@icm In 1994, there were still a couple of 3650s on the 5th floor as well, used by PIs in the Advanced Network Architecture group (for whom I worked at the time). I'm not sure when those left, but they were certainly gone by 1997 when I took a different job and was rebuilding the network in NE43. There were a lot more Lispms still in use in the AI Lab but I never saw them until ca. 2000 when we started planning for the new building.