Complex sentence: In the 1960's, SDC developed the AN/FSQ-32 mainframe computer system for ARPA, which one of the first systems to support both timesharing and inter-computer communications.
Split into simpler sentences: In the 1960's, SDC developed the timesharing system for the AN/FSQ-32 mainframe computer for ARPA. The Q-32 was one of the first systems to support both multiple users and inter-computer communications.