Browse Prior Art Database

Managing Dummy Bubbles in Bubble Lattice File Storage Systems

IP.com Disclosure Number: IPCOM000087180D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 41K

Publishing Venue

IBM

Related People

Kinberg, C: AUTHOR

Abstract

Dummy bubbles within a bubble lattice structure operate to move data bubbles between lattice storage areas and input/output ports to the lattice. Dummy bubbles also serve as "gaps" separating sequences of data bubbles. Data bubbles are bubbles exhibiting domain wall magnetic orientations corresponding to arbitrary "data values."

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 3

Managing Dummy Bubbles in Bubble Lattice File Storage Systems

Dummy bubbles within a bubble lattice structure operate to move data bubbles between lattice storage areas and input/output ports to the lattice. Dummy bubbles also serve as "gaps" separating sequences of data bubbles. Data bubbles are bubbles exhibiting domain wall magnetic orientations corresponding to arbitrary "data values."

With reference to Fig. 1, it should be noted that because of the extremely small distances between the individual bubbles, which are in the order of 1-2 mu meters, the bubble generators and the sensors, which themselves require an order of magnitude (at least) more space than an individual bubble, cannot produce or evaluate a bubble right at the edge of the matrix. Thus, a bubble has to be produced at some distance from the matrix and stepped up to the entry point. Similarly, there is some distance between the matrix and the sensing station which the bubbles have to travel before their information contents can be evaluated. This travel to and from the matrix, within which all stored data has to reside, requires the use of dummy bubbles to "push" a record onto the matrix or off the matrix to the read station. Consequently, each time a new record is to be recorded (stored), it will be preceded by a set of dummy bubbles left in the path between the generator and the matrix. If several records are being written, no dummy bubbles would have to be inserted between the records. However, to avoid losing data in the path between the matrix and the reading station, it may be necessary to insert dummy bubbles between the records to permit the reading of one record without having the subsequent record leave the matrix.

A new problem is faced when it is desired to store a record by inserting it between already existing records. Since now a reordering of records must be accomplished, means for moving parts of the data in a cell, while leaving other parts stationary, must be provided.

Fig. 2 shows how insertion of a record can be accomplished by an auxiliary plane with a separate Y-server, and Fig. 3 depicts the communication path between the planes. With reference to Figs. 2 and 3, the execution of an insert will be shown. A record is to be inserted (in key sequence) at point IP in the T- cell of Fig. 2. Step one consists of transferring all data in front of IP to the auxiliary plane (with switch St set in the "a" position, Fig. 3). In step two, the new record is written in the auxiliary plane via the Wa terminal (with switch St in the "t" position). In step three, the data beyond IP is transferred to the auxiliary plane (with switch St in the "a" position). Finally, in step four, the data is transferred back to the T-cell (with the switch Sa in the "t" position).

To minimize the amount of storage lost to dummy bubbles, a certain level of blocking of records may be called for, especially if the records are very short. This implies that an entire block would h...