Microcomputer system bidirectional input-output buffer - uses flip=flop controlled driver for simultaneous input-output and operations

摘要

A microcomputer bidirectional input-output buffer is used for coupling input-output terminals to a data bus with a controlled driver which is opened or closed by control signals. In the open condition data from the input-output terminal highway is passed to the data bus and in the closed condition data transfer is blocked. It is designed to enable smooth access to terminal and working store under user program control. Input-output operations are controlled simultaneously with working store read and write commands. The driven (25) is controlled via a flip-flop acting on read and write commands to connect or disconnect the buffer register and data bus. A read buffer is controlled by read instructions.