Abstract: A device controller for interfacing a host computer with an external storage device has an autohost controller. The device controller, at the end of a read operation, fills a memory buffer with data blocks contiguous with the read operation. On a subsequent read operation, the autohost controller checks the subsequent read operation and, if the requested data is within the memory buffer, directs the device controller to transfer the data from the memory buffer without intervention from an external microprocessor. If the autohost controller does not intervene, the device controller operates under the control of the microprocessor, as normal.