After a brief survey of the basic Atlas machine, the paper describes an automatic system which in principle can be applied to any combination of two storage systems so that the combination can be regarded by the machine user as a single level. The actual system described relates to a fast core store-drum combination. The effect of the system on instruction times is illustrated, and the tape transfer system is also introduced since it fits basically in through the same hardware. The scheme incorporates a ``learning'' program, a technique which can be of greater importance in future computers.