Abstract: A major/minor loop bubble memory system architecture includes a passive replicator in the major loop read channel which is connected by a first path to a mode switch-annihilator and a merge point in the major loop write channel and by a second path to an off-chip decision-making means and the merge point in the write channel. The decision-making means is positioned the same or fewer propagation steps than the mode switch-annihilator is from the replicator. The decision making means is activated to cause either the replicated data to pass through the mode switch-annihilator into the write channel or the replicated data to be annihilated in the mode switch-annihilator and the data from a generator to pass into the write channel.