1. A control apparatus in an image scanner comprising: a host computer interface for exchanging information with an attached host computer; and a process control module for controlling real time operations of the image scanner wherein said process control module is adapted to accept low-level control instructions received from the attached host computer via said host computer interface wherein said process control module includes at least one control/status data structure directly addressable by the host computer by said low-level control instructions for control of the state of the image scanner by the host computer and for reporting the state of the image scanner to the host computer.