Abstract: A method and apparatus for testing bar code reader devices. A computer is programmed to receive data indicative of output signals of input devices for reading symbologies and to produce signals representative of those corresponding to the output of an input device. The computer then sends these representative signals to a subject bar code reader and receives the resulting signals produced by the reader. The computer also compares the received resulting signals with the representative signals to determine any differences. If the differences are judged to be significant, the computer produces an indicative signal.