1. A microcomputer system comprising: (A) a microcomputer device formed in a single integrated circuit and having data input/output terminals and address terminals; (B) memory means external to the microcomputer device having address input terminals and data output means; (C) input/output peripheral means for transfer of information to or from external equipment, said peripheral means having address input means and data input/output means; (D) external address bus means coupled to the address output terminals of the microcomputer device, and coupled to the address input means of said peripheral means and to the address input terminals of said memory means; (E) external data bus means coupled to said data input/output terminals of the microcomputer device, and coupled to the data input/output means of said peripheral means and the data output means of the memory means; (F) the microcomputer device comprising within said integrated circuit: an arithmetic/logic unit having data input and data output; a first read/write memory having an address input and having data input/output means; internal data bus means coupled to the data input and data output of the arithmetic/logic unit and coupled to the data output of the arithmetic/logic unit and coupled to the data input/output means of the first read/write memory; a second read/write memory having an address input and having data input/output means, the second read/write memory storing data or instruction words; data memory address means connected to said address input of said first and second read/write memories for storing destination addresses specified by an instruction word program address means connected to the address input of the second read/write memory; internal program bus means coupled to said data input/output means of said second read/write memory, to said data input/output terminals, and coupled to said program address means; control means having an input coupled to said program bus means and generating microcontrol signals in response to instruction words, the microcontrol signals defining operation of the arithmetic/logic unit and controlling the transfers to and from the internal bus means; said control means including means for executing a first block-move instruction for copying a series of sequential memory address contents from the external memory means to the first read/write memory, and a second block-move instruction for copying a series of sequential memory address contents from the external memory means to the second read/write memory, where in each of said first and second block move instructions the addresses for said series are generated from said program address means, and the destination addresses in said first or second read/write memory are generated in said data memory address means when executing an instruction before the first block-move instruction.