Browse Prior Art Database

Random Read Shift Register Bubble Memory

IP.com Disclosure Number: IPCOM000078085D
Original Publication Date: 1972-Nov-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Levi, R: AUTHOR

Abstract

This shift register memory permits random access.

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Random Read Shift Register Bubble Memory

This shift register memory permits random access.

The illustration shows six positions 1 to 6 of a random-access memory, in which the second position 2 is being accessed. To accomplish accessing, sense line 2 is first raised to a high potential. Then current I1 is injected through bit line 2, causing the bubbles along bit line 2 to move from position A to position
B. Thereafter, bit line 2 is grounded and current I2 is passed through the word line 1, simultaneously with the passage of a sense current through sense line 2. This causes all bubbles along word line 1 to move from position A to position D, except for the bubble in bit 2 which will move from position B to position C. While the bubble in bit 2 moves from position B to position C, it crosses a sensor and produces a variation in sense current on sense line 2. After the sensing is completed, a current I3 is passed through bit line 2 while maintaining sense line 2 at a high potential, moving all bit line bubbles to their original position A, except in the second bit 2 which moves from position C to position D. Current I4 is then passed through word line 1 to return all bubbles to their original position A.

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