Developed for IBM 360/91 in 1967 (about 3 years after CDC 6600)
Hazard detection and execution control are distributed among the functional units (vs. centralized in scoreboard)
Reservation stations at each functional unit control when an instruction can begin execution at that unit.
Common Data Bus broadcasts results to all reservation stations (of all FUs)
Load and Stores treated as FUs as well.
Each Register has additional flags.