Circuit and module design for conductor-groove bubble memories

A read-write circuit for conductor-groove magnetic-bubble data storage loops has been tested which nucleates and destroys domains for writing and stretches domains along a thin Permalloy magnetoresistive element for detection. A small module the size of a 16-pin DIP package which can contain an 8 mm square garnet chip and bias magnet is described which could store 32-kbits if sixteen out of thirty-two 2-kbit storage loops on the chip are selectively connected. The organization of thirty-two such modules to make a megabit card is outlined. Circuit techniques are discussed which greatly reduce the effect of random propagation failures by rephasing the domain stream as it passes through the read/write area.