Abstract: An apparatus for conducting input output operations with another data processing device in a flexible and low cost manner is comprised of a programmed microprocessor coupled to a keyboard, a parallel port, and a modem. The microprocessor is programmed to periodically scan the keyboard to determine what keys if any are depressed. It also scans the parallel port for incoming data and senses incoming data from the modem by sensing a start bit. Control characters from the keyboard can set options such that incoming data from an input can be simultaneously sent out from the modem and/or parallel port.

Abstract: There is disclosed herein an apparatus for displaying data and communicating with another data processing device via a parallel port or over a long distance communications network via a full duplex modem, said computer terminal utilizing a microprocessor for programmed control of the terminal. The terminal is capable of displaying information on a standard black and white television set and utilizes a keyboard for entering information to be displayed or sent to the main data processing system. Limited graphics with sixty four graphics patterns are also available by using the microprocessor chip to scan the keyboard and communicate with the modem and parallel ports, and by utilizing a standard television set instead of a cathode ray tube, substantial material cost savings can be made in building the terminal which could be built for under $250 in parts in 1979.