The AI lab PDP-6 arrived in 1964. It never had a name per se. It was first used standalone, but a need for timesharing resulted in ITS running in July 1967.
Next came the AI lab PDP-10 with a KA10 processor. It was named AI when ITS moved to more machines.
The Dynamic Modeling group received a pre-owned PDP-6 in 1969. It was never used much.
The DM KA10 arrived in 1970.
The Mathlab KA10 was delivered in 1971 and became operational during 1972. It was named ML.
The Macsyma Consortium KL10 arrived in 1975 and was named MC.
In the late 1970s, the two PDP-6 machines fell into disrepair.
In the early 1980s, the three KA10 machines were shut down.
Four new KS10 machines were donated by DEC in the mid 1980s and ITS was ported. They took the names AI, ML, MD, and MX.
MX and MC swapped names, and the KL10 was shipped to Sweden in 1988.
The last KS10 machines were shut down in 1990, with AI briefly making a reappearence in 1991 to send a farewell message to SAIL.