To enable full functionality of the K14 gun sight there are several things 
that need to be done.  

First change the <nasal> section of your *set.xml file so that it looks like the 
following.  

<nasal>
   <!-- your other nasal files -->
   <!-- the following three lines must be exactly like this -->
   <K14>
      <file>Aircraft/Instruments-3d/computing-gun-sights/Nasal/lead-computer.nas</file>
   </K14>
</nasal>

Animation:

For dark conditions when cabin/cockpit illumination is used all of the K14 sight 
is illuminated in response to 

<property>/controls/lighting/cabin-norm</property>

If you are using a different property for your cabin/cockpit lights you will need to map your 
lighting property to /controls/lighting/cabin-norm.

Aircraft Specific Properties:

See README.lead-computer
														
Below is an example from the P-51D using the K14A sight which needs some additional
settings to control power and lighting for the sight.

<controls>
  <armament>
     <gunsight>		
		<!-- gunsight computer parameters -->
        
        <!-- start/stop the sight computer
       	     the computer will be reinitialized if the power is cycled -->	
        <computer-on type="int">0</computer-on>			 	
        <!-- offset of guns below sight line in feet -->		
		<z-offsetFeet type="float">3.125</z-offsetFeet>
		<!-- average lateral offset of guns in feet relative to sight line -->
        <y-offsetFeet type="float">0.0</y-offsetFeet>
		<!-- elevation of guns relative to alpha in degrees -->
        <gunElevationDegrees type="float">1.0</gunElevationDegrees>
        <ballisticCoefficienct type="float">0.00136354</ballisticCoefficienct> <!-- 0.50 BMG -->
        <muzzleVelocity type="float">2900.0</muzzleVelocity>  <!-- feet per second 0.50 BMG -->
		<!-- convergence distance in feet -->
        <gunHarminizationRangeFeet type="float">900.0</gunHarminizationRangeFeet>
		<timeStep type="float">0.2</timeStep>  <!-- cycle rate of gun sight computer in seconds -->
		<!-- sight computer damping factor must be between 0.3 and 1.0 -->
		<dampingFactor type="float">1.0</dampingFactor>	
		<gunsight-computer-initialized type="int">0</gunsight-computer-initialized>
		<maxAzimuth type="int">170</maxAzimuth>  <!-- maximum sight deflection in mils -->
		<maxElevation type="int">170</maxElevation>
		
		<!-- K14 parameters -->
		
		<power-on type="int">0</power-on>
        <intensity type="float">1.0</intensity>
		<mask-off type="int">1</mask-off>
		<reticleSelectorPos type="int">0</reticleSelectorPos>
		<rocketLadder type="int">1</rocketLadder>  <!-- set to 0 for K14 and 1 for other K14 models -->
		
		<!-- The next three are to setup the reticle to the correct starting values -->
		<span type="int">30</span>
		<mils type="float">0.0</mils>
		<range type="float">1000.0</range> <!-- in feet -->
		
		<fixedReticleOn type="int">0</fixedReticleOn>
		<zCenterLine type="float">0.7375</zCenterLine> <!-- sight line distance from model z axis in meters -->
		<K14C type="int">0</K14C>  <!-- set to 1 for K14C -->
		
		<sunScreenDown type="int">1</sunScreenDown>
     </gunsight>
   ...
</controls>