Abstract: Disclosed is a mobile incident logger for monitoring an on-board, automotive, computer and signal levels developed by analog and digital sensors, the logger employing a coverage monitor, which records which memory locations are accessed by the computer; a cycle tag counting unit, which counts bus cycles of the computer; a discriminator, which detects the occurrence of incidents the logger is to record; a trace memory unit, which stores bus states of the computer; a trace memory unit, which stores memory variables of the computer; a discriminator, which detects the occurrence of some of the incidents the logger is to record; and a trace memory unit, which stores the sensor signals.