Participated in the ARPA-sponsored "summer
study group" that kicked off Project MAC at MIT. Wrote a
project memo about the dichotomy between "User System"
and "Service System." Essentials are described in Rpt-65C,
and the expanded dichotomy recurs as for instance in Pub-73-AKW
,Pub-78-IntEvolOAS and Pub-82-HiPerfKW. Had my turn to address
the whole group (50 or so people); not much reaction, but I do
remember the group hoot when I said that we'd all be seeking to
boost response time for many man-computer interactions down to
at least a quarter of a second before the returns began to diminish.