Bubble memory with conductor programmable transparent error map

Abstract

Disclosed is a bubble memory having a plurality of data loops, some of which may be defective, and first input and output paths for propagating magnetic bubbles to and from the data loops, respectively. The memory further includes a plurality of redundant loops, and second input and output paths for propagating magnetic bubbles to and from the redundant loops, respectively. A pair of bubble generators are provided for simultaneously generating the same input data stream on both the first and second input paths. By selectively disabling certain first transfer gates associated with the data loops magnetic bubbles are prevented from being transferred into defective ones of the data loops. By selectively enabling certain second transfer gates and certain second replicate gates, magnetic bubbles representing the same information as those not transferred into the data loops can be stored and retrieved from the redundant loops. Magnetic bubbles replicated from the redundant loops are merged into corresponding vacant positions in the output data stream propagated from the data loops before the stream reaches a bubble detector. The gates are selectively disabled or enabled by opening one of two parallel connected conductor segments in each of the gates.