The Ei16C552 is an enhanced dual channel version of the Ei16C550 Universal Asynchronous Receiver Transmitter (UART). The device serves two serial input/output interfaces simultaneously in microcomputer or microprocessor based systems. Each channel performs a serial-to-parallel conversion on data characters received from peripheral devices or modems, and a parallel-to-serial conversion on data characters transmitted by the CPU. The complete status of each channel of the dual UART can be read at any time during functional operation by the CPU. The information obtained includes the type and condition of the transfer operations being performed, and error conditions. In addition to its dual communications interface capabilities, the Ei16C552 provides the user with a fully bidirectional parallel data port that fully supports the parallel Centronics type printer. The parallel port, together with the two serial ports, provide IBM PC ATTM and PS2 compatible computers with a single device to serve the three system ports.