Interface device for converting a computer printer port into an input/output port

Claim 1

An interface device which is adapted to convert a computer printer port, having a number of data terminals for outputting N data signals from a computer for selecting one of N sensors, a strobe terminal for outputting strobe signals from the computer, a status terminal for receiving status information and a request terminal for receiving a request signal for the next data output, into an input/output port adapted to select one of the N sensors and then feed a status signal representing the status of the selected sensors back to the computer, said interface device comprising: connecting means adapted to be connected to receive and latch the N data signals and the strobe signals from the computer printer port and output the status information and the request signal to the computer printer port; and logic means connected to said connecting means to receive the N data signals for selectively monitoring one of said N sensors and providing status signals to said connecting means, in response to the N data signals strobed from said connecting means and the status of the selected sensor, said connecting means providing status signals of the selected sensor to said status terminal and said request terminal of said computer printer port via said connecting means. said logic means comprising a plurality of NAND gates, each having a first input connected to receive said N data signals of said connecting means, and a second input connected to said N sensors, the output of said NAND gates being connected in an OR configuration and adapted to provide the status signals of the selected sensor to said connecting means.