System for alternatively transferring data from external memory to memory device and from memory device to internal memory depending upon processing unit's operational

摘要

A system for high speed data transfer between an external memory and internal memory of a computer is disclosed. The system contains a CPU, two memory devices, a first circuit for communicating data with the external memory, a second circuit for communicating data with the internal memory, a data switch for alternatively connecting the two memory devices to the first and the second circuit, and a software routine. The software routine causes the data switch to couple one of the memory devices to the internal memory when the CPU is available to process data. The software routine also causes an application program to be executed by the CPU when data is transferred between the external memory and one of the memory devices.