Interface apparatus for coupling a minicomputer to a microcomputer for the transfer of data between them and method for using same

摘要

Interface apparatus which facilitates asynchronous parallel transfer of data at a speed of up to at least 1.6 megabits per second between a minicomputer and a microcomputer. The apparatus includes a plurality of bidirectional data circuits parallel coupled between the minicomputer and the microcomputer for carrying data between the minicomputer and the microcomputer when either computer wants to send data to the other computer. The apparatus also includes data transfer control circuitry coupled between the minicomputer and the microcomputer for permitting either computer, when it wants to send data, to: (a) indicate by means of a first or second control signal to the receiving computer that the sending computer wants to transmit data over the data circuits, (b) resolve contention between the computers for access to the interface apparatus, (c) enable the receiving computer to indicate to the sending computer that the receiving computer is ready to receive data over the data circuits, (d) effect transfer of data from the sending computer to the receiving computer over the data circuits, and, (e) enable the receiving computer to indicate to the sending computer that the receiving computer has received the data.