internet) and Kline played a role in installing an IMP (precursor to the modern day router) which enabled packet switching to function on ARPANET. Kline sent the first successful message on ARPANET: which was sent from ARPANET to SRI International: the message was the word "login". The system had previously crashed when the two nodes exchanged the letters "l" and "o" making "lo"; therefore "lo" is the first unsuccessful message sent on ARPANET, the first successful message is "login". The two computer located at UCLA and SRI International were made by Scientific Data Systems. They were not the same model of mainframe computer (Sigma 7 and 940); the Sigma 7 was the first 32-bit computer. Scientific Data Systems were purchased by Xerox in 1969. The message sent by Charley Kline was sent at 10:30pm on the 29th of October, 1969.