Complex sentence: It was the first company to produce an off-the-shelf theatre sound design console (Model 816) in 1973 and the first off-the-shelf computerized modular theatre sound design control system (Command/Cue) in 1985.
Split into simpler sentences: It was the first company to produce an off-the-shelf theatre sound design console (Model 816) in 1973. RSD produced the first off-the-shelf computerized modular theatre sound design control system (Command/Cue) in 1985.