On 26/08/2017 12:23, Peter Collinson wrote: I still have a copy of the V6 kernel which I ran on the University of Kent PDP-11/40 from about 1976. The files are dated Jan 13 1981 - but I think that was when I made off with the copy. The earliest date in the changes file is 1977. The system was hacked a lot - because in the days before the internet we were pretty much on our own - and actually we passed things around in the UK - but they didn't get much further. We picked up bits when we could and when they passed by. It has some interesting hardware drivers - an interface to the Cambridge ring for example - which UKC did in a big way before ethernet happened. I think that the tty.c driver came from Jim McKie that at Heriot Watt(?). I include a copy of conf.h where I documented the changes.