Complex sentence: Cray Research continued development along a separate line of computers, originally with lead designer Steve Chen and the Cray X-MP, and then, after Chen's departure, adding the Cray Y-MP and then Cray C90 and Cray T90.
Split into simpler sentences: Cray Research continued development along a separate line of computers. Originally with lead designer Steve Chen and the Cray X-MP, and then, after Chen's departure, adding the Cray Y-MP and then Cray C90 and Cray T90.