THE OFFICER IN THE VEHICLE ENTERS A DIGITAL MESSAGE ON THE DIGICOM UNIT AND TRANSMITS IT AS A TONE-CODED BURST OVER THE VOICE CHANNEL TO THE BASE STATION. AT THE BASE STATION, THE INFORMATION IS DECODED AND ENTERED INTO A MINICOMPUTER WHICH TRANSFERS AND DISPLAYS THE DIGITAL INFORMATION TO THE DISPATCHER OR TO THE PIN/AUTOSTATIS (POLICE INFORMATION NETWORK/AUTOMATIC STATEWIDE AUTO THEFT INQUIRY SYSTEM) OPERATOR. DIGITAL INFORMATION FROM THE BASE STATION ORIGINATES AT THE COMPUTER OR IS ENTERED VIA A KEYBOARD. WHEN THE CHANNEL IS CLEAR THE COMPUTER OUTPUTS THE DIGITAL MESSAGE TO AN ENCODER FOR TRANSMISSION OVER THE VOICE CHANNEL TO THE PATROL CARS. VOICE TRAFFIC ORIGINATING WITH THE DISPATCHER OR FIELD PERSONNEL IS MONITORED BY THE COMPUTER. THIS CAPABILITY PROVIDES EXACT DATA ON CHANNEL CONGESTION AND ASSURES THAT THE DIGITAL SYSTEM IS SECONDARY TO VOICE AT ALL TIMES. AFTER EACH DIGITAL TRANSMISSION, THE COMPUTER CHECKS IF ANYONE HAS INITIATED VOICE CONTACT. IF SO, DIGITAL TRANSMISSIONS ARE STOPPED UNTIL THE CHANNEL IS AVAILABLE. (AUTHOR ABSTRACT)