I've uncovered some strange behavior of the adc10_open_unit function.
When I disconnect the ADC-12 from the parallel port and call adc10_open_unit(...) from my application I get 1 back which means that the function succeeded (Wrong!). All calls to adc10_get_value() after that return 4095. Does it look normal or it is a bug? I want the user to have an ability to see that device is unplugged if this is the case and correct the problem.