Processing of inverted files in magnetic-bubble memories

In this paper the applicability of magnetic-bubble memories to the processing of inverted files is discussed. Four novel models of magnetic-bubble memories are presented to demonstrate storage structures and data processing. The first model employs an organisation of major/minor loops. On the basis of such an organisation a uniform ladder is formed so that the data can be rearranged by using four operations: global shift, detached shift, exchange and delta exchange. The second model makes use of the on-chip decoder (also known as the self-contained magnetic-bubble-memory chip). For this model a hashing scheme is relied upon to perform the required data operations. The third and fourth models are different combinations of the former two models. The latter two models provide a relatively-high-speed performance as well as a reasonable system complexity. For each model the algorithms of data retrieval, sorting, deletion, insertion and updating are given. A comparison of the four models has been carried out in order to determine the most convenient magnetic-bubble-memory structure for the processing of inverted files.