No, AT&T did patent much of their inventions, they were prohibited from doing something other than phone service and related equipment, so they licensed or gave

No, AT&T did patent much of their inventions, they were prohibited from doing something other than phone service and related equipment, so they licensed or gave away their IP. They also had broad cross-licensing agreements with their competitors in the industry (ITT/Kellog and Automatic Electric). AT&T however was prohibited from selling computers until the 1956 consent decree was vacated in 1984.