Yes. See: http://ana-3.lcs.mit.edu/~jnc/history/RingMIT.txt for more - that's a pre-print version of an article just published in the _IEEE Annals of the History of Computing_; slight differences with the final version, but nothing significant. Thumbnail: There were two versions; V1 was 1MBit/second, produced in very limited numbers (~10 or so) at MIT, most used there, although IIRC correctly at pair (at least - one would be of no use :-) went to UCLA (I remember flying out to LA to help them get them going). V2 was 10Mbit/second, produced as a commercial product by Proteon in cooperation with MIT, large numbers sold. Noel