Complex sentence: Johnson joined AMD in 1985 as the chief architect of the AMD Am29000 family (commonly known as "29K") of microprocessors, and held various management and leadership positions on the 29K, K5 and K7 processor teams.
Split into simpler sentences: Johnson joined AMD in 1985 as the chief architect of the AMD Am29000 family (commonly known as "29K") of microprocessors. He held various management and leadership positions on the 29K, K5 and K7 processor teams.