Magnetic bubble memory chip capacity has in creased rapidly and a 1 Mb chip is now available. As chip capacity increases, average access time increases, because bubble memory is originally a sequential access memory.
In order to improve the low access time, variouskinds of chip organization have been devised and developed, such as M/m loop organization, 2M line-m loop organization with block replicator and bidirec tionally propagating fast access chip.
A new chip organization, called on-chip-cache or ganization, was developed, which has 1/17 ti 1 /61 higher access time than that of a conventional organi zation. Chip design, data control method and organi zation effectiveness are shown, together with a new kind of housekeeper.
Finally, the organization trend for a large capacity chip, larger than 1 Mb, will be discussed.
