Complex sentence: It was acquired by HHB Systems, which in its turn was acquired by Daisy Systems in 1980s and in the early 1990s Simucad was spun off as a management buyout.
Split into simpler sentences: It was acquired by HHB Systems, which in its turn was acquired by Daisy Systems in 1980s. In early 1990s Simucad was spun off as a management buyout.