Err, NCP, not the ARPANet. The latter kept running for quite some time, serving as the Internet's wide-area backbone, and was only slowly turned off (IMP by IMP) in the late 80's, with the very last remnants finally being turned off in 1990. A few, yes, but NCP was indeed turned off for most hosts on January 1, 1983. Huh? As I just pointed out, TCP/IP (and the Internet) was a going concern well _before_ January 1, 1983 - and one can confidently say that even had NCP _not_ been turned off, history would have proceeded much as it actually did, since all the machines not on the ARPANET would have wanted to be connected to the Internet. (Also, to be technical, I'm not sure if TCP/IP ever really ran on CHAOSNet hardware - I know I did a spec for it, and the C Gateway implemented it, and there was a Unix machine at EECS that tried to use it, but it was not a great success. Workstations connected to the CHAOSNet as of that date - AFAIK, just LISP Machines - could only get access to the Internet via service gateways, since at that point they all only implemented the CHAOS protocols; Symbolics did TCP/IP somewhat later, IIRC, although I don't know the exact date.) Noel