Magnetic Bubble Memory Organization

Magnetic bubbles offer promise of data storage at a lower cost than is possible using semiconductor technologies. However, a memory using magnetic bubbles is most economically implemented in the form of long shift registers, rather than as a random access storage device. This plus a lower shift rate than is possible with semiconductors suggests relatively long average access times. This shortcoming is largely overcome by an organizational technique called dynamic ordering, which can reduce the average number of shifts needed to access data. A dynamically ordered magnetic bubble memory, when combined with one or more smaller semiconductor memories in a hierarchy, should provide both large capacity and good performance with reasonable economy.