GB1482998A - Magnetic bubble domain chip - Google Patents

Abstract

1482998 Magnetic bubble devices INTERNATIONAL BUSINESS MACHINES CORP 5 Dec 1974 [28 Dec 1973] 52613/74 Heading H3B The propagation of a "scout" bubble through a magnetic bubble chip is monitored to determine the location of a fault and a magnetic switch is operated to cause subsequent bubbles to take a different path on the chip to bypass the fault. In the shift-register shown, a scout bubble generated at 14 is propagated through the first loop 1, the drive field reversed and the bubble magneto-resistively sensed at 44. The process is repeated through all the loops in series until the bubble is either not sensed at all or at the incorrect time, indicating that a fault exists in loop 3 (say). A bubble is then sent out to the beginning of the faulty loop and a conductor 22 pulsed to transfer the bubble to a permalloy retaining disc D3. Subsequent scout and data bubbles are repelled by the captured bubble and pass to the following loop via a Y-bar element 36-3. Continuously energized or synchronously pulsed switches may replace the permalloy discs. If a fault develops in use, the whole chip is saturated and the complete test programme repeated.