Most data processing systems require mass memory storage facilities that store large amounts of data. One such mass memory device is a hard file or hard file. The hard file includes several surfaces having a magnetic coding for the magnetic storage of data. Data is stored and retrieved by moving a magnetic sensor or head over the surface. The surfaces are rotated at a high speed. Data is stored on the surfaces, in concentric channels termed tracks. Each track includes a series of sequentially located sectors that are addressable for the storage and retrieval of data. A head located above a track does not have to be moved to read or write data in sectors of that track since the rotation of the surface will eventually bring the sectors of this track into proximity with the head. When information is located on a different track, the head will have to be relocated over that track to read or write data into sectors of that track. The movement of this head is termed a seek operation.
Small data buffers have been used to interface to the hard file mass memory devices. The management of data in these buffers has traditionally followed a first-in first-out procedure. In other words, the data that has been input to the buffer at the first, the oldest data, is the data that is output the first. These buffers are used for both read and write operations to storage locations on the hard file. Another technique for managing data in such a buffer is the last-in first-out procedure. In the last-in first-out procedure the last data provided to the buffer is the first data that is output from the buffer.
It is the object of the present invention to provide a data buffer for interfacing to a mass memory storage device that includes a technique to optimize the storage of data which has not been specifically requested but is anticipated to be requested.