A compact, desktop document processor for capturing data and images from checks and other financial and payment-related documents includes a modular base unit. In one embodiment, the application servers are organized into groups referred to as \u201cinstances. If the detected signal level does not match the given value, the TSG controller selects an initial preset tuning state from a pre-established trajectory corresponding to a pre-identified operating condition that best matches a current operating condition. By monitoring an output signal of the light detector based on the directed light, control circuitry can detect that a position of an element of the system has changed. Security measures inhibit video game piracy.