Abstract: A retrofit apparatus is connected to an existing bar code inventory system that includes a bar code corresponding to bar code markings, a bar code wedge to reader to generate a set of digital output signals transform the digital output signals into corresponding computer data characters, and a computer connected to the bar code wedge to process the computer data characters. A mobile transceiver is connected to the bar code reader. The mobile transceiver transmits wireless bar code signals corresponding to the digital output signals from the bar code reader. A receiver in the mobile transceiver is activated for a predetermined period of time after the wireless bar code signals are transmitted. A base transceiver is connected to the bar code wedge to receive the wireless bar code format output signals and to link them to the computer through the bar code wedge. If the computer receives a valid signal, it generates an acknowledge signal that is passed through the bar code wedge to the base transceiver.