A vector processor is closely integrated with a scalar processor. The scalar processor provides virtual-to-physical memory translation for both scalar and vector operations. In vector operations, a block move operation preformed by the scalar processor is intercepted, the write command in the operation is converted to a read, and data resulting from a vector operation is returned to the address specified by the block move write command. Writing of the data may be masked by a prior vector operation. Prefetch queues and write queues are provided between main memory and the vector processor. A microinstruction interface is supported for the vector processor.